Our Children No Longer Need to Worry About Our Cognitive Decline

What one family learned from living through dementia and why they decided to take action.

When dementia affects a family, the impact often extends far beyond the person who receives the diagnosis. Many people begin to worry about cognitive decline, wondering whether it is an inevitable part of ageing or whether there is anything they can do to reduce their risk.In this story, Peter shares how watching his mother develop dementia changed the way he and his wife thought about ageing, why they decided to take a more proactive approach to their brain health, and how that decision ultimately gave their children something they hadn’t expected: peace of mind.

Most people do not start thinking seriously about dementia until it touches someone they love. Yet every day in the UK, around 790 people receive a dementia diagnosis, the equivalent of seven double-decker buses full of families beginning a journey they never expected to take.

Why One Family Decided Not to Worry About Cognitive Decline

For Peter and his family, dementia was not something they read about in the news or encountered through awareness campaigns. It arrived at their front door.

As his mother’s dementia progressed, the family witnessed first-hand how profoundly the condition could affect daily life. For a period, she lived with Peter and his wife, giving them a close-up view of the challenges, heartbreak, and uncertainty that often accompany cognitive decline.

Their children were young when their grandmother first became unwell and were old enough to witness much of what followed. They saw the gradual changes in her memory, independence, and ability to live the life she had once enjoyed. Like many families affected by dementia, they adapted as best they could, but experiences like these leave their mark.

Should You Worry About Cognitive Decline if Dementia Runs in Your Family?

At first, the family’s focus was entirely on supporting a much-loved mother and grandmother. Then, as they watched dementia unfold over many years, the children naturally started asking questions about the future. What would happen to their parents? Was this simply what ageing looked like? Could anything be done to reduce the risk of dementia?

For Peter, this became one of the most difficult parts of the journey.

When his mother died in 2016, he and his wife found themselves reflecting on everything the family had been through. They knew there were no guarantees when it came to health and ageing, but they also felt increasingly uncomfortable with the idea of simply hoping for the best.

Instead, they made a decision. Rather than focusing on what they could not control, they would focus on what they could.

That decision marked the beginning of a journey that continues today.

What to Do Instead of Worrying About Cognitive Decline

Peter’s interest in health had not appeared overnight.

Years earlier, they had discovered Patrick Holford’s work and become increasingly interested in nutrition and healthy ageing. Like many people, they had spent years trying to understand how food, lifestyle, and everyday habits influence long-term wellbeing.

Dementia, however, gave that interest a new urgency, as brain health was no longer an abstract topic. It had become deeply personal.

Instead of feeling powerless, they wanted to understand more about the factors associated with cognitive decline and, more importantly, what practical steps they could take to support healthy brain ageing. This led them to Food for the Brain’s educational resources, the Cognitive Function Test, and DRIfT biomarker testing.

They were not looking for guarantees or predictions about the future. They wanted a clearer understanding of where they stood and, perhaps more importantly, what they could actually do about it.

Measuring What Matters

The first steps? Understanding where they actually stood.

After years of watching dementia affect someone they loved, they wanted more than good intentions. They wanted a clearer picture of their current health and a better understanding of where they should focus their efforts.

The Cognitive Function Test provided one piece of that picture. Having first completed the assessment around 2012, Peter returned to it years later with a renewed interest in dementia prevention and healthy ageing. His score improved from 51 to 73.

The score itself was only part of the story. What mattered more was having a way to check in on how things were going. After everything the family had been through, it felt reassuring to have something tangible to measure rather than simply wondering whether their efforts were making a difference.

Alongside cognitive testing, they also began monitoring several biomarkers associated with brain health through DRIfT testing and implementing the guidance they were given along the way. The results showed encouraging changes across a number of areas:

Key Changes Over Time

His homocysteine level proved particularly useful information. Although he had already made a number of dietary and lifestyle changes, his levels remained higher than he would have liked, hovering at around 12 µmol/L across several tests. Regular testing allowed him to identify the issue, make further adjustments, and see how his body responded over time. After introducing vitamin B12, his homocysteine eventually reduced from 11.9 µmol/L to 7.16 µmol/L.

Without testing, he would never have known that this important marker remained elevated, as it is not something you can feel. Equally, without repeating the test, he would never have known whether the changes he made were having the desired effect. never have known whether the changes he made were having the desired effect.

Lifestyle Changes That Reduced Their Worry About Cognitive Decline

There was no single intervention that transformed their health overnight. Instead, they gradually reshaped the way they lived. Ultra-processed foods disappeared from the shopping trolley, wheat was removed from the diet, fermented foods became a regular feature at mealtimes, and targeted supplements were added where testing suggested they might be beneficial. Alongside this, they stayed physically active, walked regularly, and continued to challenge themselves mentally through activities such as completing The Times crossword.

Like many people who successfully improve their health over the long term, they did not follow a perfect plan or look for a magic solution. They focused on making changes they could sustain and enjoy, building habits that fitted naturally into the life they wanted to lead in retirement.

In many ways, their experience reflects what the research increasingly tells us about brain health: it is rarely one single intervention that matters most, but the cumulative effect of multiple factors working together over time, from nutrition and exercise to sleep, metabolic health, social connection, and lifelong learning.

The Difference It Made

Over time, they began to notice subtle shifts. Their thinking felt clearer, they felt more optimistic about ageing, and they gained confidence from seeing improvements in some of the markers they were tracking. Yet perhaps the biggest change was not physical at all. For years, dementia had been something that happened to their family. Now, instead of feeling defined by that experience, they felt they were actively shaping what came next.

The conversations within the family began to change, too. Their children and their children’s partners became more interested in brain health, nutrition, and prevention, turning what began as one family’s experience of dementia into a wider conversation about healthy ageing. Rather than seeing cognitive decline as an inevitable part of getting older, the family started to see it through a different lens, one that recognised the role informed choices can play in supporting long-term brain health.

When asked what has mattered most, Peter does not talk about biomarkers, supplements, or cognitive test scores. He returns instead to the concern that first motivated him and his wife to take action. Watching their grandmother’s decline had left a deep impression on the children, who naturally worried about what the future might hold for their parents. Those concerns did not disappear overnight, but they gradually eased as they saw their parents taking positive action, learning more about brain health, and making it a priority.

Reflecting on everything that had changed, one thought stood above all the others:

For Peter, that is the result that matters most.

Want to understand your own brain health?

Peter’s experience is not really about a test score, a supplement, or a blood result. Those were simply tools that helped him and his wife better understand their health, make informed decisions, and feel more confident that they were moving in the right direction.

At its heart, this is a story about a family who experienced dementia first-hand and decided not to leave the future entirely to chance. It is about protecting independence, preserving memories, staying connected to the people we love, and approaching later life with greater confidence and optimism.

At Food for the Brain, we believe more people deserve the opportunity to do the same. As a research and education charity, our mission is to make dementia prevention and optimal brain health possible by translating the latest science into practical, accessible actions that people can take today. Through research, education, testing, and behaviour-change programmes, we help people understand their brain health and take positive action while there is still time.

Related reading:

25 Daily Habits To Reduce Dementia Risk
Four Quick Wins to Reduce Your Risk of Alzheimer’s
Preventing Alzheimer’s Disease

Algae Oil vs Fish Oil for Brain Health: What’s the Difference?

If you’ve spent any time reading about brain health, you’ve probably come across omega-3s. When it comes to choosing a source of these essential nutrients, many people weigh up Algae Oil vs Fish Oil. They are one of the most researched nutrients in dementia prevention, cognitive function and healthy ageing, yet one surprisingly common question remains:

Does it matter where your omega-3s come from?

