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The GL of Your Diet Determines Your Future Dementia Risk

The GL of Your Diet Determines Your Future Dementia Risk

by Patrick Holford

high glycaemic load diet

Why Blood Sugar Exposure Matters More Than Sugar Itself

Your brain uses more glucose for energy than any other organ in the body.

From that simple fact comes a widespread assumption: that sugar fuels the brain and therefore more sugar must mean more mental energy.

In reality, the opposite appears to be true.

A large new study shows that the glycaemic load (GL) of your diet, which reflects how much glucose you expose your bloodstream to over time, is strongly linked to your future risk of dementia. The higher the glycaemic load, the higher the risk.

In this study, people consuming more than 110 GL units a day had a 13% higher risk of developing dementia. Those consuming less than 49.3 GL units a day had a 17% lower risk. In other words, the difference between a high GL diet and a low GL diet translated into a 30% swing in dementia risk.The study, published in the International Journal of Epidemiology, analysed dietary data from over 200,000 UK Biobank participants in 2011–12 and followed them for more than a decade to see who did, and did not, develop dementia (1).¹

Most people’s diets exceed 100 GL units a day. I have been advocating a daily intake of around 45 to 60 GL units since the 1990s. To understand why this matters, and what it means for what you eat, it helps to understand what GL actually is.

How Much Sugar Your Body Really Needs

As petrol is for your car, glucose is the primary fuel for your body. Glucose is the main fuel used by all cells.

There is also another fuel, ketones, much like cars can also run on electricity. We too are metabolic hybrids.

Now here is an astonishing fact. Your body contains around 100,000 kilometres of blood vessels. Your brain alone has around 1,000 kilometres of them. These vessels supply energy to around 30 trillion cells, each containing roughly 1,000 mitochondria, the tiny energy factories that power life.

And yet, across this entire system, there only needs to be around 4 grams of glucose in your bloodstream at any one time. That is one teaspoonful. That is all that is required for every cell in your brain and body to have energy at that moment.²

GL is a measure of how much glucose enters your bloodstream after eating or drinking a food. If there is not much glucose in the food, and you use it quickly, perhaps by moving or exercising, blood sugar levels stabilise rapidly.

The glycaemic load of a food depends on two things:
• the quality of the carbohydrate
• the quantity eaten

Quality refers to how fast glucose is released, known as the glycaemic index (GI). Fibre and protein slow this release. This is why white rice has a higher GI than brown rice, which contains fibre. Eat rice with fish, beans or meat, and the protein slows the release further.

GL also depends on portion size. A small serving of brown rice with fish is low GL. A large serving of white rice, even with fish, is high GL.

When Glucose Becomes Toxic to the Brain

What happens if you consume far more glucose than the body needs?

A can of sugary fizzy drink contains around 35 grams of sugar. That is roughly nine times more glucose than the total amount normally circulating in your bloodstream.

This excess is toxic. It damages blood vessels and the tissues they supply. Diabetes is diagnosed precisely because excess sugar damages the kidneys, eyes and nerves. The brain is no exception.

“The brain needs more energy than any other organ, so it contains the most mitochondria. Sugar damages mitochondria,” says Professor Robert Lustig, Professor of Neuroendocrinology at the University of California, San Francisco. If you have read Upgrade Your Brain or Alzheimer’s: Prevention is the Cure, you will already know that high sugar intake, sugary drinks and ultra processed foods increase dementia risk, worsen memory even in young people, and are associated with measurable shrinkage of brain regions involved in memory in teenagers.

Are You Eating Too Much Hidden Sugar?

The simplest way to assess your long term blood sugar exposure is to measure HbA1c.

HbA1c literally means sugar damaged red blood cells. If more than 6.5% of your red blood cells are sugar damaged, you are diagnosed with diabetes. Above 6% indicates pre diabetes. Even levels above 5.4% in teenagers predict brain shrinkage.

For optimal health you want to be below 5.4%, and ideally below 5%.

HbA1c is such a strong indicator of blood sugar resilience that it is included in Food for the Brain’s 5-in-1 DRIfT home blood test kit.

Balancing Blood Sugar with a Low Glycaemic Load Diet

Let us start with something simple.

An orange contains sugar, but also fibre and micronutrients. The fibre slows sugar release, mainly fructose, which takes time to convert to glucose, while feeding beneficial gut bacteria.

A glass of orange juice, however, contains the sugar of around three oranges, without the fibre. Three times the sugar, with no brakes. Eat your fruit. Do not drink it.

When you eat sugar or starches such as rice, digestive enzymes rapidly break them down into glucose. Protein, by contrast, takes several hours to digest into amino acids. This slows carbohydrate digestion further down the digestive tract.

This leads to a simple rule: eat carbohydrates with protein.

Brown rice releases glucose more slowly than white rice. Add beans, fish or meat, and the release slows further.

From this we can extract three practical rules:
• Eat fruit. Do not drink it
• Always eat carbohydrate with protein
• Make fibre the primary ingredient of every meal

What a Low GL Meal Actually Looks Like

Compare these two breakfasts:

Cornflakes with a banana or Oats with chia seeds and berries

Cornflakes are fast releasing sugar. Oats are slow releasing. A banana raises blood sugar more than two bowls of berries.

Chia seeds, rich in soluble fibre, dramatically slow sugar release. A portion of oats with chia and berries is around 10 GL. Cornflakes and a banana can reach 30 GL.

You want meals around 10 GL and snacks around 5 GL. Three meals and two snacks equals around 40 GL per day.

Eat 40 GL per day to lose weight. Around 60 GL to maintain it.

Eat little and often, and start the day with a low GL breakfast.

A friend of mine, Dr David Unwin, who is  a leading diabetes doctor, converted our low GL calculations into ‘teaspoons of sugar equivalent’ to give a visual idea to his diabetic and overweight patients of how sugar is hidden in common foods. See the table below.

Food GIServing size GLTeaspoons of sugar
Cereals
Coco Pops7730g207.3
Cornflakes9330g228.4
Mini Wheats5930g134.4
Shredded Wheat6730g144.8
Special K5430g124.0
Bran Flakes7430g134.8
Porridge63150ml62.2
Bread
White7130g103.7
Brown7430g93.3
Rye (69% wholegrain rye flour)7830g114.0
Wholegrain barley (50% barley)8530g155.5
Wholemeal (stoneground flour)5930g72.6
Pitta (wholemeal)5630g82.9
Rough oatcake3510.4g20.7
Fruit
Banana62120g165.9
Grapes (black)59120g114.0
Apple (Golden Delicious)39120g62.2
Watermelon80120g51.8
Nectarines43120g41.5
Apricots34120g31.1
Strawberries40120g10.4

Adapted, with permission, from David Unwin’s charts in the Journal of Insulin Resistance (2016) 

The Balance of Your Plate

Half your plate should be vegetables and fruit. A quarter should be protein. A quarter carbohydrate.

Vegetables supply antioxidants that neutralise the exhaust fumes produced when mitochondria burn fuel. This becomes more important as we age and mitochondrial efficiency declines.

Protein slows sugar release and provides essential building blocks. Carbohydrate portions must be modest.

Whole grains and starchy vegetables vary widely in GL. Wholemeal pasta and brown basmati rice are far better than white pasta or white rice. Swedes, carrots and squash are better than potatoes. Boiled potatoes are better than baked. French fries are the worst of all.
all.

Starchy vegetables and cereals
Pumpkin/squash
Carrot
Swede
Quinoa (cooked)
Beetroot
Cornmeal
Pearl barley (cooked)
Wholemeal pasta (cooked)
White pasta (cooked)
Brown basmati rice (cooked)
White rice (cooked)
Couscous (soaked)
Broad beans
Sweetcorn
Boiled potato
Baked potato
French fries
Sweet potato
7 GL points
1 large serving (185g)
1 large (158g)
1 large serving (150g)
1 large serving (120g)
1 large serving (112g)
1 serving (116g)
1 small serving (95g)
half a serving (85g)
a third of a serving (66g)
1 small serving (70g)
a third of a serving (46g)
a third of a serving (46g)
1 serving (31g)
half a cob (60g)
3 small potatoes (74g)
half (59g)
a tiny portion (47g)
half

Beans and Lentils: Nature’s Blood Sugar Regulators

Beans and lentils are uniquely effective because they contain both protein and carbohydrate in one food. This keeps their GL low while allowing generous portions.

When combining beans with other starches, reduce the starch portion by half. A cup of lentils with half a cup of rice, not equal amounts.

By applying these principles you can restore blood sugar control, regain energy, reduce dementia risk, reverse type 2 diabetes and improve cognitive clarity.

The Proof Is in Your HbA1c

Red blood cells live for around three months. Follow a low GL diet for three months, then retest HbA1c.

This approach is detailed in The Low GL Diet Cookbook. Specific supplements can accelerate recovery, including fibre such as glucomannan, chromium and cinnamon compounds to improve insulin sensitivity, and HCA from tamarind to promote glucose burning rather than storage.

What to Do Next

If glycaemic load affects dementia risk, the next step is simple: measure, act, and check again.

Test your blood sugar resilience.

HbA1c shows how much sugar damage has occurred over the last three months. It is included in Food for the Brain’s DRIfT 5-in-1 home test, alongside other key brain health markers. If HbA1c is high, a low GL diet gives you a clear way to bring it down.

Check how your brain is functioning now.

The free Cognitive Function Test takes around 20 minutes and provides an objective snapshot of memory, attention and processing speed. Many people spot early changes years before any diagnosis.

Make changes, then retest.

Follow a low GL diet for three months, then re-test HbA1c and cognitive function to see whether the changes are working.

Prevention works best when it is measured.

References:

Further info

A Better Festive Treat: Black Bean Brownies That Support Blood Sugar and Brain Health

A Better Festive Treat: Black Bean Brownies That Support Blood Sugar and Brain Health

If you find yourself craving more sugar at this time of year, there’s nothing wrong with you – your biology is responding to a month where blood sugar swings are almost guaranteed. 

But cravings aren’t a sign of weakness. They’re a sign your blood sugar, gut, and brain chemistry are under strain – which is why fibre-rich festive recipes can make such a powerful difference.

This week’s recipe does exactly that. These black bean brownies feel indulgent, but underneath they’re designed to support stable blood sugar, calm cravings, and keep your brain sharper through the most sugar-heavy month of the year.

And yes: they taste genuinely delicious.

Why Sugar Affects Your Brain and Memory

Sugar doesn’t just influence your waistline and energy – it directly affects the structure and functioning of your brain. Glucose is the brain’s primary fuel, but when levels rise too high or fluctuate too quickly, the brain experiences this as stress. Over time, those swings change how the brain ages.

Large population studies show that even slightly elevated glucose levels – levels many people would consider “normal” – significantly increase dementia risk (1). And when HbA1c rises, it shows that your body has been exposed to higher glucose levels over the past 8–12 weeks. This matters because long-term elevated glucose drives inflammation, damages blood vessels in the brain, and accelerates the processes linked to cognitive decline (2).

Even in younger or otherwise healthy adults, small rises in glucose are associated with reduced volume in the hippocampus – the brain’s centre for memory, learning, and emotional regulation (3). This means that sugar isn’t only an issue for diabetes prevention; it’s directly tied to how well your brain can store information, retrieve memories, and stay resilient across your lifetime.

During the festive period, these glucose swings become more common – thanks to grazing, disrupted routines, and richer foods. It’s not the single dessert that matters, but the repeating pattern. And your brain feels every one of those peaks and dips before your waistline every does.

How to Tell If You’re Eating Too Much Sugar (Using HbA1c)

This is where measuring your HbA1c becomes incredibly useful.

HbA1c reflects how much of your red blood cells have been exposed to glucose over the past 8–12 weeks, giving you a true picture of your overall sugar load – not just what you ate yesterday, but whether your body is regularly receiving more carbohydrate than it can comfortably handle. We all have slightly different carbohydrate tolerance, and HbA1c shows you where your line is.

It’s also one of the most powerful early indicators of long-term brain health. Higher HbA1c is linked with faster cognitive decline and a greater risk of dementia, even in people who don’t meet the criteria for diabetes (2). Keeping your sugar intake – and therefore your HbA1c – in a healthy range is a core part of protecting your brain.

But glucose is only one part of the story.

When you look at HbA1c alongside other biomarkers such as homocysteine and the omega-3 index, you get a much richer picture of how well your brain is being supported. These markers reflect inflammation, nutrient status, membrane structure and repair – all of which influence how resilient your brain is to the effects of oxidative stress and high blood sugar. When any of them drift out of range, the brain becomes more vulnerable.

This is exactly why our DRIfT test brings these three measures together.

Between HbA1c, homocysteine, and omega-3 status, you gain a personalised, science-based understanding of how your current diet and lifestyle are shaping your cognitive future.

And if your HbA1c is starting to rise, it’s an early signal that your brain has been exposed to more glucose than it can comfortably manage – a gentle nudge to make adjustments now, rather than years down the line. Order your DRIfT test here – and for the first time ever – we’ve reduced the DRIfT 5-in-1 test by 20% this weekend to widen access to early detection and support our prevention research.

Why Fibre Helps Reduce Sugar Cravings (Especially in December)

This is the part most people underestimate.

A high-fibre diet:

  • slows glucose entering the bloodstream,
  • reduces cravings,
  • stabilises energy, and
  • supports better long-term glycaemic control.

A large systematic review published in The Lancet found that diets higher in fibre significantly improved blood sugar control, lowered HbA1c, and reduced diabetes risk (4).
During a month where treats are everywhere, fibre becomes one of the simplest tools to protect your metabolic and cognitive health. (Gut health is one of our nutrition and lifestyle domains on our COGNITION™ programme – free to all our FRIENDS)

Which is why these brownies work so well…

Most festive treats are low-fibre and high-sugar – a combination that sends cravings soaring.

These brownies flip that on its head.

With black beans, oats, and chicory root syrup, each brownie contains:

  • ~5.4g fibre
  • ~3g protein
  • ~6g fat
  • ~9g carbs
  • low GL (≈ 3.9)

This gives you the sweetness without the spike – and the fibre slows digestion so you don’t end up reaching for “just one more”.

Serve them with thick Greek yoghurt and fresh raspberries for extra balance and natural sweetness.

High-Fibre Black Bean Brownie Recipe (Low GL, Gluten Free)

Ingredients

  •  1 tin black beans, drained & rinsed very well
  • 6 tbsp cocoa powder (30g)
  • 40g oats
  • 1 egg
  • 1/4 tsp salt
  • 4–6 tbsp sweetener of choice (chicory syrup or brown-sugar substitute work well)
  • 4 tbsp coconut oil
  • 2 tsp vanilla extract
  • 1/2 tsp baking powder

Method:

Preheat oven to 170°C.
Blend all ingredients in a food processor until completely smooth.
Pour into a lined 8×8 tin.
Bake for 15–18 minutes.
Cool for at least 10 minutes before slicing.
If still soft, chill in the fridge overnight – they firm up beautifully.

Check Your HbA1c, Omega-3 and Homocysteine With Our DRIfT Test

Fibre-rich recipes can help – but the real insight comes from knowing your HbA1c.

Our DRIfT 5-in-1 at home blood test measures your:

  • HbA1c (blood sugar control)
  • Omega-3 Index
  • Vitamin D
  • Homocysteine
  • Glutathione
    Available to purchase globally – order yours here

It’s one of the simplest ways to understand how sugar is affecting your long-term brain health – and what to do next to protect it.

Also, if you haven’t completed the FREE and validated online Cognitive Function Test then do that together too get instant personalised feedback on your brain health.

For more recipes – subscribe to the Upgrade Your Brain Cook App.

References:

  1. Crane PK et al. Glucose levels and risk of dementia. N Engl J Med. 2013;369(6):540–548.
  2. Rawlings AM et al. Diabetes, prediabetes and cognitive decline. Diabetes Care. 2019;42(7):1217–1224.
  3. Kerti L et al. Higher glucose levels relate to lower hippocampal connectivity and cognition. Neurology. 2013;81(20):1746–1752.
  4. Reynolds A et al. Carbohydrate quality and human health: systematic review. Lancet. 2019;393(10170):434–445.

Further info

Why Sleep is Your Metabolic Superpower

Why Sleep is Your Metabolic Superpower

We tend to think of sleep as rest – the way we replenish energy.  In truth, your sleeping hours are a highly productive repair shift, especially for your metabolism

Each night, your body resets blood sugar, clears metabolic waste, restores energy and even rewires memory. Consistently missing out on quality or quantity of sleep means less of that vital repair work gets done.

Most people notice tiredness after a bad night, but few realise the impact it has on their blood sugar, metabolism and even body composition.

So in our last article we explored melatonin’s role in brain repair, in this part 2 we look at how poor sleep throws off your body’s entire metabolic rhythm – from blood sugar to fat storage.

(When we talk about poor sleep, we mean getting less than seven hours a night, sleeping at irregular times, or waking often through the night – all of which disturb the deep, restorative phases your brain depends on.)

Sleep and insulin: two sides of the same coin

Deep, unbroken sleep keeps your cells sensitive to insulin, the hormone that allows glucose into cells to make energy. Cut the night short and this system falters. Just one poor night can reduce insulin sensitivity by about 25 per cent (1).

That means glucose lingers in the bloodstream (creating inflammation over time) while your brain cells are left hungry for fuel.

The result? Brain fog, irritability, and a body craving quick fixes – sugar, caffeine and refined carbohydrates. You’ll have felt this yourself: after a poor night’s sleep, you wake up wanting pastries or toast, not eggs and greens.

The “tired brain” that acts diabetic

When the brain can’t get enough glucose, it flips into survival mode.

Stress hormones like cortisol and adrenaline surge to keep you going, but they also spike blood sugar and wreck the next night’s sleep (hello, 4 a.m. wake-ups).

Brain scans show that after even a single sleepless night, glucose metabolism in the prefrontal cortex, the region responsible for focus and decision-making, drops sharply (2).

It’s a vicious cycle: sleep loss drives insulin resistance, which drives stress and sugar intake, which drives more sleep loss.

Poor Sleep Changes Your Metabolism

It’s easy to see how poor sleep doesn’t just fog your mind – it rewires your metabolism. Short sleep duration is now recognised as one of the strongest lifestyle predictors of weight gain, insulin resistance and type-2 diabetes – even when calorie intake stays the same,

Even a few nights of shortened sleep raise ghrelin, the hunger hormone, and suppress leptin, which signals fullness (7). The result is stronger cravings for quick-release carbs and sugary snacks, precisely the foods that destabilise blood sugar and accelerate insulin resistance. At the same time, sleep loss changes how your body stores fat: studies show it increases visceral fat, the deep belly fat that drives inflammation (8).

Over time, this mix – more hunger, higher insulin, greater inflammation – pushes many people toward weight gain, pre-diabetes and, eventually, cognitive decline.

So if you’re trying to lose weight or steady your energy, don’t forget about sleep.

High blood sugar, low cognition

Poor sleep raises blood sugar, and when glucose stays high, the brain pays the price.

Overtime poor sleep raises blood sugar, and when glucose stays high, the brain eventually pays the price. Chronically elevated HbA1c, measured in our DRIfT test, predicts faster cognitive decline and higher dementia risk. The same metabolic stress that drives weight gain and diabetes also drives neurodegeneration. That’s why people with insomnia or sleep apnoea are far more likely to develop both type-2 diabetes and Alzheimer’s (3, 4).That is why we cover both sleep and insulin management as a key part of our COGNITION 6-month brain upgrade programme (available to all FRIEND’s of Food for the Brain) – because protecting your brain is possible when you know what to focus on.

The night-shift hormones that matter

  • Melatonin isn’t just for sleep – it fine-tunes your body’s glucose rhythm and acts as a powereful antioxidant. When evening light suppresses it, next-morning blood sugar shoots higher (5).
  • Cortisol should fall overnight so insulin can do its work; if stress, late eating or light keeps it high, blood sugar stays stuck.
  • Growth hormone, released in deep sleep, repairs tissue and builds lean muscle, your natural blood-sugar buffer.

Together these hormones keep the night restorative and the brain calm. Disrupt them and the same chemistry that fuels diabetes starts fuelling Alzheimer’s (6).

Simple Ways to Turn Sleep into a Metabolic Superpower

  1. Guard your 7–8 hours. Deep sleep is where metabolic reset happens.
  2. Skip caffeine or alcohol late. Both fragment sleep and blunt insulin response.
  3. Finish eating at least three hours before bed. Giving your body time to fast allows insulin to fall and encourages fat use for fuel overnight.
  4. Start your day with light, not sugar. Early daylight synchronises your circadian rhythm, boosting morning cortisol naturally so you rely less on coffee and quick carbs.
  5. Pair protein-rich, low-GL meals with consistent sleep. Balanced blood sugar by day supports stable melatonin and growth hormone at night, a feedback loop that keeps your metabolism working for you, not against you. Find 100+ delicious recipes here.https://foodforthebrain.org/uybcookapp/

Sleep as metabolic medicine

Sleep isn’t a luxury or a waste of time –  it’s your brain’s way of resetting and restoring the entire body. It shapes body composition, curbs cravings, steadies energy and supports the metabolism that powers your mind.

Takeaway: good sleep, like good nutrition, is prevention in action.
Want to dive deeper? Join us for the Sleep Solution Webinar with sleep scientist Greg Potter. Find out more here

Reference:

  1. Spiegel K et al. Impact of sleep debt on metabolic and endocrine function. Lancet. 1999;354(9188):1435–9.
  2. Benedict C et al. Acute sleep deprivation reduces energy expenditure and brain glucose metabolism. Sleep. 2012;35(7):981–8.
  3. Yaffe K et al. Sleep duration and risk of type 2 diabetes: a meta-analysis. Diabetes Care. 2015;38(9):1633–40.
  4. Sabia S et al. Association of sleep duration in middle and old age with dementia incidence. Nat Commun. 2021;12:2289.
  5. Gooley JJ et al. Exposure to room light before bedtime suppresses melatonin onset and shortens its duration. J Clin Endocrinol Metab. 2011;96(3):E463–72.
  6. Musiek ES, Holtzman DM. Mechanisms linking circadian clocks, sleep, and neurodegeneration. Science. 2016;354(6315):1004–8.
  7. Spiegel K et al. Brief sleep curtailment decreases leptin, increases ghrelin, and causes increased hunger and appetite. Ann Intern Med. 2004;141(11):846–50.
  8. Nedeltcheva AV et al. Insufficient sleep undermines dietary efforts to reduce adiposity. Ann Intern Med. 2010;153(7):435–41.
Further info

Sugar, Metabolic Syndrome and Early-Onset Dementia: Is This Type 3 Diabetes?

Sugar, Metabolic Syndrome and Early-Onset Dementia: Is This Type 3 Diabetes?

Insulin molecule. Computer model showing the structure of a molecule of the hormone insulin. Insulin plays a key role in blood sugar regulation, released from the pancreas when blood sugar levels rise, for example after a meal. Impaired insulin signalling is not only central to diabetes but is also linked to “Type 3 diabetes,” a term used to describe insulin resistance in the brain that contributes to Alzheimer’s disease and dementia.

Why are more people in their 40s and 50s developing dementia? Most assume the answer lies in the genes. But here’s the reality: fewer than 1% of Alzheimer’s cases are caused by rare genetic mutations. The other 99%? They are driven largely by preventable, lifestyle-related factors – and at the centre of the storm is how we process sugar, , leading many scientists to describe Alzheimer’s as “Type 3 diabetes.”

A major new study of nearly two million people confirms that metabolic syndrome – the cluster of blood sugar imbalance, abdominal obesity, high blood pressure, and poor lipid levels  – significantly increases the risk of early-onset dementia.