For years, fish oil was considered the gold standard. More recently, algae oil has emerged as an alternative that is popular with vegetarians, vegans and those who simply prefer a tasteless supplement. But does algae oil offer the same brain health benefits as fish oil, or is one genuinely better than the other?

The answer is more interesting than you might think.

Why Omega-3s Matter for Brain Function and Healthy Ageing

When we talk about omega-3s and brain health, we are mainly referring to two fatty acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

DHA is particularly important because it forms part of the structure of brain cells themselves. In fact, DHA is one of the most abundant fats found within the brain, helping maintain healthy cell membranes and supporting communication between neurons.

EPA appears to play a slightly different role. It is involved in regulating inflammation, blood flow and a number of processes linked to mood and cognitive function.

Research has consistently linked higher omega-3 status with better cognitive performance, healthier brain ageing and a lower risk of cognitive decline. Some of the most fascinating findings come from the Oxford VITACOG studies, which examined the relationship between omega-3s, B vitamins and brain ageing.

Researchers found that participants with higher blood levels of omega-3s gained significantly greater benefits from homocysteine-lowering B vitamins than those with lower omega-3 levels. Those with both adequate omega-3 status and B vitamin support experienced slower rates of brain atrophy and reduced cognitive decline compared with those who had lower omega-3 levels [3,4].

Interestingly, emerging research suggests that maintaining adequate omega-3 levels may be particularly important for women. Hormonal changes associated with ageing can influence brain health, inflammation and cognitive resilience, making omega-3 status an important consideration throughout later life. You can learn more in our article on why women’s brains need omega-3 now.

The simple takeaway is that omega-3s appear to be an important part of protecting the brain as we age. They also do not work in isolation. Like most nutrients, they seem to be most effective when part of a wider network of nutrients and healthy lifestyle factors.

Want a quick overview before we compare algae oil and fish oil? This short video explains why omega-3s are so important for brain health and healthy ageing.

Algae Oil vs Fish Oil: What’s the Difference?

Fish oil is extracted from oily fish such as sardines, anchovies and mackerel and has been the most widely used source of EPA and DHA for decades.

Algae oil, on the other hand, is derived directly from marine microalgae.

This distinction is important because fish do not actually produce omega-3 fats themselves. Instead, they accumulate EPA and DHA by consuming algae and other organisms within the marine food chain [5].

In other words, algae are the original source of the omega-3 fats found in fish.

From a nutritional perspective, both fish oil and algae oil can provide the same biologically active forms of omega-3. The main differences relate to dietary preference, manufacturing methods and the specific balance of EPA and DHA provided by individual products.

If you’re considering an omega-3 supplement, it’s worth understanding the differences between EPA and DHA, how much you may need, and what to look for when choosing a quality product. Our comprehensive guide to omega-3 supplements covers the evidence, recommended intake levels and key considerations before you buy.

Algae Oil vs Fish Oil: Key Differences

Is Algae Oil as Effective as Fish Oil?

Fish oil still has one clear advantage: it has been studied for much longer.

As a result, there is currently a larger body of research investigating fish oil supplementation and health outcomes. That does not necessarily mean fish oil is superior, only that it has a longer research history.

More recently, scientists have started directly comparing fish oil and algae oil. A 2025 human trial found that algae-derived EPA and DHA were absorbed just as effectively as omega-3s from fish oil when equivalent doses were provided [6].

This is an important finding because it suggests the body is able to utilise EPA and DHA from algae in much the same way as EPA and DHA from fish oil. For people who do not eat fish, follow a plant-based diet or simply prefer a tasteless source of marine omega-3s, algae oil appears to be a credible alternative rather than a compromise.

Omega-3s, B Vitamins and Dementia Prevention

There are two topics we love talking about at Food for the Brain: omega-3s and homocysteine. While they might seem unrelated, some of the most exciting dementia prevention research suggests they may be more connected than we once thought.

One reason omega-3s have become such an important focus in dementia prevention research is their relationship with homocysteine. Homocysteine is a naturally occurring amino acid that, when elevated, is associated with a greater risk of cognitive decline and dementia. B vitamins, particularly folate, vitamin B12 and vitamin B6, help keep homocysteine levels under control.

In the landmark VITACOG trial, homocysteine-lowering B vitamins significantly slowed the rate of brain shrinkage in older adults with mild cognitive impairment [1]. Further analysis showed that these benefits were strongest among participants with higher omega-3 levels [3,4].

This helps explain why many practitioners now assess both homocysteine and omega-3 status when considering an individual’s long-term brain health. This highlights an important lesson in nutrition: it is rarely one nutrient acting alone. The greatest benefits usually come from the interaction between multiple nutrients and healthy lifestyle factors working together. (Which is why we have our 8 nutrition and lifestyle domains in the COGNITION online community and programme.)

Don’t Guess Your Omega-3 Status

One of the biggest misconceptions about omega-3 supplementation is that taking a supplement automatically means your levels are optimal.

In reality, omega-3 status varies considerably from person to person. Genetics, absorption, diet, dosage and supplement quality can all influence the amount that ultimately reaches your bloodstream. Two people taking the same supplement may achieve very different results.

That is why, at Food for the Brain, we believe testing is often more useful than guessing.

The DRIfT test measures several important biomarkers linked to brain health, including omega-3 status, homocysteine, vitamin D, HbA1c and glutathione. Rather than assuming your current diet or supplement routine is working, testing can help identify where support is needed and allow you to take a more personalised approach to protecting your brain health.

Algae Oil and Fish Oil: Key Takeaways for Cognitive Health

Both fish oil and algae oil provide the EPA and DHA associated with healthy brain ageing and cognitive function.

Fish oil remains the most extensively studied source and continues to have the largest body of evidence behind it. However, current research suggests that algae oil can raise blood levels of EPA and DHA just as effectively, making it a viable option for those who prefer not to use fish-derived products [6].

Perhaps the most important lesson from the research is that taking an omega-3 supplement is only part of the story. What ultimately matters is whether those omega-3s are reaching meaningful levels in your bloodstream and, ultimately, your brain.

The real question might not be whether your omega-3 comes from fish or algae.

The real question is whether your brain is getting enough.

Next Steps:

Food for the Brain is a not for profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index. This allows them 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.

Related reading:

Alzheimer’s: Why prevention is better than drugs – but less profitable
How to Keep Building Brain Cells at Any Age

Chromium, Blood Sugar and Brain Health: The Overlooked Connection

How Blood Sugar Regulation Affects Brain Function?

When people think about protecting their brain, they often focus on keeping mentally active, reducing alcohol, or hoping they avoid dementia as they get older, somehow? But nutrients and minerals like chromium may also play a role in brain health.

Few think about blood sugar.

Yet every thought, memory, conversation, and decision relies on a constant supply of energy. Increasingly, researchers are discovering that how effectively we regulate blood sugar and respond to insulin may play an important role in how our brains function and age. (1)

This is where chromium enters the story.

Although only required in tiny amounts, chromium plays an important role in normal carbohydrate, fat, and protein metabolism. Its best understood role is helping insulin do its job more effectively. Insulin is the hormone that helps move glucose from the bloodstream into cells, where it can be used for energy, and chromium appears to support this process. (2)

The Brain’s Energy Demand and Glucose Supply

The brain represents only around 2% of body weight, yet uses roughly 20% of the body’s energy. (3) To function properly, brain cells require a continuous supply of fuel. Most of the time, that fuel comes from glucose, although the brain can also use ketones under certain circumstances.