This should be front-page news. Dementia is now affecting people in their 40s and 50s, not just the elderly. And at the heart of this early decline? Poor blood sugar control, excess abdominal fat, and the metabolic mayhem caused by high-sugar diets.

The Evidence: 24% Higher Risk of Dementia Before Age 65

The landmark 2024 study published in JAMA Neurology followed more than 1.9 million adults and found that those with metabolic syndrome had a 24% higher risk of developing dementia before the age of 65 compared with those without (1).

The strongest associations were observed with:

  • Hyperglycaemia (high blood sugar)
  • Abdominal obesity (visceral fat around the waist)

These two factors, when present together, were particularly predictive of vascular dementia, although risks were also elevated for Alzheimer’s disease and other forms of dementia.

The authors adjusted for other lifestyle and demographic factors, confirming that metabolic health itself was an independent driver. Men and those in their 40s showed the highest vulnerability.This aligns with decades of research linking insulin resistance and poor glucose control with brain shrinkage, memory loss, and neurodegeneration – all of which are discussed in detail in [here] and [here]. 

The Type 3 Diabetes Hypothesis

Scientists have increasingly referred to Alzheimer’s disease as “Type 3 diabetes” – a term that reflects how brain cells become resistant to insulin and fail to metabolise glucose properly.

Chronically high blood sugar damages blood vessels in the brain, increases inflammation, and accelerates the formation of amyloid plaques, all hallmark features of Alzheimer’s pathology. This new study provides the strongest population-level evidence to date that the same dysfunction is also driving younger-onset dementia.

The Role of Fructose and Processed Sugar

Endocrinologist and paediatric neuroendocrinologist Dr Robert Lustig has long warned of the unique effects of fructose (a sugar found in high-fructose corn syrup and added sugars) on the brain. Unlike glucose, fructose is processed in the liver, promoting visceral fat, insulin resistance, and inflammation – all central to metabolic syndrome (2).

When the brain is chronically exposed to excess sugar and insulin, its ability to generate energy and form new synapses becomes impaired. Over time, it is as if the brain is being starved, even in the midst of plenty.

 This isn’t just a long-term risk – we’re now seeing it play out in middle-aged adults.

Thankfully we know that there is much you can do to prevent this from happening – your future is in your hands – here is what to focus on.

What Can You Do? Five Simple Shifts

  1. Check your blood sugar regulation. The HbA1c test is a key marker of long-term blood glucose control. (Available via our home test kits and in our DRIfT 5 in 1 test kit.)
  2. Prioritise low-GL, whole foods. Swap out refined carbohydrates and processed sugars for whole grains, legumes, nuts, and non-starchy vegetables.
  3. Limit fructose. Reduce or remove sweetened drinks (including fruit juice), syrups, and processed snacks high in high-fructose corn syrup. Read more on high/low fructose foods here.
  4. Assess your waist size. Abdominal fat is a strong dementia risk factor. A healthy waistline helps protect your brain.
  5. Exercise regularly. Just 30 minutes a day improves insulin sensitivity and helps the brain use glucose more efficiently.

Need help taking action on the above? Struggle to know how to ditch your sweet tooth?

Join us in the Forget Sugar Webinar in October with Patrick Holford.

A Wake-Up Call, Not a Life Sentence

This study shows a sobering trend – but Food for the Brain exists to empower you in your prevention path. Early-onset dementia is not inevitable. It is largely preventable if you act now. Sugar, insulin resistance, and metabolic syndrome are right at the centre of the problem.

We need public health messaging that reflects this. Dementia is not just an age-related disease. It’s a lifestyle-driven brain disorder that begins years, even decades, before diagnosis.

Your brain doesn’t have to retire early – start your brain upgrade programme and journey today.Want to assess your brain health? Complete this free validated online Cognitive Function test to receive personalised insights into your brain health, along with guidance on what you can do to reduce your risk and protect your future!


References

  1.  Jang H et al. Association Between Metabolic Syndrome and Early-Onset Dementia in a Nationwide Cohort. JAMA Neurol. 2024. doi:10.1001/jamaneurol.2024.xxxxxx
  2. Lustig RH. Fat Chance: The Hidden Truth About Sugar, Obesity and Disease. Penguin; 2013.https://pubmed.ncbi.nlm.nih.gov/12450889/

Further info

How To Break Free From Food Addiction

How To Break Free From Food Addiction

woman eating cake

Do you ever promise yourself you’ll stop eating sugar or junk food – only to find yourself back at the biscuit tin a few hours later? You’re not alone. Food addiction is real. In fact, it can be as powerful and pervasive as alcohol addiction.

The first step is awareness. According to clinical psychologist Dr Jen Unwin, there are six warning signs. If you recognise yourself in two or more, it may be time to take this seriously.

Read on to see if any apply to you.

Six Signs You May Be Addicted to Food

1. Certain foods feel impossible to resist

 “You’re craving a certain food so badly that you feel compelled to eat it, even when you know you shouldn’t,” Dr Unwin explains. At the height of her own addiction, she would secretly make a bowl of cake mixture – just butter, sugar and flour -and eat the entire thing raw. “It sounds ridiculous now, but I had such intense cravings for sweet, soft, sugary foods,” she explains.

2. You always need more

Like alcohol tolerance, food addiction builds over time. “One slice of cake may have been enough in the beginning, but soon you need two, three – or half the cake – to get the same dopamine hit,” says Dr Unwin. She recalls eating slice after slice at her daughter’s wedding, unable to stop until she felt sick.

3. Food takes priority over everything else

A common factor in addiction is that you begin to ignore what you once valued and prioritise food above socialising, hobbies, family time and even work. Often, Dr Unwin would leave the house and her family in secret to drive for 20 minutes to a cinema complex where she would order a large tub of Ben & Jerry’s Cookie Dough ice cream with chocolate sauce. She would then return to her car and eat the entire portion, feeling ashamed and elated at the same time, before returning home an hour later as if nothing had happened.

4. You lose control once you start

You might buy biscuits for your grandchildren, planning to have just one with your tea. Before you know it, the whole packet has disappeared.

5. Withdrawal symptoms kick in

If you try to cut down on sugary snacks and carbohydrates, do you experience withdrawal symptoms? “These include headaches, migraines, gastrointestinal symptoms, low mood, anxiety, fatigue and brain fog,” Dr Unwin says. “As people experience sugar withdrawal, they feel so bad that they just go back to eating it.” When Dr Unwin completely abstained from sugar, she experienced many of these symptoms for eight days. But after pushing through that difficult period, she began feeling better than ever.

6. You know it’s harming you – and carry on anyway

According to Dr Unwin, this is the defining sign: eating damaging foods despite knowing the consequences. She references a patient with Type 2 diabetes who kept bingeing on cake and sugar knowing how bad it is for their blood sugar. People in this situation often know the food is harmful, but they feel trapped in a cycle.

Why Processed Foods Hijack Your Brain

Breaking free from any addiction is not purely a matter of willpower. Addictive foods and drinks hijack your brain’s chemistry, making you crave them. This effect is purposely done so that you keep buying more.

Understanding how certain food ingredients and combinations work in the brain unlocks the secret to undoing food addiction. The most powerful trigger is the combination of fat and sugar – the two key components of most junk foods. Think cakes, biscuits, ice cream, chocolate bars and pastries. This pairing presses the brain’s dopamine “reward” switch, creating intense pleasure in the moment but diminishing feelings of satisfaction over time. Just like drugs, it fuels cravings and loss of control.
This hijacking of the dopamine-based reward system doesn’t just drive overeating – it also increases the risk of cognitive decline and brain shrinkage. Additionally, it disrupts glucose control and drives insulin resistance, a well-known promoter of cognitive decline.  (Read more –  ‘Is Sugar Killing Your Brain?)

Nutritional Tools That Reset Your Brain

In Patrick Holford’s book How to Quit without Feeling S**t  he recommends strategies that help restore balance to your brain chemistry:

  • Omega-3 fats – vital for healthy cell membranes and for receiving neurotransmitter messages.
  • B vitamins and methylationcheck homocysteine levels; if they are high, it may indicate poor methylation and raised risk of cognitive decline.
  • Tyrosine – dopamine is made from this amino acid. A supplement of 500mg twice daily can help support dopamine production.

Protein + slow carbs – pairing protein (such as nuts or Greek yogurt) with fruit like berries slows sugar release and provides fibre and nutrients.

If you feel like you are struggling to break free from food addiction, then join  Dr Jen Unwin’s live webinar on Wednesday, 24th September – find out more here.

 A clinical Psychologist’s Practical Tips on How to break free; 

  • Visualise how life will improve once you manage to quit your “drug foods”. These are typically ultra-processed and sugary foods with which you’re unlikely to have a healthy relationship.
  • Have an honest conversation with friends and family about the foods you struggle with, and ask for their support in resisting them..
  • Removing the “drug foods” from your home and diet is key. Replace them with natural, whole foods.
  • Give it time. Every day you resist, it gets easier. “Those foods are no longer in my thoughts at all,” says Dr Unwin.
  • If you take medication for diabetes or high blood pressure, consult your GPbefore reducing sugar and carbohydrates in your diet, as your dosage may need adjusting.
  • If you’re concerned about food addiction or would like to learn more, Dr Unwin recommends joining a Public Health Collaboration (PHC) support group in the UK, or Sweet Sobriety in the US. The PHC also runs a virtual lifestyle support group every Monday at 6pm, where you can learn more about overcoming food addiction and maintaining good metabolic health.

The Bigger Picture

Food addiction is more than a personal struggle and it impacts more people than you realise. It’s part of a wider public health crisis, fuelling obesity, diabetes and dementia – but no matter where you are at right now, change is possible!

Ways to get support:

Food or drink addiction? Discover how to beat cravings and food addiction in Dr Jen Unwin’s live webinar, 24 Sept.

Join the live webinar on food addiction with clinical psychologist Dr Jen Unwin on Wednesday, 24th September – find out more here.

International Food Addiction & Comorbidities Conference logo

ttend the International Food Addiction & Comorbidities Conference – IFACC 2025. Use discount code FFB to get 40% off:

  • Two-day in-person ticket: £150 (full price £250)
  • Two-day livestream ticket: £54 (full price £90)

Cognition Programme logo

Get ongoing support with the COGNITION™ programme. Receive monthly coaching when you become a. FRIEND of Food for the Brain.

Fork in a road logo

Read Dr Jen Unwin’s book, Fork in the Road a hopeful guide for identifying if you have a food addiction and learning what to do about it.

frontiers logo

Read this journal article in Frontiers in Psychiatry to support and join the movement to have food addiction classified as a real disease, thus enabling more research and support, and helping to make the dangers of ultra-processed foods more visible.

Further info

Snacks: Brain Boost or Brain Drain?

Colourful selection of snacks displayed on a flat surface

When that mid-morning dip or afternoon slump hits, it’s tempting to reach for a quick fix – something sweet, something carby, something to perk you up. But most conventional snacks don’t fuel your brain – they drain it.

In fact, snacking is one of the easiest ways to sabotage your long-term brain health and memory. Most people wouldn’t eat a plate of sugar at mealtimes (unless they start the day with shop-bought cereal or sweetened yoghurt), yet it’s common to reach for a bar, a biscuit, or something from a petrol station or coffee shop without a second thought.

These everyday choices are a silent driver of brain fog, low mood, memory problems – even dementia. It’s time to upgrade your brain by upgrading your snacks. Below, we share a free Brain Boost Bites recipe and some other smart snack ideas – perfect for long drives, picnics, or busy days on the go.

The Problem with Typical Snacks

The modern snack aisle is a minefield of ultra-processed foods: cereal bars, crisps, flavoured yoghurts, granola bites, and biscuits – many of them marketed as “healthy”. But beneath the surface, they’re often:

  • High in sugar or refined carbs – causing a rapid blood glucose spike followed by a crash. Many so-called healthy bars contain over 15g of sugar with little fibre, protein, or healthy fat to balance them.
  • Low in brain-essential nutrients – such as omega-3s, magnesium, or phospholipids.
  • Full of artificial additives – emulsifiers, preservatives, and even excitotoxins like MSG.
  • Designed for instant gratification – often with addictive properties rather than sustained energy.

As explained in our Four Horsemen of the Mental Health Apocalypse series (read Part 1 here and Part 2 here), poor glucose control is a key driver of accelerated brain ageing and cognitive decline. A high-sugar snack spikes blood sugar, then causes a crash that reduces brain energy and impairs mental performance. Over time, this rollercoaster leads to insulin resistance, which is strongly linked to cognitive decline and Alzheimer’s disease.

The Smart Snacking Solution

The answer isn’t to stop snacking altogether – it’s to snack smart.

Our in-house chef and lecturer in culinary nutrition and functional health, Kim Close, shares a free recipe below from the Upgrade Your Brain Cook App. It’s packed with brain-supportive nutrients and perfect for keeping your energy and focus steady.

And if you’re not sure what to eat for better brain health, the Cook App includes 120+ recipes (and growing) to guide you meal by meal.

Brain Boost Bites

Refined sugar-free | Fibre-rich | Brain-fat fuelled | Brain Boosting

Brain Boosting snacks - bite balls in a plate

Ingredients:

  • 100g (3½ oz) almonds
  • 30g (1 oz) walnuts
  • 50g (1¾ oz) goji berries
  • 2 tbsp ground flaxseed
  • 2 tbsp almond butter
  • 1 tbsp raw cacao powder
  • 1 tbsp water (if needed for blending)

Method:

  1. Blend all ingredients in a food processor until the mixture becomes sticky and holds together.
  2. Roll into small balls.
  3. Chill in the fridge for at least 30 minutes.

Servings: Makes 10-12 balls

Cook’s Tips: Store in an airtight container in the fridge for up to a week. Add orange zest or vanilla extract for flavour variation.

Other Smart Snack Ideas:

  • Oatcakes with almond butter or smoked mackerel pâté
  • Olives 
  • Square of Dark Chocolate Bar (Recipe in Cook App)
  • Hummus or nut butter with raw veggie sticks
  • A boiled egg with cherry tomatoes
  • A handful of walnuts or pumpkin seeds
  • A small cup of full-fat Greek yoghurt with blueberries
  • Chia pudding made with coconut milk (recipe in the app)
  • 2 squares of 85%+ dark chocolate

Snacking wisely is one of the easiest daily upgrades you can make for your brain. And with the right ingredients, it can be delicious too.

Further info

The Mood & Brain Boost: 7 Ways to Ditch the Seasonal Slump

How can we lift our mood and nourish our brain? 

Depression, now the leading cause of disability globally, affects millions. According to the World Health Organization, it represents a significant disease burden, particularly in high-income countries (1). With a staggering 100 million antidepressant prescriptions issued annually—a 70% increase in five years—it’s clear that something is going wrong in our modern western world (1).

Thankfully, nutrition and lifestyle changes provide science-backed ways to boost our mood naturally.

(If you want to know more about how to overcome depression then make sure you watch our webinar ‘Finding your way out of depression’).

Understanding Depression

Depression manifests through persistent feelings of hopelessness, low energy, disrupted sleep, and even physical changes such as weight loss or gain (2). The root causes can be multifactorial—psychological stress, biochemical imbalances, or nutritional deficiencies.

But here’s the good news: you can take simple, practical steps to nourish your brain, boost serotonin, and improve your mood naturally.

7 Ways to Boost Mood and Brain Function
1. Increase Your Omega-3 Fats

Your brain is 60% fat, and omega-3 DHA and EPA are critical for its structure and function. Countries with high fish consumption have lower depression rates. A study from Harvard Medical School found that EPA, specifically, has potent antidepressant effects.

A meta-analysis published in Psychopharmacology Bulletin found that higher omega-3 intake reduces depressive symptoms by 53%. Omega-3 helps build brain cell membranes and boosts serotonin receptor function, which improves mood and cognition.

  • What to do: Eat oily fish like salmon, sardines, and mackerel at least twice a week or supplement with high-dose omega-3 fish oil. Aim for 1,000–2,000 mg of EPA and DHA combined daily (4, 5, 6).

2. Optimise Your B Vitamins and Lower Homocysteine

The little-known amino acid, homocysteine, may double your risk for depression if levels are elevated. This toxic by-product accumulates when you’re deficient in B6, B12, and folic acid, impairing brain chemistry. 

Studies by Professor David Smith from Oxford show that lowering homocysteine can dramatically slow brain shrinkage and improve mood. Which is why we now offer at home homocysteine test kits so you can monitor your own level and prevent disease (7,8,9).

  • What to do: Eat leafy greens, whole grains, and fortified foods. Test your homocysteine and aim for levels below 7 μmol/L. Supplement with a methylated B complex (20 mg B6, 500 μg B12, and 400 μg methylfolate).

“B vitamins are brain-makers; without them, key neurotransmitters like serotonin can’t be synthesised” – Patrick Holford, Upgrade Your Brain.

3. Fuel Your Brain with Serotonin Precursors

Serotonin, your “happy hormone”, is made from tryptophan, an amino acid found in protein-rich foods like fish, poultry, beans, and eggs. For some, tryptophan conversion to serotonin is impaired due to poor digestion or low stomach acid, common with age and stress.

Supplementing with 5-HTP can bypass these barriers. Clinical studies show 5-HTP compares favourably with SSRIs in treating depression (10, 11, 12, 13).

  • What to do: Include tryptophan-rich foods daily and consider a 5-HTP supplement (100–200 mg twice daily). Always consult your doctor if combining with antidepressants.
4. Balance Your Blood Sugar

Maintaining stable blood sugar levels is essential for mood regulation, as uneven glucose supply to the brain can lead to irritability, fatigue, and depressive symptoms. Diets high in refined carbohydrates and sugar contribute to these fluctuations and are linked to poor mood and an increased risk of depression. A study of 3,456 adults found that individuals consuming diets rich in processed foods had a 58% greater risk of depression, whereas those eating whole foods experienced a 26% reduced risk (14, 14, 16).

 Refined sugars also deplete mood-enhancing nutrients like B vitamins, essential for energy production, and divert chromium, which is vital for glucose regulation. Adopting a low glycaemic load (GL) diet, avoiding caffeine and alcohol, and focusing on whole foods, fruits, and vegetables can help stabilise blood sugar levels and improve mood.

  • What to do: Follow a Low-GL diet with whole foods, low-GL carbs, and protein at every meal. Avoid sugar, caffeine, and alcohol .

5. Boost Your Vitamin D Levels

The “sunshine vitamin,” vitamin D, is essential for mood regulation. Research shows a 40% lower incidence of depression in those with adequate vitamin D. Alarmingly, over 60% of the UK population is deficient during winter (17, 18, 19, 20).

  • What to do: Get tested and aim for levels above 75 nmol/L. Supplement with 2,000–3,000 IU daily in winter months.

6. Include Chromium to Combat Atypical Depression

If you suffer from atypical depression—characterised by weight gain, fatigue, and carbohydrate cravings—you might benefit from chromium. Studies show chromium supplementation can improve mood scores by up to 83% (21, 22, 23).

  • What to do: Include whole grains and vegetables or supplement with 600 mcg of chromium picolinate daily.

7. Bring on the Sunshine and Movement

Exercise and sunlight have a direct effect on serotonin levels and mood. Regular exercise boosts brain-derived neurotrophic factor (BDNF), which helps build new brain cells and connections】.

  • What to do: Aim for 30 minutes of exercise daily and sun exposure for 15 minutes, when safe.
Key Action Plan
  1. Eat oily fish twice weekly or supplement omega-3s with at least 1,000 mg EPA and DHA.
  2. Test and lower homocysteine with B6, B12, and folic acid supplements.
  3. Try 5-HTP to boost serotonin naturally.
  4. Follow a Low-GL diet to stabilise blood sugar.
  5. Supplement vitamin D during winter. Find out more about dose here.
  6. Add chromium for atypical depression.
  7. Exercise regularly and get sensible sun exposure.

 References

  1. World Health Organization. Depression and Other Common Mental Disorders: Global Health Estimates. WHO; 2017.
  2. Brown G, et al. Social support, self-esteem and depression. Psychol Med. 1986;16(4):813-31.
  3. Hibbeln JR. ‘Fish consumption and major depression’. Lancet, vol 351(9110), pp. 1213 (1998)
  4. M. Peet and R, Stokes, Omega 3 Fatty Acids in the Treatment of Psychiatric Disorders Drugs, vol 65(8), pp. 1051-9 (2005)
  5. S Kraguljac NV, Montori VM, Pavuluri M, Chai HS, Wilson BS, Unal SS (2009) Efficacy of omega-3 Fatty acids in mood disorders – a systematic review and metaanalysis. Psychopharmacology Bulletin 42(3):39-54
  6. Hibbeln JR. Fish consumption and major depression. Lancet. 1998;351(9110):1213.
  7. Coppen A, Bailey J. Folic acid and affective disorders. J Affect Disord. 2000;60(2):121-30.
  8. Taylor MJ, Carney SM, Goodwin GM, Geddes JR. Folate for depressive disorders. Cochrane Database Syst Rev. 2003;(2):CD003390.
  9. Smith AD, Refsum H. Homocysteine, B vitamins, and cognitive impairment. Annu Rev Nutr. 2016;36:211-39.
  10. Poldinger W et al. A comparison of 5-hydroxytryptophan and fluvoxamine. Psychopathology. 1991;24(2):53-81.
  11. E. Turner, Serotoninalacarte: Supplementation with the serotonin precursor 5-hydroxytryptophan.’ Pharmacology&Therapeutics (2005) [article in press].
  12. W. Poldinger et al. A functional-dimensional approach to depression: serotonin deficiency and target syndrome in a comparison of 5-hydroxytryptophan and fluvoxamine, Psychopathology vol 24(2), pp. 53-81 (1991)
  13. Associate editor: K.A. Neve ‘Serotonin a la carte: Supplementation with the serotonin precursor 5-hydroxytryptophan’ ErickH. Turner a,c,d,*, Jennifer M. Loftis a,b,c, AaronD. Blackwell a,b,e Pharmacology & Therapeutics(2005) www.elsevier.com/locate/pharmthera
  14. Akbaraly TN, Brunner EJ, Ferrie JE, et al. Dietary pattern and depressive symptoms in middle age. Br J Psychiatry. 2009;195:408–13.
  15. Benton D, Owens DS, Parker PY. Blood glucose influences memory and mood in an everyday setting. Biol Psychol. 1982;14(1-2):129–35.
  16. Christensen L. Psychological distress and diet – effects of sucrose and caffeine. J Appl Nutr. 1988;40(1):44–50.
  17. Lansdowne AT, Provost SC (1998): Demonstrates that vitamin D3 supplementation enhances mood in healthy subjects during winter.
  18. C. Wilkins et al. (2006): Links vitamin D deficiency to low mood and poorer cognitive performance in older adults.
  19. A. Nanri et al. (2009): Discusses the association between vitamin D levels and depressive symptoms across seasonal changes.
  20. R. Jorde et al. (2008): Shows that vitamin D supplementation alleviates depressive symptoms in overweight and obese individuals
  21. Lifting Depression – The Chromium Connection by Dr Malcolm McLeod (Basic Health Publications):
  22. J. R. Davidson et al, Effectiveness of chromium in atypical depression: a placebo-controlled trial, Biol Psychiatry, vol 53(3), pp. 261-4 (2003)
  23. Docherty, J et al, ‘A Double-Blind, Placebo-Controlled, Exploratory Trial of Chromium Picolinate in Atypical Depression’. Journal of Psychiatric Practice. Vol 11(5), pp. 302-314, (2005)
  24. Holford P. Upgrade Your Brain. HarperCollins; 2024.
Further info

The Four Horsemen of the Mental Health Apocalypse #2 – Brain Fuel & Antioxidants

By Patrick Holford

Few people realise the catastrophic decline in mental health that has occurred over the past 50 years.