When insulin is working well, glucose can be transported efficiently to the cells that need it. When cells become less responsive to insulin, a state known as insulin resistance develops. Blood sugar levels may rise, inflammation can increase, and energy production becomes less efficient.

Importantly, insulin resistance does not just affect muscles, fat tissue, and the liver. It also affects the brain.

Researchers have linked impaired insulin signalling with changes in brain structure and function, while people with type 2 diabetes consistently show a higher risk of cognitive decline and dementia than those with healthy glucose regulation. (4)

This growing body of evidence is changing how scientists think about brain health. Protecting the brain is not only about keeping it stimulated and active. It also depends on how effectively the body produces, regulates, and delivers energy to brain cells throughout life.

Chromium and Blood Sugar Regulation

Chromium is found naturally in foods including shellfish, meat, eggs, broccoli, and whole grains.

In terms of how it works, you can think of insulin as a key trying to unlock the door to a cell, and chromium appears to help that key work more efficiently, allowing glucose to move where it is needed and be used for energy. (2)

This has led researchers to investigate whether chromium supplementation might support healthy blood sugar regulation. Results have been mixed, but overall, the evidence suggests chromium may help improve fasting glucose in some individuals, particularly those with impaired glucose control or type 2 diabetes. (5)

That does not make chromium a miracle nutrient, nor does it mean everyone should supplement with it. What it does suggest is that even relatively small nutrient deficiencies may influence how effectively the body’s blood sugar regulation systems operate.

Insulin Resistance, Dementia and Brain Health

Unlike omega-3 DHA and B vitamins, which work together to support the formation, maintenance, and communication of brain cells, chromium’s role appears to be less about building brain tissue directly and more about helping to regulate the energy supply those cells depend upon.

Its potential relevance lies in the fact that the brain is one of the most energy-demanding organs in the body. If insulin resistance increases the risk of cognitive decline, it is reasonable to ask whether nutrients involved in healthy insulin function might also matter for long-term brain health.

We do not yet have evidence that chromium supplementation directly reduces dementia risk. However, the connection between insulin resistance and brain health is now difficult to ignore, making nutrients that support healthy glucose regulation increasingly worthy of attention.

In other words, chromium is interesting not because it is a brain nutrient, but because it sits within a system that appears to be highly relevant to how the brain functions and ages.

Chromium, Mood and Sugar Cravings

Interestingly, chromium’s effects may extend beyond glucose regulation.

Several small studies have explored chromium supplementation in people with atypical depression, particularly where symptoms include fatigue, increased appetite and carbohydrate cravings. Some reported improvements in mood and reductions in cravings, while researchers have also proposed possible effects on neurotransmitter systems involved in mood regulation. (6)

These studies are small and far from definitive, but they point towards something that is becoming increasingly clear: metabolism and mental health may be far more connected than we once believed. So much so that entire fields such as metabolic psychiatry and nutritional psychiatry have emerged in recent years. Researchers including Christopher Palmer and Georgia Ede are helping to challenge the idea that mental health exists solely in the brain, highlighting the important role that blood sugar regulation, nutrient status, inflammation and cellular energy production may play in our mental health and resliency.

Why Metabolic Health and Chromium Matters for the Brain

The story of chromium is not really about chromium.

It is about systems.

For decades we have tended to separate brain health from metabolic health. We talk about memory, dementia and cognition on one side, and blood sugar, insulin and diabetes on the other.

Increasingly, the science suggests these systems are deeply interconnected.

Reducing excess sugar intake remains one of the most important things we can do for long-term health. But this also raises an interesting question. What if someone is already eating relatively well, yet their blood sugar regulation remains less than optimal? Could nutrient status be part of the picture?

Chromium is unlikely to be the missing piece for everyone. In fact, many multivitamins already contain small amounts. But it serves as a useful reminder that healthy insulin regulation depends on more than simply avoiding sugar. It relies on a network of nutrients, hormones and metabolic processes working together.

This is one reason we include HbA1c in the DRIfT blood test. HbA1c provides insight into how effectively blood sugar has been regulated over the previous two to three months and can help identify an often-overlooked aspect of brain health long before symptoms appear.

Next Steps:

Food for the Brain is a not for profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index. This allows them 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.

Related reading:

Depression
Make Eating Less Sugar Easier (& a FREE Recipe!)

Is China’s Alzheimer’s Nightmare Becoming Our Reality?

Patrick Holford examines how China is advancing Alzheimer’s prevention through nutrition, lifestyle and digital health initiatives, while questioning the pace of policy action in the UK.

The Race to Prevent Alzheimer’s in China

If there is one country that has to move fast to prevent Alzheimer’s, it is China. And it is.

With almost a quarter of its population over 60, some 320 million people, and an estimated 20 million expected to have Alzheimer’s by 2030, costing close to a trillion dollars a year, government health officials are taking prevention very seriously indeed.

Those over 60 are not called old, elderly, or senior, but “silver-haired“, a growing community that is at the heart of China’s health prevention strategies.

The doctor in charge of the Silver-Haired Healthy Lifestyle campaign is Dr Zhang Lei. He is a famous TV doctor and former surgeon.

I asked him if he believed there would ever be a cure for Alzheimer’s.

“Prevention is the cure,” he said. “And I want to make a special announcement. Next year, when your excellent book Alzheimer’s: Prevention is the Cure is published in Chinese, we will use this book as the cornerstone of our national prevention campaign. We already have direct access to 20 million people through our networks, but our ambition is to reach as many as 100 million. We will encourage everyone to take the online Cognitive Function Test from Food for the Brain. This book and this tool together will be our roadmap for a prevention revolution in China.”

Prevention-First Approach

I attended and spoke at the 2nd Silver-Haired Healthy Lifestyle Conference, where I met hundreds of silver-haired people like myself. The event was attended by 2,500 people and broadcast to 10 million people across twenty TV channels.

Other speakers included leading professors of public health, nutrition, gerontology and geriatrics, all delivering positive and progressive messages about prevention, including eating more seafood and vegetables, stopping smoking, cutting right back on sugar, sleeping better and taking 10,000 steps a day.

I spoke about the essential need for, and codependence of, omega-3, phospholipids and B vitamins. If omega-3 were the man and phospholipids, rich in eggs and seafood, were the woman, then B vitamins are the priest, I said. When they are married in your brain, magic happens. Together, they are the three building blocks of every brain cell.

You could have heard a pin drop. Everyone was listening and, in China, action is taken quickly.

The former Health Minister said that “diet, supplements and lifestyle” are the cornerstones of prevention. “We need education, not medication.“

No one was talking about anti-amyloid treatments.

Prevent Alzheimer’s at Scale

Next year, when the 3rd Healthy Lifestyle Conference coincides with the Chinese publication of my book Alzheimer’s: Prevention is the Cure, I have been invited to speak at universities and health departments across China.

Many silver-haired people in China do not have computers, but they all have smartphones. There are virtually no physical wallets. Communication and payment are conducted through the WeChat app.

The professors and public health officials were therefore very excited about our online digital test. They want to get everyone using Food for the Brain’s Cognitive Function Test. The COGNITION questionnaire then helps people understand which specific prevention steps are most relevant to them.

The experts, health authorities and policymakers understand that changing behaviour is the hardest part, and that this kind of personalised digital technology is key to motivating individuals and measuring change to find out what really works. It is big-data science helping to sharpen prevention strategies.

Why China Is Embracing Nutrition Over Medication for Brain Health

Traditionally, Chinese culture sees food as medicine, which may be one reason people are more open to optimum nutrition. There is also a long tradition of using natural compounds to support health, so supplements are a natural extension of this way of thinking.

Not one person repeated the old myth that “you can get all the nutrients you need from a well-balanced diet“.

The stark ignoring of established scientific facts about, for example, B vitamins and omega-3, which have outperformed anti-amyloid treatments, by our politicians and health ministers is verging on outrageous when the lives and brains of so many are at stake.

China’s High-Speed Lesson for Alzheimer’s Prevention

As I sat on a high-speed train travelling 1,200 kilometres from Shanghai to Beijing in just 3.5 hours, faster than taking a plane, and capable of speeds of 650 kilometres an hour, I found myself contemplating how the UK has yet to deliver the promised high-speed rail line from London to Birmingham, a little over 100 miles, despite more than a decade of work, a projected cost of over £100 billion, and a journey time saving of less than half an hour.

If this same failure to translate prevention science into policy continues, as it has over the past two decades, offering platitudes about the importance of prevention but little action, while continuing to avoid the scientific evidence of what actually works, then China’s nightmare of a large proportion of its silver-haired population slipping into dementia will become our reality.

Alzheimer’s is preventable. That is a fact, not a belief.

Those who say it cannot be done should not stand in the way of those who are doing it.

Food for the Brain is a not for profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index. This allows them 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.

Related reading:

Dementia Prevention Goes Global
China Is Taking Prevention Seriously In The ‘silver-haired’ Economy
Alzheimer’s: Why Prevention is Better than Cure

Amyloid isn’t Alzheimer’s – How NOT to Study a Disease

by Patrick Holford

Alzheimer’s disease has, for decades, been framed primarily as a problem of amyloid plaques building up in the brain.

It is a compelling idea. It is measurable, visible on brain scans, and has shaped billions in research funding and drug development. There’s just one problem.

It doesn’t adequately explain what we see in people.

Many individuals with significant amyloid in their brains remain cognitively normal. Others develop clear dementia with little or no amyloid present (1). Treatments that successfully reduce amyloid have, at best, produced only modest effects on slowing decline, with no meaningful reversal of symptoms (2).

Amyloid is associated with Alzheimer’s disease, but association is not the same as causation.

And that distinction changes everything.

This growing tension between theory and evidence is explored in depth by neurobiologist Karl Herrup in How Not to Study a Disease, where he challenges how the field has come to define and pursue Alzheimer’s.

Some people develop increasingly severe cognitive decline as they age. This affects roughly one in ten older adults. We call this dementia. In some cases, brain scans show clear shrinkage in key regions, particularly the medial temporal lobe, which is then used to diagnose Alzheimer’s disease. So we have two observable features: a decline in cognitive function and measurable loss of brain tissue.

The question that follows is simple, but critical.

What is actually causing this process?

What causes Alzheimer’s?

Amyloid has long been positioned as the answer. Yet the evidence tells a more complicated story.

A significant proportion of older adults have amyloid plaques in their brains and remain cognitively normal. At the same time, some individuals with clear dementia show little or no amyloid pathology. Amyloid is associated with Alzheimer’s, but that is not the same as being the cause.

If amyloid were the primary driver, then reducing it should meaningfully change the course of the disease. However, interventions designed to reduce amyloid have consistently lowered amyloid burden in the brain, yet produced, at best, modest effects on slowing decline, often measured as very small changes on cognitive scales. There has been no meaningful reversal of symptoms. In some cases, safety concerns have emerged, including brain bleeding and swelling.

Recent large-scale evidence (6) now reinforces this point. A 2026 Cochrane review concluded that although anti-amyloid monoclonal antibodies can remove amyloid from the brain, this does not appear to translate into clinically meaningful effects for people with mild cognitive impairment or mild dementia due to Alzheimer’s disease, while increasing the risk of amyloid-related imaging abnormalities.

From a scientific perspective, this adds to an already substantial body of evidence suggesting that amyloid accumulation, on its own, does not explain the disease process. It may be part of the picture, but it is not the engine driving it.

And yet, the field has remained heavily focused on this single pathway.

When a hypothesis becomes a lens

Research tends to follow what is measurable, fundable, and already established. Over time, this can narrow the lens rather than expand it.

Amyloid has become that lens. As Karl Herrup argues in his book, once a hypothesis becomes dominant, it can begin to shape not just what is studied, but how results are interpreted and what gets funded next.

The result is that vast resources have been invested in understanding and modifying amyloid biology, while other avenues have received comparatively less attention. We have learned a great deal about amyloid itself, but we are not significantly closer to preventing or reversing the condition that matters most to patients, which is cognitive decline.

This is not unusual in science. Once a model becomes dominant, it shapes the direction of funding, research questions, and even how people interpret results.

A similar pattern is now emerging with another biomarker, p-tau.

Tau is a normal protein that, under certain conditions, becomes altered and associated with the tangles seen in Alzheimer’s pathology. Higher levels of p-tau are linked with increased risk, but again, association does not establish causation. Many individuals have elevated levels without clinical symptoms.

As with amyloid, the risk is that a marker becomes mistaken for the mechanism.

What does influence the disease process?

This is where the picture becomes more interesting.

There are factors that sit upstream of both amyloid and tau, influencing the environment in which brain cells function or fail. One of the most studied is homocysteine, a marker of methylation and B vitamin status.

Unlike amyloid, intervention trials have shown that homocysteine influences outcomes. In the VITACOG study, lowering elevated homocysteine with targeted B vitamins significantly slowed the rate of brain atrophy in individuals with mild cognitive impairment, with corresponding effects on cognitive decline. This is much closer to what we would describe as a disease-modifying effect (3,4). It also raises questions explored in Apparently healthy but diagnosed with Alzheimer’s about whether current diagnostic models are identifying true disease drivers or simply biomarkers.

That does not mean homocysteine is the only cause. It is one piece of a larger system. But it illustrates an important point. When you influence the underlying biology of the brain, rather than a downstream marker, you begin to see meaningful change.

For more on this approach, see our article on early diagnosis of Alzheimer’s: amyloid protein vs homocysteine testing.

A systems problem, not a single cause

Alzheimer’s does not behave like a single-cause disease.

It is better understood as the result of multiple interacting processes. These include inflammation, oxidative stress, insulin resistance, mitochondrial dysfunction, and impaired methylation, among many others (5). Each of these affects how brain cells are built, maintained, and powered.

Individually, they may not be sufficient to cause disease. Together, they can create the conditions in which the brain becomes vulnerable.

This is closer to how we understand most chronic conditions. Not as a single fault, but as a convergence of pressures that eventually exceed the system’s ability to compensate. A more useful way to think about it is not as one switch flipping, but as several dials turning in the wrong direction at the same time.

Why this matters

If we continue to focus primarily on downstream markers such as amyloid or p-tau, we risk missing the broader picture.

If instead we look at the upstream drivers, the factors that influence brain structure, function, and energy supply, we open up a different set of possibilities. Not just for treatment, but for prevention.

These are not fringe ideas. They are part of a growing shift in how Alzheimer’s is being understood, questioned, and re-examined. Researchers like Karl Herrup are helping to bring that conversation into the open, challenging long-held assumptions and asking more useful questions about what truly drives the disease.

It’s a conversation that is only just beginning to reach wider audiences.