‘Brain health conditions have become a global health emergency,’ according to the Federation of European Neuroscience Societies last year (1).

The big question is: why?

Introducing the four horsemen (recap)

I’m proposing that there are four main biological drivers of our demise which I’m calling the four horsemen of the mental health apocalypse: a lack of brain fats, messed up methylation, loss of glucose control and excessive oxidation.

The first two – brain fats and methylation – are vital for the integral structure of neuronal membranes.

The second two are vital for the function of brain cells, supplying fuel and coping with the oxidant ‘exhaust fumes’ of energy metabolism.

Brain fuel

While omega-3 and B vitamins literally build a healthy brain, it is glucose and ketones that fuel it.

As a result of this process, oxidants are created which age the brain through the process of oxidation. Of course, oxidation can also occur through external causes, which is why smoking and air pollution are also established risk factors for Alzheimer’s.

Which leads us to the next two ‘horses of the mental health apocalypse’: the brain’s fuel supply and antioxidant protection. The brain consumes more energy than any other organ of the body. Neurons can only run on glucose or ketones. The irony is that the consequence of eating too many carbs and sugar is that the brain develops insulin resistance – effectively blocking the glucose from entering the mitochondria within the neurons. Starved of their energy source, we experience the consequences as mental fatigue and forgetfulness. According to Dr Robert Lustig,  Emeritus Professor of Pediatrics at the University of California, San Francisco and a member of our Scientific Advisory Board, “This cognitive decline starts young. Cognitive decline in overweight children is associated with a high GL diet (1), and adolescents with metabolic dysfunction, driven by a high GL diet, have been shown to have shrinkage of the hippocampal area of the brain, as well as other structural changes and cognitive deficits (2).” This particular study showed actual shrinkage of the Alzheimer’s associated area of the brain in teenagers with metabolic syndrome as a consequence of too much sugar and ‘white’ carbs. The youngest age of an Alzheimer’s diagnosis, which requires proof of shrinkage of the hippocampal area of the brain, is age 19, in a young man in China who had no genetic risk factors (2).

It’s a biochemical storm.

As well as the fuel starvation that insulin resistance generates, the converse of blood sugar spikes, create Advanced Glycation End-products, or AGEs, that literally damage neurons. This ‘glycosylation’ is also seen in red blood cells, and why the HbA1c test which measures glycosylated haemoglobin is so good at predicting our health. If over 6.5% (or 48 mmol/mol) of these erythrocytes are sugar damaged, it’s a clear basis for a diabetes diagnosis. Just as for the omega-3 index, HbA1c is a reliable long-term measure showing the average sugar spikes over the past three months. You can assume what’s happening in the membranes of red blood cells is also happening to the neuronal membranes in the brain. 

This is why the next brain essential is to measure HbA1c.

If 6.5% is the cut-off for a diabetes diagnosis, the ideal level is actually considerably lower. In what is usually considered to be the ‘normal range’, teenagers with HbA1c above 5.4% show cognitive decline and shrinkage of the hippocampus in the central area of the brain compared to those with lower HbA1c levels (3). “In teenagers with raised, but normal levels of HbA1c, there is clear evidence of the same kind of memory problems, and the same areas of brain shrinkage seen in patients with Alzheimer’s Disease” says Dr Robert Lustig.

Shrinkage of the hippocampus is the hallmark of Alzheimer’s and is used to diagnose the disease. A new study shows that 40-year-old adults with so-called normal glucose levels, but at the higher end of the normal range, have increased their risk of Alzheimer’s by 15%. (4) 

A primary function of sleep is to repair all the neuronal membrane damage that occurs during the day. No sleep, no repair and the brain ages fast. This is mainly why lack of sleep is also a strong risk factor for Alzheimer’s.

Do ketones fill the energy gap?

There’s a growing interest in the role of ketogenic diets and ketone promoting supplements for brain health. Professor Stephen Cunnane, our expert in the new science of ‘keto therapeutics’ has shown that giving C8 oil or supplementing ketones can help to prevent Alzheimer’s, slow down cognitive decline, improve mood and lessen anxiety. His studies showed, in those with mild cognitive impairment, that taking 30g (two tablespoons) of mainly C8 oil, resulted in a 230% increased brain energy production from ketones with no change in energy derived from glucose (5), thus filling the ‘energy gap’ so often experienced by older people or those drifting towards insulin resistance. “Our research shows that the areas of the brain that have trouble using glucose for energy are able to use ketones perfectly well, even in moderately advanced dementia. This may explain why many people later in life who are given a supplement of C8 oil or MCT oil have improvements on a battery of cognitive tests. They often feel it brings their brain power back to life” says Cunnane. 

Many people also report feeling calmer, less anxious and less depressed on ketogenic diets. A new book, Change Your Diet, Change Your Mind, out next month by psychiatrist Dr Georgia Ede digs deep into the growing evidence that a ketogenic diet, or at least one low in carbohydrates, is brain-friendly and helps people out of various mental health disorders. Or you can watch the recent webinar she did with us here.

Antioxidant and polyphenol power

The more biologically active an essential fat is (with DHA at the top), the more prone it is to oxidation.

It is literally this ability of DHA to absorb energy (photons from light) that creates the impulse that passes information from the eye to the brain. It explains the origin of the brain and nervous system, going back a billion years to a rudimentary single cell called dynoflagellate. This little organism basically used the electric shock from photons to create the first ‘twitch’ towards light. Where there was light, there was food, and ultimately the evolution of the nervous system and brain. In simple terms, we can see that the brain is really an extension of the eye. How do we see with such precision and speed? Until now, no-one has been able to explain this satisfactorily. At the age of 93, Professor Michael Crawford, who helped our charity get started, has worked out how this occurs and how we see in colour. It requires knowledge of quantum physics, explained in a recent paper entitled ‘Docosahexaenoic Acid Explains the Unexplained in Visual Transduction’.(6)

With all this volatile fatty acid and mitochondrial energy production, cleaning up the oxidant exhaust fumes is a vital function for a healthy brain. So how do we achieve protection and how do we measure it?

There are hundreds, if not thousands of antioxidants and polyphenols in our food. Foods can be measured for their ‘Total Antioxidant Capacity’ or TAC for short. It’s worked out from an equation involving eight key antioxidants from vitamin A, carotenes (think carrots), lycopenes (rich in tomatoes), lutein and zeaxanthine (rich in green vegetables), vitamin E (in nuts and seeds), but most of all vitamin C (rich in berries, broccoli, peppers and other vegetables).

Vitamin C is a keystone nutrient as far as swinging the antioxidant equation in our favour. Individually, the impact of these nutrients on our health may be less than when combined. For example, a study of 4,740 Cache County Utah elderly residents found that those supplementing both vitamin E and C cut their risk of developing Alzheimer’s by two thirds (66%). Taking just one cut the risk by a mere quarter (25%).  (7)

The higher the TAC score of our diet, the lower our risk of memory decline becomes. This was the finding of a recent study of 2,716 people over age 60. Higher TAC scores correlated with better memory function (8). Those in the highest quarter of TAC scores had half the risk of decreasing memory. Powerful stuff!

Tea, cacao, red wine, red onions, olives and berries are rich sources of polyphenols. Many of these polyphenol-rich foods improve circulation, lower blood pressure and dampen down inflammation which lies behind many brain and heart health problems. 

More than a decade ago research in Norway (9) found that the more tea you drink the better; a small glass of wine (125ml) a day (preferably red, as it is rich in resveratrol) reduces the risk of cognitive decline. Cacao is also beneficial, ideally no more than 10g, (about 3 pieces) of dark, 70 percent or more. Other studies based on adding cacao to the diet have shown improved cognition, possibly by improving circulation. This was recently confirmed in a big ‘COSMOS’ trial involving over 20,000 people given a cacao extract supplement versus a placebo for five years (10). The reduction in cardiovascular risk was even greater than that of a Mediterranean diet.

The take-away message? Polyphenols are a vital part of a healthy diet for both our heart and our brain.

So, what do we need to eat and drink to protect our brain and body? Basically, eat a Mediterranean-style ‘rainbow coloured’ diet. A Mediterranean diet has more fish, less meat and dairy, more olive oil, fruit and vegetables including tomatoes, legumes (beans and lentils), and whole grain cereals than a standard Western diet. It also includes small quantities of red wine. There are variations of this kind of diet, called the MIND diet and the DASH diet, but the core components are the same. As researchers drill down, we are learning what to eat and drink and how much, to keep our minds sharp and brain young.

The trick is to really start thinking of the colours we are eating and gravitate to the strong colours, choosing organic where possible. Mustard and turmeric, for example, are strong yellows. Bright oranges include butternut squash, sweet potato, carrots. For red, think tomatoes and watermelons. Anything purple, magenta or blue is brilliant for us too. From beetroots (eat them raw, grated into salads) to blueberries, blackberries to raspberries, all these foods are fantastically good for us, so tuck in!

In addition to food, as a health aspiring 65-year-old, I both supplement 1 gram of vitamin C twice a day and take an AGE Antioxidant containing Co-Q10, alpha lipoic acid, n-acetyl cysteine (NAC – as a precursor to glutathione which is the master antioxidant) and resveratrol as well as vitamin E and A – both beta-carotene and retinol. Many people think that there is no point supplementing glutathione because it is so rapidly oxidised, or sacrificed, to disarm oxidants, but it is also rapidly recycled by anthocyanidins in blue/red berries. So, combining the two reloads glutathione. This film shows how.

But how do we measure our antioxidant status?

My research team is working on exactly this challenge and we are finding that the ratio between reduced glutathione (GSH) and oxidised glutathione (GSSG) in red blood cells is probably the best biological determinant. We hope to introduce that into our panel of functional indicators, and research how it correlates with dietary intake and lifestyle habits as well as cognitive function.

We are due to launch a DRIfT Test as part of a global prevention initiative, which will be a 4 in 1 test

The UK Biobank has collected data on 500,000 people since 2006, inviting people to fill in questionnaires, give blood and carry out certain tests. We are funded by ‘Friends’ who pay £50/$60/€60 a year.  So far we have collected data on 410,000 people and this number is growing by about a hundred a day. 

In addition to taking the blood test, participants are invited to complete a validated online Cognitive Function Test (not a questionnaire), followed by a comprehensive 144 question Dementia Risk Index diet and lifestyle questionnaire which takes 20-25 minutes. This works out a person’s future risk and shows what’s driving the risk. This is a free service.

We run the UK’s leading dementia prevention charity which is running the prevention project together with Dr Tommy Wood, Assistant Professor at the University of Washington. “By tracking a person’s blood sugar, vitamin B, D and omega-3 status against changes in cognitive function over time, in addition to lifestyle factors such as sleep and physical activity, we can learn what really helps prevent cognitive decline.” says Dr Wood, the principal investigator for the study. 

Test Your Cognitive Function Now green banner.
Citizen Science

All donations are put back into research, and the results of the research are shared back to the people. 

This is science for the people, funded by the people, shared back with the people. We call them Citizen Scientists and we hope to reach a million people around the world within a year or so making this the biggest prevention-focussed study of its kind. The purpose of research is to help people. Too often great scientists do great studies, which get published and ignored. We have to face the fact that, in the UK as an example, the Government has commissioned four reports on mental health and Wellcome did a further independent report, all showing we have a cerebral tsunami with brain and mental health disorders ahead of every other disease.

They have ignored every single one.

Change is not going to come from the Government or the NHS. It is going to have to come from us, the people. I urge everyone in natural medicine to take the test themselves, share it with others and support us by becoming Friends and donating £50 a year, getting so much in return.

This is how we are funding our amazing research team. We are a lean, keen, small but mighty team. 

Every donation, big or small, goes right back into helping people prevent these preventable and terrible diseases such as dementia. 

Together, we can change the world. 