This is exactly what we’ll be exploring at Alzheimer’s Prevention: New Frontiers conference, where leading researchers and clinicians will come together to look beyond single-cause models and towards a more complete understanding of brain health and cognitive decline.

Is prevention the real solution?

The prevailing model in medicine has been to identify a single cause and target it with a treatment. That works well for some conditions. It is less suited to complex, multifactorial diseases like Alzheimer’s.

A systems-based approach asks a different question.
What combination of factors leads to decline, and how do we shift that combination in the opposite direction?

This is the approach we take at Food for the Brain. By combining cognitive testing with blood testing and lifestyle information, it becomes possible to see patterns, not just isolated variables. Over time, this allows us to understand what drives resilience as well as risk.

It is likely that we will not find a single primary cause of Alzheimer’s. What we may find is something more useful: a set of modifiable factors that, together, determine whether the brain maintains function or begins to decline.

In that sense, prevention may not just be part of the solution.

It’s the solution.

Find out more with Alzheimer’s: Prevention is the Cure book here

Learn more about our Alzheimer’s Prevention: New Frontiers Conference here.

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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.

Related reading

Apparently Healthy, but Diagnosed with Alzheimerʼs? 
Why “Normal” Vitamin D Levels May Not Be Protective for Women’s Brains
Early Diagnosis of Alzheimer’s – Amyloid Protein vs Homocysteine Testing
‘My Relative Has Memory Problems, Possibly Dementia. What Do You Recommend?’
Homocysteine & Alzheimer’s Disease (2002)

How To Keep Your Brain Young with Antioxidants?

Being alive is a balancing act between making energy by combusting glucose with oxygen and generating ‘oxidant’ exhaust fumes that must then be neutralised. This process, known as oxidative stress, is a key contributor to ageing. Over time, if oxidants outpace your body’s ability to disarm them, damage accumulates in cells and tissues, including the brain.[8]

The brain is particularly vulnerable. It consumes a high proportion of the body’s oxygen, is rich in fats that are susceptible to oxidation, and has relatively limited antioxidant defences compared with other tissues. This makes maintaining an effective antioxidant defence system essential for long-term cognitive health.

However, this process is not fixed. You can influence it. Improving your intake of antioxidants and polyphenols, and supporting your body’s internal defence systems, can help shift the balance and support brain resilience over time.

To explore this idea further, watch the film ‘Keeping Your Brain Young with Antioxidants’ below.

The Science Behind Eating the Rainbow

You’ve heard it before, but the science behind it matters.

Different colours in plant foods reflect different polyphenols and antioxidant compounds, each with distinct biological effects. These compounds do more than just neutralise oxidants. Many also act as signalling molecules, influencing inflammation, blood flow, and cellular pathways linked to brain function and ageing.[9]

Mustard and turmeric, for example, are strong yellows. Dijon mustard is great, with no added sugar, and traditional English mustard is also beneficial. Turmeric, rich in curcumin, can be added to steam-fries, curries, or soups, grated into a tea, and even used in a turmeric latté.

Bright oranges such as butternut squash, sweet potato, and carrots provide carotenoids that support cellular protection. Tomatoes are particularly rich in lycopene, associated with reduced oxidative damage. Strawberries are a lower glycaemic fruit option, and peppers of all colours are rich in vitamin C, which plays a central role in antioxidant recycling.

Anything purple, magenta, or blue is especially valuable. From beetroot to blueberries, blackberries, and raspberries, these foods are rich in anthocyanidins, a class of polyphenols associated with improved vascular and cognitive function.

Strong greens remain foundational. Spinach, kale, Brussels sprouts, broccoli, watercress, rocket, asparagus, and green beans all contribute a wide spectrum of antioxidants, minerals, and phytonutrients that support detoxification and cellular defence.

Eating the rainbow is not a nice idea. It’s an essential part of upgrading and protecting your brain at any age.

The Best Fruits and Vegetables for Brain Health

But are there any particular vegetables or fruits that pack the biggest punch as far as polyphenols and antioxidants are concerned? Or, if you know you can’t or don’t like to eat a huge variety of fruit and veg, are there particular ones to focus on eating to get the most benefit?

Foods that are high in ‘polyphenols’, which refers to the structure of plant-based compounds, seem especially beneficial for protecting your brain. You might have heard of flavonoids in berries, quercetin in red onions, anthocyanidins in blue and red foods, and isoflavones in beans. These are all examples of polyphenols. Herbs and spices such as peppermint, basil, oregano, cumin, and curcumin in turmeric contain high levels of polyphenols and potent antioxidants.

But there are other criteria by which to judge a plant, including its ability to influence pathways linked to cellular ageing. Certain polyphenols, such as resveratrol, interact with sirtuin pathways involved in cellular repair and longevity.[10] For example, olives, blueberries, and kale support these processes.

Then there’s a group of compounds called ‘salvestrols’, generally only found in organic fruit, vegetables, herbs, and spices, which turn out to be anti-cancer.[1] They’re produced in plants as part of their self-defence system against invaders such as fungi. If the plant is sprayed with fungicides, it won’t produce them.

Taking all these factors into account, including the GL, antioxidants, polyphenols, salvestrols, and sirtuin-related activity, these are the dozen best-rated fruits and vegetables. (This list is not definitive. More and more research continues to reveal the healing power of nature’s fruits and vegetables.)

So, if eating the ‘rainbow’ feels like too much pressure or is difficult to achieve, think about incorporating some of the above into your meals each day.

Our Top 13 to Help Keep Your Brain Young

Top Up Brain-Friendly Antioxidant Nutrients: Consider Supplementation

Antioxidants Work as a Network

Much like dementia prevention is a combination of the 8 domains, which all influence each other, antioxidants are part of a network keeping you healthy.

A number of key vitamins, as measured in food and in the blood, do correlate with decreased dementia risk. This is hardly surprising, since the brain is made of complex fats that can easily be damaged by oxidants. It makes sense that having a high intake of antioxidants would protect the brain from damage. Antioxidants disarm oxidants by teamwork. You need a combination of nutrients, not just vitamin C or vitamin E.

Evidence for Antioxidant Protection

A recent meta-analysis of all studies on factors that could prevent Alzheimer’s, by one of our Scientific Advisory Board members, Professor Jin Tai Yu of Fudan University in Shanghai, China, shows that ‘either a high vitamin E or C intake showed a trend of attenuating risk by about 26%’, making these nutrients ‘grade 1’ top level prevention risk factors.[2]

A study of 4,740 Cache County, Utah, older residents found that those supplementing both vitamin E and C cut their risk of developing Alzheimer’s by two thirds. A trend toward lower Alzheimer’s risk was also evident in those who took vitamin E supplements together with multivitamins containing vitamin C, but there was no evidence of a protective effect in those taking only vitamin E or vitamin C supplements alone, with multivitamins alone, or with vitamin B-complex supplements. Lowest risk was reported in those supplementing at least 1000 mg a day of vitamin C together with at least 1000 IU a day of vitamin E.[3]

However, vitamin E on its own doesn’t seem to work. In a double-blind study, people with mild cognitive impairment were randomly assigned to receive 2000 IU a day of vitamin E or placebo for three years. There were no significant differences in the rate of progression to AD between the vitamin E and placebo groups at any point.[4]

Building Your Antioxidant Defences

Your best bet is probably to both eat a broad spectrum of antioxidants and also supplement them. The older you are, the more you are likely to need. Key antioxidants are:

Vitamin A, C and E – associated with reducing Alzheimer’s risk

Lipoic acid – protects the memory-friendly neurotransmitter acetylcholine and dampens brain oxidation and inflammation.[5]

Glutathione[6] or N-acetyl cysteine[7] (NAC) – protects the brain and improves methylation, thus having potential in dementia prevention.