We need to because time is running out. 

We will lose our humanity if we don’t stop this brain drain.

Want to learn more about homocysteine and how to reclaim your brain? Join us for the Homocysteine Unplugged webinar.

References

1 Lakhan, S.E., Kirchgessner, A. The emerging role of dietary fructose in obesity and cognitive decline. Nutr J 12, 114 (2013). 

3 Yau PL, Castro MG, Tagani A, Tsui WH, Convit A. Obesity and metabolic syndrome and functional and structural brain impairments in adolescence. 

Pediatrics. 2012 Oct;130(4):e856-64. doi: 10.1542/peds.2012-0324. Epub 2012 Sep 

4  Zhang X, et al Midlife lipid and glucose levels are associated with Alzheimer’s disease. Alzheimers Dement. 2023

5  Fortier M, Castellano CA, St-Pierre V, Myette-Côté É, Langlois F, Roy M, Morin MC, Bocti C, Fulop T, Godin JP, Delannoy C, Cuenoud B, Cunnane SC. A ketogenic drink improves cognition in mild cognitive impairment: Results of a 6-month RCT. Alzheimers Dement. 2021 Mar;17(3):543-552. doi: 10.1002/alz.12206. Epub 2020 Oct 26. PMID: 33103819; PMCID: PMC8048678.

6 Crawford, M.A..; Sinclair, A.J.; Wang, Y.;
Schmidt, W.F.; Broadhurst, C.L.; Dyall, S.C.; Horn, L.; Brenna, J.T.; Johnson, M.R.; Docosahexaenoic Acid Explains the Unexplained in Visual Transduction. Entropy 2023, 25, x. https://doi.org/10.3390/xxxxx 

7  Basambombo LL, Carmichael PH, Côté S, Laurin D. Use of Vitamin E and C Supplements for the Prevention of Cognitive Decline. Ann Pharmacother. 2017 Feb;51(2):118-124. doi: 10.1177/1060028016673072. Epub 2016 Oct 5. PMID: 27708183.

8 Peng, M., Liu, Y., Jia, X. et al. Dietary Total Antioxidant Capacity and Cognitive Function in Older Adults in the United States: The NHANES 2011–2014. J Nutr Health Aging 27, 479–486 (2023). https://doi.org/10.1007/s12603-023-1934-9

9 Nurk E, Refsum H, Drevon CA, Tell GS, Nygaard HA, Engedal K, Smith AD. Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance. J Nutr. 2009 Jan;139(1):120-7. doi: 10.3945/jn.108.095182. Epub 2008 Dec 3. PMID: 19056649.

10 Sesso HD, Manson JE, Aragaki AK, Rist PM, Johnson LG, Friedenberg G, Copeland T, Clar A, Mora S, Moorthy MV, Sarkissian A, Carrick WR, Anderson GL; COSMOS Research Group. Effect of cocoa flavanol supplementation for the prevention of cardiovascular disease events: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial. Am J Clin Nutr. 2022 Jun 7;115(6):1490-1500. doi: 10.1093/ajcn/nqac055. PMID: 35294962; PMCID: PMC9170467.

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Sleep, Stress and the Brain: Why Quality Rest Matters

By Patrick Holford

What does any animal, perhaps your dog, do after exercising or going for a walk?

Sleep.

Sleep is how the brain recovers. There is now overwhelming evidence that sleep is a ‘brain essential’ and just like Goldilocks, it seems we need just the right amount. Getting too much, or too little, increases our risk for cognitive decline.

The optimal amount of sleep for brain health appears to be a total of seven hours. This does not necessarily need to be in one uninterrupted stretch – a study found that napping after physical activity can reduce the risk of cognitive impairment (1).

However, those consistently getting less than seven hours of sleep may be doubling their risk of age-related cognitive decline (2). A UK study of Whitehall civil servants, which began in the 1980s, found that persistent short sleep at ages 50, 60, and 70 was associated with a 30% increased risk of dementia (3). Sleep loss does not just increase long-term dementia risk – it also reduces empathy, increases negative emotions, and impairs next-day functioning (4).

Why Sleep Is Essential to Brain Health?

Think of sleep as the brain’s housekeeper. During sleep, circulation of blood and cerebrospinal fluid improves, helping to clear out waste products from brain metabolism (5). These include harmful oxidants and amyloid protein, the latter linked to Alzheimer’s and brain inflammation – which can begin accumulating after just one night of poor sleep (6).

One key agent in this nightly brain cleanse is melatonin. As night falls, our brains convert serotonin into melatonin, primarily in the pineal gland – referred to by Descartes as the seat of the soul, and known in yoga as the ‘third eye’ chakra.

Sensitive to light via receptors behind the eyes, the pineal gland is the only endocrine organ in direct contact with the external world. Darkness triggers melatonin production, while exposure to light – including screen use before bed – suppresses it.


Melatonin helps keep us in sync with the circadian cycle. Some frequent flyers even use melatonin supplements to overcome jet lag and adjust their sleep rhythms more easily (7).

More than just a sleep aid, melatonin acts as a powerful antioxidant – disarming damaging oxidants, restoring mitochondrial energy production, and acting as an anti-inflammatory. It has been used to support recovery in cancer, COVID-19, and cardiovascular conditions (8,9). Reduced brain melatonin levels and circadian disruption are also observed in individuals with cognitive decline.

Why Dreaming Matters?

Sleep isn’t just for rest – it’s a deeply active process. About 30 minutes after falling asleep, we enter deep sleep, marked by slower breathing, a reduced heart rate, and lower blood pressure. This phase restores and repairs bodily tissues. About 90 minutes in, we shift into REM (rapid eye movement) sleep – where most dreaming occurs.

REM sleep is critical for brain health. Each night, we cycle between deep, light, and REM sleep three to five times, with REM ideally making up about 25% of total sleep.

REM and deep sleep phases also see increased production of growth hormone, which supports tissue repair. Meanwhile, melatonin helps clear metabolic waste. However, under stress, cortisol levels rise and suppress REM sleep and growth hormone production, reducing the brain’s ability to recover. Sleep-deprived individuals tend to experience more REM when they finally do sleep, suggesting REM plays a key role in emotional processing.

One theory suggests that dreams help us metabolise suppressed emotions – fear, anger, sadness – stored during our busy days. If you have a vivid, emotional dream, it may be worth tracing it back to unresolved feelings from the previous day.

How Chronic Stress Disrupts Sleep and Brain Function?

Chronic or intense stress – such as bereavement, illness, or financial strain – has been shown to increase the risk of cognitive decline and dementia (10). However, good sleep can help process a stressful day.

The perception of control matters, too. Studies show that high job demands combined with low control are strongly linked to an increased risk of depression and cognitive impairment (11). Examples might include caregiving for a loved one with dementia while navigating health services, or working in a high-stress job without the resources to make meaningful changes.

Your Brain on Cortisol: The Hippocampus Feedback Loop

Two hormones mediate stress: adrenaline (short-acting) and cortisol (longer-acting). Adrenaline prepares you to act quickly – it’s the fight-or-flight hormone. Cortisol helps regulate energy and alertness throughout the day.

In the morning, cortisol naturally rises to get us going. It should fall in the evening to support sleep. But chronic stress disrupts this rhythm. If cortisol stays high at night, sleep is disturbed. If it’s too low in the morning, you may feel foggy and reach for caffeine.

Excess cortisol impairs memory, slows thinking, lowers social functioning, and raises the risk of dementia (12). What’s happening in the brain is that cortisol overstimulates the hippocampus, which is responsible for memory and emotional regulation. With prolonged stress, this feedback loop fails – the hippocampus shrinks, and cortisol levels remain elevated, accelerating brain ageing.

Short-Term Relief, Long-Term Harm: Sugar and Alcohol as Stress Crutches

Oscar Ichazo described how we reach for compensations under stress. Unfortunately, many – like alcohol and sugar – backfire.

Alcohol temporarily boosts GABA, calming the nervous system and reducing adrenaline. But the effect is short-lived. Drinking too much reduces GABA receptor sensitivity the next day, leaving us more anxious. In the long term, alcohol is neurotoxic and increases dementia risk (12). It also disrupts sleep architecture, impairing the brain’s ability to repair itself.

Sugar triggers dopamine and activates the brain’s reward circuits, making us crave more. It also spikes the adrenal system, amplifying stress and cortisol levels (13). Fats and proteins do not have this effect – this is unique to sugar.

So, when we use sugar or alcohol to manage stress, we often wake up feeling more anxious and foggy. This leads us to reach for caffeine and more sugar, which spikes cortisol again, leaving us even more depleted by evening – creating a cycle of stress, poor sleep, and accelerated brain ageing.

Simple Ways to Break the Cycle

The good news? You can reverse this pattern. Start here:

  • Become a FRIEND and get access to your personalised COGNITION® programme which which includes:
    – A whole module dedicated to sleep and calm
    – Another focused on helping you reduce sugar
    – Plus monthly live group coaching to help you stay focused and on track
  • Prioritise seven hours of quality sleep each night.
  • Identify and reduce common stress triggers.
  • Be mindful of alcohol and sugar intake.
  • Find positive outlets: yoga, walking, journaling, a good book – like Upgrade Your Brain.

Thank you for reading!
Food for the Brain is a non-for-profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index to be able to advise you on how to dementia-proof your diet and lifestyle.

By completing the Cognitive Function Test you are joining our grassroots research initiative to find out what really works for preventing cognitive decline. We share our ongoing research results with you to help you make brain-friendly choices.

Please support our research by becoming a Friend of Food for the Brain.

———

References:

1 Qian YX, Ma QH, Sun HP, Xu Y, Pan CW. Combined effect of three common lifestyle factors on cognitive impairment among older Chinese adults: a community-based, cross-sectional survey. Psychogeriatrics. 2020 Nov;20(6):844-849. doi: 10.1111/psyg.12604. Epub 2020 Aug 31. PMID: 32869429.

2 Bubu OM, Brannick M, Mortimer J, Umasabor-Bubu O, Sebastião YV, Wen Y, Schwartz S, Borenstein AR, Wu Y, Morgan D, Anderson WM. Sleep, Cognitive impairment, and Alzheimer’s disease: A Systematic Review and Meta-Analysis. Sleep. 2017 Jan 1;40(1). doi: 10.1093/sleep/zsw032. PMID: 28364458.

3 Sabia S, Fayosse A, Dumurgier J, van Hees VT, Paquet C, Sommerlad A, Kivimäki M, Dugravot A, Singh-Manoux A. Association of sleep duration in middle and old age with incidence of dementia. Nat Commun. 2021 Apr 20;12(1):2289. doi: 10.1038/s41467-021-22354-2. PMID: 33879784; PMCID: PMC8058039.

4 Krause AJ, Simon EB, Mander BA, Greer SM, Saletin JM, Goldstein-Piekarski AN, Walker MP. The sleep-deprived human brain. Nat Rev Neurosci. 2017 Jul;18(7):404-418. doi: 10.1038/nrn.2017.55. Epub 2017 May 18. PMID: 28515433; PMCID: PMC6143346.

56 Xie L, Kang H, Xu Q, Chen MJ, Liao Y, Thiyagarajan M, O’Donnell J, Christensen DJ, Nicholson C, Iliff JJ, Takano T, Deane R, Nedergaard M. Sleep drives metabolite clearance from the adult brain. Science. 2013 Oct 18;342(6156):373-7. doi: 10.1126/science.1241224. PMID: 24136970; PMCID: PMC3880190.

6 Shokri-Kojori E, Wang GJ, Wiers CE, Demiral SB, Guo M, Kim SW, Lindgren E, Ramirez V, Zehra A, Freeman C, Miller G, Manza P, Srivastava T, De Santi S, Tomasi D, Benveniste H, Volkow ND. β-Amyloid accumulation in the human brain after one night of sleep deprivation. Proc Natl Acad Sci U S A. 2018 Apr 24;115(17):4483-4488. doi: 10.1073/pnas.1721694115. Epub 2018 Apr 9. PMID: 29632177; PMCID: PMC5924922.

7 Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev. 2002;(2):CD001520. doi: 10.1002/14651858.CD001520. PMID: 12076414.

8 Keithahn C, Lerchl A. 5-hydroxytryptophan is a more potent in vitro hydroxyl radical scavenger than melatonin or vitamin C. J Pineal Res. 2005 Jan;38(1):62-6. doi: 10.1111/j.1600-079X.2004.00177.x. PMID: 15617538.

9 Chitimus DM, Popescu MR, Voiculescu SE, Panaitescu AM, Pavel B, Zagrean L, Zagrean AM. Melatonin’s Impact on Antioxidative and Anti-Inflammatory Reprogramming in Homeostasis and Disease. Biomolecules. 2020 Aug 20;10(9):1211. doi: 10.3390/biom10091211. PMID: 32825327; PMCID: PMC7563541; regarding covid see also Tan DX, Reiter RJ. Mechanisms and clinical evidence to support melatonin’s use in severe COVID-19 patients to lower mortality. Life Sci. 2022 Apr 1;294:120368. doi: 10.1016/j.lfs.2022.120368. Epub 2022 Jan 30. PMID: 35108568; PMCID: PMC8800937.; see also Begum R, Mamun-Or-Rashid ANM, Lucy TT, Pramanik MK, Sil BK, Mukerjee N, Tagde P, Yagi M, Yonei Y. Potential Therapeutic Approach of Melatonin against Omicron and Some Other Variants of SARS-CoV-2. Molecules. 2022 Oct 16;27(20):6934. doi: 10.3390/molecules27206934. PMID: 36296527; PMCID: PMC9609612.; regarding cancer see Reiter RJ, Rosales-Corral SA, Tan DX, Acuna-Castroviejo D, Qin L, Yang SF, Xu K. Melatonin, a Full Service Anti-Cancer Agent: Inhibition of Initiation, Progression and Metastasis. Int J Mol Sci. 2017 Apr 17;18(4):843. doi: 10.3390/ijms18040843. PMID: 28420185; PMCID: PMC5412427.

10 Franks KH, Bransby L, Saling MM, Pase MP. Association of Stress with Risk of Dementia and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis. J Alzheimers Dis. 2021;82(4):1573-1590. doi: 10.3233/JAD-210094. PMID: 34366334.

11 Wang HX, Wahlberg M, Karp A, Winblad B, Fratiglioni L. Psychosocial stress at work is associated with increased dementia risk in late life. Alzheimers Dement. 2012;8(2):114-20. doi: 10.1016/j.jalz.2011.03.001. PMID: 22404853; see also Gonzalez-Mulé, E., & Cockburn, B. S. (2021). This job is (literally) killing me: A moderated-mediated model linking work characteristics to mortality. Journal of Applied Psychology, 106(1), 140–151. https://doi.org/10.1037/apl0000501; see also Gonzalez-Mulé E, Kim MM, Ryu JW. A meta-analytic test of multiplicative and additive models of job demands, resources, and stress. J Appl Psychol. 2021 Sep;106(9):1391-1411. doi: 10.1037/apl0000840. Epub 2020 Sep 21. PMID: 32955269.

12 Ouanes S, Popp J. High Cortisol and the Risk of Dementia and Alzheimer’s Disease: A Review of the Literature. Front Aging Neurosci. 2019 Mar 1;11:43. doi: 10.3389/fnagi.2019.00043. PMID: 30881301; PMCID: PMC6405479.13 Gonzalez-Bono E, Rohleder N, Hellhammer DH, Salvador A, Kirschbaum C. Glucose but not protein or fat load amplifies the cortisol response to psychosocial stress. Horm Behav. 2002 May;41(3):328-33. doi: 10.1006/hbeh.2002.1766. PMID: 11971667.

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Warning: Your Brain Is Being Hijacked… by Junk Food, Tech & Stimulants

We now know that today’s diet, lacking in brain-friendly fats and other nutrients, yet high in sugar and ultra-processed food, is likely to be shrinking our brains, dumbing us down and triggering a big increase in mental health problems. But it isn’t just nutrition that is creating the perfect storm for our mental demise.

The digital culture we exist in is pushing us towards a whole new paradigm of background stress. This is partly because the marketeers have learnt how to get us addicted to their products – applying a level of stress and variable reward to trick the brain’s reward system – leaving you with a ‘gotta have it’ feeling.

This mechanism of ‘variable reward’

This was first discovered in the 1930’s by the psychologist B.F. Skinner. He found that mice responded most frequently to reward-associated stimuli when the reward was given after a varying number of responses – so the animal didn’t know when it would get the prize. It seems we are no different; if we perceive a reward to be delivered at random, and if checking for that reward comes at little or no cost, we end up checking habitually.

So is this where smartphone addiction comes from?

This manipulation of the stress/reward response is one of the oldest mechanisms of the brain. It is both core for our survival, but also makes us more impulsive, manipulatable and, effectively, stupid.

Most of all, it makes us good consumers. Reward, based on dopamine, equals pleasure. We are living in space-age times with stone age minds and multinational companies have learnt how to get us hooked – literally neurochemically addicted to consuming their products.

We are being sold pleasure in the guise of happiness: the happy hour, the happy meal, happiness in a can. But joy and happiness are regulated by the neurotransmitter serotonin, not the latest special offer. And in fact, this pleasure-seeking may be counterproductive.

“The more pleasure you seek, the more unhappy you get” says Professor Robert Lustig, author of ‘Hacking the American Mind’. This is because too much dopamine (the ‘reward’ neurotransmitter) suppresses serotonin (the ‘happy’ neurotransmitter) and we end up feeling unhappy and depressed. This brain hijack may be why depression, suicide and psychiatric drug prescriptions have rocketed to the point where, in the UK and US (and probably elsewhere), there are almost twice as many prescriptions for psychiatric drugs per year than there are people.  

“We are the most in debt, the most obese, the most medicated and the most drugged up adult population in human history” says Lustig. We have literally learnt how to fool our brains and in doing so have fooled ourselves, by creating addictive behaviours and addictive foods. 

An example of this is what happens in your brain if you eat sugar and/or fat. 

Sugar…just like cocaine and heroin?

Sugar, just like cocaine and heroin, stimulates dopamine and endorphins. It triggers the reward system but with overuse, leads to reward deficiency (1). Dr Candace Pert, Research Professor in the Department of Physiology and Biophysics at Georgetown University Medical Center in Washington DC, and author of the seminal book ‘The Molecules of Emotion’, was the first to point this out in no uncertain terms: “I consider sugar to be a drug, a highly purified plant product that can become addictive. Relying on an artificial form of glucose – sugar – to give us a quick pick-me-up is analogous to, if not as dangerous as, shooting heroin. (2)” At the time, this was heresy but, today, most people are well aware of this. But it’s not just sugar that’s feeding our addiction.

Neuropharmacologist Professor Paul Kenny, a Dubliner now working in his Manhattan lab at Mount Sinai Hospital, discovered this when he started feeding rats different diets. When he fed one group of rats either lots of sugary foods and another group lots of fatty foods, neither group would gain much weight. They’d control their intake and it would take over a month to see a small weight gain. 

However, when he fed them a combination of 50% sugar and 50% fat, such as in a cheesecake, he noted the mice would “dive head first into a slice and gorge so vigorously that it covered its fur in blobs. It’s not pleasant.” After a binge on cheesecake they continued to graze, constantly eating food, he says, as if the off-switch telling them they were full had malfunctioned. “It completely changed them.” They stopped exercising and gained significant weight after only seven days. They also became addicted (3). When he took away the junk food and replaced it with healthy food they went on a hunger strike, refusing to eat it. 

He even tried to stop them by giving them an electric shock to their feet. “We then warned the rats as they were eating—by flashing a light—that they would receive a nasty foot shock. Rats eating the bland chow would quickly stop and scramble away, but time and again the obese rats continued to devour the rich food, ignoring the warning they had been trained to fear. Their hedonic desire overruled their basic sense of self-preservation.” 

Overeating, he found, juices up the reward systems in the brain — so much so, that in some people, it can overpower the brain’s ability to tell them to stop eating when they have had enough. As with alcoholics and drug addicts, the more they have, the more they want, creating a vicious cycle of dopamine resistance, eventually leading to the brain’s receptors for dopamine to shut down. 

It seems dopamine, the brain’s main neurotransmitter of reward and desire, is the key. 

Obese people and drug addicts have been shown to have less dopamine D2 receptors (D2R)s (4). People who are born with reduced levels of D2R are therefore at greater genetic risk of developing obesity and drug addiction – so you can be genetically predisposed to addiction. Researchers at Brookhaven National Laboratory and the Oregon Research Institute have shown that the reward system in obese people responds weakly to food, even to junk food(5). How does an individual overcome this absence of pleasure? By eating more pleasure foods to gain a temporary boost, thereby perpetuating the cycle. The researchers found that obese people may overeat just to experience the same degree of pleasure that lean individuals enjoy from less food.

Nicole Avena of the University of Florida, and others, have found that particular fats or sugars, sugars together with fats, and possibly salt, are the most addictive (6). A study by Professor David Ludwig of Boston Children’s Hospital suggests that highly processed, quickly digested fast carbs could trigger cravings (7). But research overall indicates that no one ingredient stokes food addiction better than the combo of fats and sugars, high in calories. Nature just doesn’t make these kinds of foods. Only the food industry does.

Similarly, cola drinks combine the stimulant caffeine, with sugar and salt, to make you drink more. And we crave sugary food and drink even more when fructose is used instead of glucose. Why? Because our cells run on glucose and quickly feedback when we’ve had enough. Fructose (or high fructose corn syrup, derived from corn) takes longer to send us that signal, leading us to consume more. No wonder then that glucose has been replaced by fructose and is a key ingredient in today’s ultra-processed foods.

Are you addicted to your smartphone?

Of all the changes that have taken place in the 21st century, the ‘digital revolution’ has changed our world beyond recognition, seemingly speeding up time. Yes, our diet and environment have changed a lot, but what’s really changed, especially in cities that now house half of humanity and an estimated two-thirds of the world’s population by 2035, is the pace of life. People all over the world are sleeping less, having less downtime, feeling more anxious and stressed and burning out at a far higher rate. This is reflected in the increasing rate of work absenteeism, depression and suicide, especially in cities.

The speeding up of communication – emails, smartphones and digital media – means that we are supposed to react to demands, and are bombarded with them, at an ever-increasing speed. 

We have literally become addicted to our phones(8). The average person picks up their phone 352 times a day – more than every three minutes, and swipes it thousands of times a day. A UK survey reports 62% cannot make it through dinner without checking their phone. Almost half of us report anxiety if we don’t have our phone, or a signal, suffering ‘nomophobia’. We are going to sleep with our phones and checking them first thing on waking up. One survey found that one in ten university students in the US admitted to having checked their smartphones during sex! 

Why? Basically, to sell stuff. “I feel tremendous guilt,” admitted Chamath Palihapitiya, former Vice President of User Growth at Facebook, to an audience of Stanford students. “The short-term, dopamine-driven feedback loops that we have created are destroying how society works.” Whether it’s Facebook, Instagram, Twitter, Snapchat, LinkedIn or any other platform, the core design is to get your attention, then show you ads tailored to your attributes and behaviours which the technology learns about you. Facebook, for example, has learnt how to do this with prompts, swipe downs, red icons that you press and don’t know what you receive. Is it a ‘like’? Do I have more ‘friends’? Or has another person ‘linked’ to me on LinkedIn etc. 

Facebook even knows when you’re feeling ‘insecure’, ‘worthless’ and ‘need a confidence boost’ or are ‘bored’, and can make sure you receive a notification of a ‘like’ at just the right time to keep you hooked. If you find yourself checking your phone at the slightest feeling of boredom, purely out of habit, know that programmers work very hard behind the screens to keep you doing exactly that. A study of 143 undergraduates at the University of Pennsylvania, limiting use to 30 minutes a day versus a control group found significant reductions in loneliness and depression (9). The researchers concluded, “Our findings strongly suggest that limiting social media use to approximately 30 minutes per day may lead to significant improvement in well-being.”