It doesn’t really make a lot of sense to give one without the others. All those listed above, vitamin C, E, glutathione, N-acetyl cysteine, Coenzyme Q10 and resveratrol, work together. There are many other team player ‘cousins’, from B vitamins to minerals such as magnesium, zinc and selenium.

The first step is to eat ‘whole’ foods, especially fresh plant foods that are more likely to contain these kinds of nutrients. However, there are some nutrients, such as vitamin C, for which just eating whole foods doesn’t guarantee you are achieving optimum nutrition.

Most nutritional therapists supplement extra vitamin C, and some supplement an all-round antioxidant supplement providing the nutrients listed above. There is very good logic, and supporting evidence, to do this, especially if you’re over 50 years old, even if there isn’t yet that definitive ‘randomised placebo controlled trial’.

Other key antioxidant nutrients include:

Vitamin A, C and E – associated with reduced Alzheimer’s risk

Lipoic acid – supports mitochondrial function and reduces oxidative stress and inflammation.[5]

Glutathione or N-acetyl cysteine (NAC) – supports detoxification, antioxidant recycling and methylation, with potential relevance for cognitive ageing.[6][7]

Coenzyme Q10 and resveratrol – support cellular energy and protection

There are also important supporting nutrients, including B vitamins, which contribute to methylation and help regulate homocysteine, a compound associated with oxidative stress and cognitive decline when elevated.[12]

Why Food Comes First but Supplements May Still Be Needed

We are Food for the Brain, so the first step is always to eat whole foods, focusing especially on fresh plant foods that are naturally rich in antioxidants and polyphenols.

However, achieving optimal levels of certain nutrients through diet alone is not always guaranteed. Factors such as soil depletion, food storage, genetics, individual absorption, age, and increased physiological demand all play a role.

For this reason, targeted supplementation, particularly for nutrients such as vitamin C and those involved in the antioxidant network, may be beneficial. There is strong rationale, and supporting evidence, for this approach, especially in individuals over 50 or those with increased oxidative load. Read more about supplementation here.

From General Brain Health Advice to Personalised Insight

Why Antioxidant Needs Differ and Why Testing Matters

Eating a diet rich in colourful plant foods is a powerful place to start. But the real question is whether your unique body has the antioxidant capacity to meet your current level of demand.

Or, said another way, how do you know if you are eating enough to protect your brain and your future?

Oxidative stress is influenced by far more than diet alone. Age, stress, environmental toxins, blood sugar balance, genetic variations, nutrient status, and individual biochemistry all play a role. Two people can eat similarly and have very different levels of oxidative damage and antioxidant protection.

This is where testing becomes valuable.

One of the most informative markers is glutathione, often referred to as the body’s master antioxidant. It sits at the centre of your antioxidant defence system, helping to neutralise oxidative damage and recycle other antioxidants. If levels are low, it can indicate that your overall antioxidant capacity is under strain.

Rather than guessing whether you are getting enough antioxidant support, testing allows you to see what is actually happening inside your body. (Historically, glutathione has been hard to test, but we developed new technology with our lab partners to now be able to do this accurately with an at home finger prick blood test.)

Understanding Your Brain Health More Clearly

The DRIfT 5-in-1 test shows you what is actually happening inside your body, across the key drivers of cognitive decline, including oxidative stress, inflammation, blood sugar balance, nutrient status, and essential fats. It moves you beyond general advice and highlights exactly where your biggest risks and opportunities lie.

If your focus is antioxidant capacity, testing glutathione offers direct insight into whether your body is under oxidative strain and how well your defence system is functioning. Find out more here.

Alongside this, our free Cognitive Function Test provides a practical way to track how your brain is performing today, while contributing to ongoing research into what truly works in preventing cognitive decline.

Understanding your results allows you to move from general advice to a more targeted, personalised approach, so you can support your brain with greater precision and confidence.

When you join COGNITION and become a FRIEND, you get access to our new Digital education platform and our new COGNITION programme. You can also register FREE for both our monthly guest speaker webinars and our monthly live COGNITION Coaching – this is an hour live with our Food for the Brain health coaches and there is a Q&A at the end (you also get access to the past coaching workshop recordings).

On April 22nd April, our COGNITION Coaching Workshop is all about antioxidants and attendees will get a mini-ebook on antioxidants and 2 delicious, anti-oxidant rich recipes. You can become a FRIEND by clicking the link below:

Food for the Brain is a not-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.

Dr Tommy Wood: Why Brain Health Needs a Systems-Based Approach

Dr Tommy Wood brain health research shows that we now know more than ever about protecting the brain, yet many people still feel overwhelmed by disconnected advice.

A headline about blood sugar here. A podcast on omega-3 there. A post about sleep, a study on exercise, a warning about stress.

Useful, yes. But also fragmented.

What Dr Tommy Wood brain health research offers is something more valuable than another isolated tip. He brings a framework.

As Head of Research at Food for the Brain, Associate Professor of Pediatrics and Neuroscience at the University of Washington, and author of the forthcoming book The Stimulated Mind, Tommy brings something rare to this field. He helps connect the dots. His work focuses on how brain health is shaped across the lifespan and why protecting cognitive function means thinking in systems, not silos.

Dr Tommy Wood Brain Health Framework

One of the reasons brain health can feel confusing is that it is often presented as a list:
A long list of risk factors. Nutrients to take, habits to adopt, or a long list of things to avoid.

But the brain does not work like a checklist: it works as a living, dynamic system. It responds to what it is supplied with, how it is used, and whether it has the conditions it needs to recover and adapt.

That is the core idea behind a systems-based approach to brain health.

Instead of asking “What is the one thing that protects the brain?”, it asks three bigger questions:

Does the brain receive enough oxygen, nutrients and stable energy to function well?
How well is it being stimulated to stay active, adaptable and resilient?
Are the foundations for repair and recovery in place, such as good sleep, stress regulation and metabolic health?

When you look at brain health this way, something important changes.

Many people understandably hope for a “magic bullet”. One supplement. One diet. One breakthrough drug that protects the brain.

But science tells a different (more hopeful) story. Cognitive resilience is shaped by the interaction between many systems in the body. Blood flow, nutrient status, sleep, movement, learning, stress and social connection all influence how the brain functions and adapts.

The encouraging part is that this gives us many entry points for change. You do not have to get everything perfect, and small improvements across several areas can work together to create meaningful protection for the brain over time.

That is why a systems-based approach is not more complicated. In practice, it is far more empowering.

Why this matters for prevention?

One of the most important insights in Tommy’s work is that cognitive decline does not happen in isolation.

The brain changes in response to how we live. Blood flow, nutrient status, movement, learning, sleep, stress and social connection all shape how the brain ages and how resilient it remains.

This is also why Tommy’s forthcoming book, The Stimulated Mind, focuses on the interaction between stimulation, sleep and nutrient supply as key drivers of lifelong brain health.

This perspective is closely aligned with the mission of Food for the Brain. For years we have been communicating that dementia risk is not fixed. By understanding and addressing modifiable factors across the lifespan, it is possible to protect your mind and keep the brain healthier for longer.

Tommy’s leadership as Head of Research helps bring greater scientific clarity to this systems-based approach to prevention.

Watch: A systems-based approach to cognitive function

If you want to hear Tommy explain this approach in more depth, his lecture from the Upgrade Your Brain Conference is one of the clearest introductions we have shared.

Watch the lecture below.

What Tommy offers is not another list of things to do. It is a framework. A way to understand why so many different factors matter and how they fit together.

Learn More About Dr Tommy Wood Brain Health Research

If this approach resonates with you, Tommy will be going deeper in our upcoming webinar, How to Keep Your Brain Young.

In this session he will explore the science of cognitive resilience and share practical ways to stimulate the brain, support long-term brain health and reduce lifetime dementia risk.

Food for the Brain will host the webinar on 19th March 2026 at 6 pm GMT.

Tommy’s new book is available to pre-order

Tommy’s new book, The Stimulated Mind, is also available to pre-order now.
In it, he explores how the brain develops, adapts, and stays resilient across the lifespan, and why everyday factors such as movement, learning, sleep, nutrition, and social connection play such an important role in shaping long-term brain health.

Pre-order your copy today before the book releases on 26th March 2026.

Final thought

For many people, the challenge with brain health is not a lack of information. It is knowing where to start.

When advice comes as scattered tips, nutrients, tests, and lifestyle changes, it can feel difficult to turn good science into clear action.

What Tommy’s work offers is a framework: a way of understanding how the different pieces of brain health fit together and why small changes across several areas can have a powerful cumulative effect.

At Food for the Brain, this systems-based approach sits at the heart of COGNITION, our brain upgrade programme.

COGNITION helps you understand your personal risk factors, learn the most important steps to protect your brain, and put them into practice with guidance and support.

The programme has recently been upgraded and is now available globally for just £5 per month or £50 a year, making it accessible to anyone who wants to take their brain health seriously.

If Tommy’s lecture resonates with you, COGNITION is the natural next step.

Because protecting your brain is not about doing everything perfectly.

It is about understanding the system and taking the next right step.

Food for the Brain is a not-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.

The Biggest Myths About Alzheimer’s – And What the Science Actually Shows

Alzheimer’s disease is one of the most feared diagnosis of modern life. And where there is fear, myths flourish. Many of the biggest myths about Alzheimer’s have become widely accepted beliefs. We are told it is purely genetic, that it is an inevitable part of ageing, and that the main hope lies in new drugs targeting amyloid in the brain.

The science tells a far more complex and, importantly, far more hopeful story.

Myth #1 in the biggest myths about Alzheimer’s: ‘It’s all in your genes’

When Alzheimer’s runs in families, it is natural to assume destiny is fixed. Both your grandmothers had it, so you assume you will too.

Yet fewer than 1% of cases are caused by rare deterministic mutations in APP, PSEN1 or PSEN2 genes that lead to early-onset familial Alzheimer’s disease [1].

The vast majority of Alzheimer’s cases are late-onset and multifactorial. That means risk is shaped by multiple influences across a lifetime.

What about APOE4?

Celebrities like Chris Hemsworth have put the APOE4 gene on the map and into the public sphere and it is the strongest common genetic risk factor for late-onset Alzheimer’s. Having one copy increases risk; two copies increase it further [2]. But it does not determine outcome, as many APOE4 carriers never develop dementia. Many people with Alzheimer’s do not carry APOE4.

Genes influence vulnerability but they do not dictate your future.

APOE4 affects lipid transport, inflammatory signalling and neuronal repair. These processes are influenced by metabolic health, vascular function, nutrient status, sleep, stress physiology and lifestyle.

One of the most important things to remember is that gene expression is not static, as genes respond to the environment they are in.

The most important question is not necessarily ‘How do I check my genes?’ The question is ‘What environment are your genes operating in?’ Because you cannot change your genes but you can influence how they function and are expressed.

Myth #2 in the biggest myths about Alzheimer’s: ‘Nothing can be done’

This is the most damaging myth of all.

The 2020 Lancet Commission concluded that around 40% of dementia cases worldwide are attributable to modifiable risk factors [3]. The 2024 update increased that estimate to approximately 45% [4].

Nearly half of all cases.

And this is mainstream consensus. (Read more about the Alzheimer’s Prevention Expert Group’s APEG response to this recent Lancet report here).

The identified risk factors include hypertension, diabetes, obesity, physical inactivity, smoking, depression, hearing loss and social isolation. Importantly, Alzheimer’s risk is not fixed, it develops gradually over decades.

However, many researchers (ourselves included) believe even 45% may underestimate the true preventable proportion.

A large UK Biobank analysis published in the journal Nature Human Behaviour modelled a broader range of modifiable factors and estimated that up to around 73% of dementia cases could be attributable to modifiable influences [8]. Professor David Smith of Oxford University, co-author of that study, member of our Scientific Advisory Board, and lead investigator of the VITACOG trial, has suggested this may still be conservative, as certain blood biomarkers were not included in the modelling.

Whether the true figure is closer to 45% or 73%, the direction of evidence is consistent.

A large proportion of dementia and Alzheimer’s is preventable and you can modify your risk with simple changes.

Why biology supports prevention

Alzheimer’s develops through interacting processes such as impaired glucose metabolism, vascular dysfunction, inflammation and elevated homocysteine.

Raised homocysteine, reflecting impaired methylation and B vitamin status, is associated with increased dementia risk and accelerated brain atrophy [5].

In the VITACOG trial, homocysteine-lowering B vitamins significantly slowed whole-brain atrophy in people with mild cognitive impairment [6]. The benefit was strongest in those with adequate omega-3 status [7].

That is structural brain change.

(When compared to anti-amyloid drug trials, which show modest slowing of decline in already symptomatic patients, VITACOG demonstrated slowing of brain shrinkage itself in an at-risk group.)

Once significant neuronal loss has occurred, reversal is unlikely, but years before diagnosis, measurable risk is accumulating and that is where prevention has its power.

Myth #3 in the biggest myths about Alzheimer’s: ‘It has a single cause‘

The reductionist model searches for one target and one solution.

Alzheimer’s reflects the interaction of multiple biological systems:

Glucose regulation
Vascular health
Lipid transport
Inflammation
Oxidative stress
Methylation
Sleep and stress regulation
Hormonal balance

People arrive at cognitive decline through different combinations of biological drivers. For some, insulin resistance may be central. For others, vascular stiffness and hypertension. In others, chronic inflammation and elevated homocysteine may play a key role. The destination may look similar, but the route is not.

This systems view explains why targeting one downstream marker, such as amyloid, yields modest slowing. Correcting multiple upstream drivers is biologically more plausible for meaningful long-term risk reduction.

Watch the video below to learn how Food for the Brain uses a systems-based approach.

Myth #4 in the biggest myths about Alzheimer’s: ‘It’s inevitable with ageing’

Age increases risk. However, that is only part of the story.

There are many individuals in their 80s and 90s with preserved cognition. The difference often lies in lifelong vascular, metabolic and lifestyle patterns, also known as patterns for prevention.

It is clear from what you have read so far that this is not an inevitable part of getting older. With the right knowledge and habits, it is something most people can avoid.

And that is why Food for the Brain exists, because not enough people know this and not enough people know what action they need to take to protect their brain.

A More Accurate Framework

Ageing is not the enemy. It is a privilege denied to many.

The goal is not to avoid growing older. It is to protect the brain as we do.

Alzheimer’s is not a single event. It reflects decades of interacting biological stress: metabolic strain, vascular change, inflammation and nutrient imbalance. These processes build slowly and often silently.

By the time symptoms appear, significant damage has already occurred.

The science is clear that a substantial proportion of dementia risk is modifiable [6,10]. That does not mean guarantees. It means opportunity.