Whether it’s a text, a notification or a ‘like’, just like sugar, this digital consumption triggers a reward signal in our brains. The marketing algorithms schedule the precise times to deliver our digital diet and serve up the extra addictive quality of a variable reward.

Your brain’s reward system

It’s to do with a tiny organ in the central hippocampal area of the brain called the nucleus accumbens. This is the headquarters of our dopamine-based ‘reward’ system.

The more dopamine you release the more receptors shut down, so you seek more pleasurable behaviours and foods. Insidiously and unknowingly your brain has been hijacked and the symptoms you feel are the direct consequences of an intended addiction. Gambling, gaming, overeating, sex, drugs, food, social media and other digital addictions are all part of it. We end up needing this constant stimulation and, to fuel that, need instant energy foods and drinks – sugar and coffee. 

Alcohol – the opiate of the masses

Whether you’ve become addicted to sugar, food, caffeinated drinks, social media, gambling, gaming or non-stop stimulation, or simply get caught in the stress trap, perhaps due to work and life demands and debts, this often results in an inability to switch off with a background feeling on anxiety and stress without alcohol, and difficulty sleeping. 

You may find, in time, that your need for alcohol increases – from a glass a night to two, three, half a bottle or even more. Alcohol, a well-established neurotoxin (10), surely is the opiate of the masses. Consumption keeps going up. It’s the currency of a good time, normalised as a response to stress, glorified in movies and at the core of our modern culture, with a 1.5 trillion dollar industry, expected to rise to 2 trillion by 2027 (11), promoting its use. While smoking has become frowned upon, anything other than heavy drinking is considered socially acceptable. Yet according to WHO alcohol is in the top five causes of death and disability, and has become the most common cause of death in men under 50 (and soon will be for women), accounting for one-fifth of all deaths under 50 and almost 30,000 deaths a year overall, roughly a third that of smoking and ten times more than opioids (inc heroin) and is ranked more harmful than any other drug, including opioids (12). This addictive drug is so socially acceptable that governments avoid attempts to curtail its use for fear of voter reprisals.

A commonly unknown fact is that death or disability from alcohol doesn’t only occur in heavy drinkers. The risk goes up exponentially with the quantity you drink. The good news is that small reductions have big positive effects on your health. To make this real, a 12.5% vol. bottle of wine contains 75g alcohol: drinkers who have 2/3rds of a bottle of wine (two large glasses) or the equivalent 50g of alcohol, have a lifetime risk of death of 16%. But one medium glass (175ml) of wine (17.5g of alcohol) brings that risk below 1%. In terms of mitigating serious health risks, including death, the advice of the UK government’s former advisor, Professor David Nutt, is for women to consume no more than 15g of alcohol per day  and for men no more than 20g alcohol per day, and to have at least two alcohol-free days per week. Sadly, Professor Nutt was sacked for saying that alcohol was a ‘time bomb’ and more dangerous than Ecstasy, but the statistics point to this being true.

The trouble is, when you get stuck in the cycle of seeking rewards, needing stimulants and relaxants, you become more tired, more anxious and may even have started to feel more depressed. 

When things get bad and you visit your doctor they may prescribe antidepressants, tranquillisers (short-term use only) or sleeping pills. Others learn to use illicit uppers and downers.

Are you addicted to stimulants?

The other major acceptable and glorified drug is caffeine, mainly in the form of coffee, although many people don’t realise that strong tea has as much caffeine as a regular cup of coffee. Like sugar, alcohol and our digital diet, it stimulates dopamine release and the feeling of pleasure or reward. Imagine a day with no coffee, tea, sugar, chocolate or that well-earned glass of something! If you shout, ‘No way!’ there is a very real possibility that you have some level of addiction to these stimulants. This can range from a mild addiction that you can live with quite happily to a major problem that is controlling your life. 

However, whatever the level of addiction, the net consequence is always less energy, not more. One of my clients, Bobbie, serves as a case in point. She was already eating a healthy diet and took a sensible daily programme of vitamin and mineral supplements. She had only two problems: a lack of energy in the morning and occasional headaches. She also had one vice: three cups of coffee a day. After some persuasion, she agreed to stop the coffee for a month. To her surprise, her energy levels rose and the headaches stopped. 

Like Bobbie, it’s useful to audit your stimulant consumption from time to time. Using a Stimulant Inventory below can be helpful, but in making an accurate assessment of your current relationship to stimulants, you need to be honest with yourself about how you use them. There’s a space for alcohol which, while not a stimulant, still triggers those dopamine receptors.

It’s useful to write down the time of day you consume the above and to spend time thinking about what your relationship to these substances is. 

  • Do you, for example, ever buy sweets and hide the wrappers so other people don’t know you’ve eaten them? 
  • Do you swoon at the dessert menu in restaurants? 
  • How much do you think about and look forward to that morning cup of coffee or a mid-morning second cup? 
  • How important is that drink after work?
  • Does everyone really know how much you smoke? 
  • Have you cranked up your caffeine intake to ‘double espresso’ equivalent drinks using more coffee at home than you used to? 
  • Do you need more to get a ‘kick’ if you even get one, or does coffee now just relieve the fuzzy tiredness you feel without it?

This kind of relationship to stimulants, often cloaked in an attitude that they are just some of the innocent pleasures of life, is indicative of an underlying chemical imbalance that depletes your energy and peace of mind and, at its worst, feeds into mental health issues.

Coffee and Caffeine Withdrawal and Sleep

If you wake up feeling good and can function without a coffee, and have no major mental health issues, sleeping well for example, but enjoy one coffee a day which will give you a dopamine kick, that’s not a problem. The best measure of your relationship with coffee or caffeine, and whether your brain has ‘downregulated’ dopamine and adrenaline receptors is what happens when you quit. If the answer is nothing then there’s no issue. If, on the other hand, you get a variety of withdrawal symptoms (13), including headaches, tiredness and irritability that means your neurotransmitter receptors have downregulated and it will take a few days for them to upregulate and bring you back to normal. For many just one cup of coffee a day can result in withdrawal effects if stopped (14). It’s also worth knowing that coffee, or caffeine, consumed 6 hours before sleep, which is about as long as caffeine stays in the system, is associated with disturbed sleep (15) – either difficulty falling asleep or waking in the night so, at least, it is wise to consume no caffeine after noon, especially if you have issues with sleeping.

Tea or coffee?

The caffeine in both coffee and tea increases the release of adrenalin, cortisol and dopamine in your body and brain, while inhibiting the absorption of adenosine, a brain-calming chemical. The release of adrenaline into your system gives you a temporary boost, but frequently makes you fatigued and depressed later. If you take more caffeine to counteract these effects, you end up spending the day in an agitated state, and might find yourself jumpy and edgy by night.

Tea contains caffeine, but also theanine, which has a more calming amino acid shown to enhance cognitive abilities (16). It also protects GABA receptors, which is the brain’s adrenalin off switch. Overall then, tea is better for you. Green tea may also have some benefits over black tea (the same plant, but processed differently such that green tea contains more antioxidants and polyphenols, which are good guys as far as our bodies are concerned).

Benefits or excuses?

Many things could be written on the apparent benefits of tea, coffee, even some forms of alcohol. We read about the beneficial effects of resveratrol in red wine, polyphenols in coffee and cacao and other antioxidants in tea. However, the nature of ANY dependence creates a psychological set of ‘excuses’ that we use to justify our addictive behaviour. 

This could be anything from ‘that’s a lovely sauce’ (sugar), ‘a little bit of what you fancy won’t harm you’ ‘I’m so stressed I have to have a drink’, ‘I’ve got to focus so I need a coffee’ and so on. Of course, all these substances work, otherwise we wouldn’t be attracted to them and, in that sense, mindful consumption in certain circumstances makes sense. For example, if someone experiences a shock, a sugary drink can help. And when a deadline looms and you need to burn the candle at both ends, caffeine can certainly help.

The issue here is to understand how the combination of sugar, caffeinated stimulants, alcohol, tech and social media addiction, shopping, gambling, gaming and so on can hijack your brain’s natural reward system and result in the opposite – you feeling more tired, anxious, unfulfilled and depressed. If that’s happened to you, rest assured there are some simple suggestions that will help you reclaim your brain’s full potential for feeling good, energised, clear, focussed and purposeful.

Simple ways to win back your brain
  • Limit your time spent on social media – 30 minutes a day max is a good target but you may need to build down to this. Turn your phone off (or to ‘airplane’ mode) at least an hour before bed and keep it that way for at least an hour in the morning. If you have to have it on, don’t check social media for a couple of hours. 
  • Limit your intake of caffeine to under 100 grams a day – that’s one strong cup of coffee or two weaker cups of tea. If you have a second cup, use the same tea bag, or have a filter coffee ‘run through’. Avoid all caffeine after noon.
  • Avoid buying food that contains added sugar, dates or raisins – if in doubt, read the label and remember sugar is often disguised as high fructose corn syrup. When looking at food labels remember 5g is a teaspoon of sugar and foods with more than 22.5g per 100g of sugar are considered high sugar and those with 5g or less per 100g are considered low sugar. Ideally, only have sugar in whole fresh fruits. Fruit juice is also high in sugar so best avoided or limited. 
  • Limit your daily intake of alcohol to 20 grams, or a maximum of two small glasses (125ml is one small glass) of wine. Have at least two days a week alcohol-free.

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References

1 P. Holford, How to Quit Without Feeling S**t, Piatkus, 2008.

2 P. Holford, How to Quit Without Feeling S**t, Piatkus, 2008.

3 P.M. Johnson and P.J. Kenny ‘Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats’, Nature Neuroscience (2010), vol. 13(5), pp. 635-641. 

4 .P. Kenny ‘Reward Mechanisms in Obesity: New Insights and Future Directions’ Neuron. 2011 Feb 24; vol 69(4): pp.664–679. 

 5  See ref 4 above

6 N.M. Avena and M.S. Gold, ‘Food Addiction – Sugars, Fats and Hedonic Eating’, Addiction (2011), vol. 106(7), pp. 1214-1215.

7 B. Lennerz et al., ‘Effects of dietary glycemic index on brain regions related to reward and craving in men’ The American Journal of Clinical Nutrition, Volume 98, Issue 3, 1 September 2013, Pages 641–647

9 https://guilfordjournals.com/doi/10.1521/jscp.2018.37.10.751

10 Nutt, D.;Hayes,A.; Fonville, L.; Zafar, R.; Palmer, E.O.; Paterson, L.; Lingford-Hughes, A. Alcohol and the Brain. Nutrients 2021, 13,3938. https://doi.org/10.3390/ nu13113938

11 https://www.statista.com/forecasts/696641/market-value-alcoholic-beverages-worldwide

12  David J Nutt and Jürgen Rehm J Psychopharmacol 2014 28: 3 DOI: 10.1177/0269881113512038 

The online version of this article can be found at: http://jop.sagepub.com/content/28/1/3

13 https://www.ncbi.nlm.nih.gov/books/NBK430790/

14 Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl). 2004 Oct;176(1):1-29. doi: 10.1007/s00213-004-2000-x. Epub 2004 Sep 21. PMID: 15448977.

15 Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013 Nov 15;9(11):1195-200. doi: 10.5664/jcsm.3170. PMID: 24235903; PMCID: PMC3805807.

16 Anas Sohail A, Ortiz F, Varghese T, Fabara SP, Batth AS, Sandesara DP, Sabir A, Khurana M, Datta S, Patel UK. The Cognitive-Enhancing Outcomes of Caffeine and L-theanine: A Systematic Review. Cureus. 2021 Dec 30;13(12):e20828. doi: 10.7759/cureus.20828. PMID: 35111479; PMCID: PMC8794723.

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