You cannot change your genes and you cannot stop the passage of time.

Yet, you can influence how your brain responds to both.

And you can start today!

Complete the Cognitive Function Test

Gain personalised insight into your current cognitive performance and identify potential areas of vulnerability early.

Measure your biomarkers

Order our at-home blood test to assess homocysteine, omega-3 status, and other key markers linked to long-term brain resilience.

Join COGNITION

Our six-month brain upgrade programme provides structured guidance, accountability and expert support to help you translate knowledge into meaningful and lasting change.

Prevention is possible. It begins with measurement, and it progresses with action.

Food for the Brain is a not-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.

Why “Normal” Vitamin D Levels May Not Be Protective for Women’s Brains

Science now recognises Vitamin D as far more than a bone-health nutrient. Over the past decade, it has become increasingly clear that vitamin D acts as a hormone regulator, playing an important role in brain health, immune regulation and inflammation, especially when considering optimal vitamin D levels for women’s brains.

What is discussed far less, is a more nuanced question…

If vitamin D matters for the brain, how much is actually enough and do vitamin D levels differ for women?

A growing body of research links lower vitamin D status with a higher risk of cognitive decline and Alzheimer’s disease. Yet most guidance still relies on population-based “normal” ranges that were never designed to protect the brain. This raises an important prevention question for women, who already carry a higher lifetime risk of Alzheimer’s disease.

What the research shows

A systematic review and meta-analysis in 2025 by Li et al. examined the relationship between circulating vitamin D levels and Alzheimer’s disease risk across multiple observational studies (1).

The findings were consistent:

• Lower vitamin D levels link to a higher risk of Alzheimer’s disease.
• Risk increased progressively as vitamin D levels declined
• Researchers observed this association across different populations and study designs.

Crucially, the authors did not claim that vitamin D deficiency causes Alzheimer’s disease. Instead, vitamin D status appears to track biological vulnerability in the brain and reflects processes such as neuroinflammation, immune dysregulation and vascular dysfunction, all recognised contributors to cognitive decline.

This distinction matters for prevention.

Why these findings matter particularly for women

Women account for around two thirds of Alzheimer’s diagnoses worldwide. Longevity alone cannot explain this difference.

Across midlife and later life, women experience biological changes that alter how the brain responds to metabolic, inflammatory and hormonal stress. The menopausal transition is a key inflection point. Declining oestrogen and progesterone influence immune signalling, cerebral blood flow and brain energy metabolism, all of which intersect with established dementia risk pathways (3). This helps explain why midlife can be a turning point for brain health in women, even when blood test results appear “normal”.

Vitamin D functions as a hormone-like regulator, with receptors widely distributed throughout the brain and immune system. Its actions include modulation of inflammatory responses, immune balance and neuronal protection. Hormonal changes appear to influence how effectively vitamin D signalling is utilised at a tissue level. This is supported by experimental and clinical research showing interactions between oestrogen, vitamin D receptors and immune signalling, although this is not always directly measured in large population studies. In practical terms, this means that a vitamin D level considered “normal” for the general population may not confer the same degree of neuroprotection in the ageing female brain.

This does not mean vitamin D requirements are definitively higher for every single woman, or that everyone should take high-dose supplementation. Excessive intakes via supplementation over time can be harmful, which is why context, testing and appropriate dosing matter. 

Prevention works best when it’s personal, based on what’s happening in your own brain and body, not just what’s considered “normal.”

The problem with “normal” ranges for vitamin D for women’s brains

Researchers established vitamin D reference ranges primarily to prevent overt deficiency-related disease, particularly rickets and osteomalacia. They did not design these ranges to define optimal levels for long-term brain resilience.

Population reference ranges do not account for factors that strongly influence dementia risk, including:

Chronic low-grade inflammation
Insulin resistance and blood sugar dysregulation
Oxidative stress (see our explainer video here)
Hormonal transitions across midlife
Genetic variation in vitamin D metabolism and receptor activity

As a result, vitamin D levels that fall within the laboratory “normal” range may still exist within a biological environment that favours cumulative brain damage over time. This limitation is not unique to vitamin D. It reflects a broader problem with single-nutrient or single-cause thinking in Alzheimer’s prevention.

Vitamin D does not act alone in protecting women’s brains

Vitamin D is not an isolated lever in brain health. Low vitamin D status frequently clusters with other modifiable biological risk factors, including:

• Low omega-3 fatty acid status
• Raised homocysteine, reflecting impaired B vitamin-dependent methylation, a process essential for maintaining brain cells
• Poor blood sugar control
• Reduced antioxidant capacity, including glutathione availability

Each of these factors independently links to cognitive decline. More importantly, they interact within the brain.

Alzheimer’s disease does not arise from a single deficiency, a single gene or one pathological protein.
It reflects the cumulative impact of multiple biological systems drifting out of balance over years or decades. This is why interventions that target a single marker so often produce disappointing results.

Prevention requires a broader, systems-based view.

Once you see vitamin D in this broader context, it becomes clear why testing a single marker in isolation can only ever give partial answers.

From nutrients to prevention systems

Testing vitamin D alone can identify a deficiency, but it cannot tell you whether the brain’s key protective systems are functioning together.

A prevention-led approach asks different questions:

How well is inflammation being regulated?
Are brain cell membranes supported by sufficient essential fats?
Is methylation, the nutrient-dependent process that supports DNA repair, neurotransmitter balance and brain structure, functioning effectively?
To what extent is blood sugar quietly damaging brain neurons over time?

These are not abstract concepts.

They are measurable, modifiable drivers of dementia risk that we assess through our at-home DRIfT blood test.

A smarter way to assess brain health

Many people reading this will have been told their vitamin D is “fine”. They may spend time outdoors, eat well, and still feel tired, foggy or not quite themselves. The problem is not that vitamin D doesn’t matter. It’s that a single number rarely tells the full story.

This systems-based understanding underpins our work at Food for the Brain. It is the heart of prevention.

Prevention is not about chasing one “perfect” nutrient level or one lifestyle change. 

It is about understanding how your body works as one connected system and acting early enough to change the trajectory.

If you want to begin supporting and upgrading your brain today:

Complete the Cognitive Function Test today if you haven’t done so yet.
It is free to everyone, validated and provides personalised insights into your current brain health.

Order your at-home DRIfT blood test to assess the key biological drivers of cognitive decline, including vitamin D, omega-3, homocysteine, blood sugar control and antioxidant status. Together, these results give you the information you need to move from awareness to meaningful prevention.

Food for the Brain is a not-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.

Li X, et al. The relationship between vitamin D levels and Alzheimer’s disease: a systematic review and meta-analysis.

Alzheimer’s Association. 2023 Alzheimer’s Disease Facts and Figures.

Lancet Commission on Dementia Prevention. Livingston G, et al. Dementia prevention, intervention, and care: 2020 report.

Why Gut Health Matters for Brain Health More Than You Think

Why Some Brains Improve and Others Don’t

Many people are doing more than ever to protect their brain. They eat well. Take supplements. Exercise. Stay mentally active.

Yet outcomes vary dramatically.

Some improve. Others stall. A few decline despite doing everything “right”.

The missing question is not what else to add, but what environment those interventions are landing in.

Cognitive decline rarely stems from one isolated failure. It emerges when the body’s internal environment no longer supports protection, repair, and resilience. This systems-based understanding underpins the work of Food for the Brain, and explains why gut health plays a central role in our COGNITION brain upgrade programme.

The terrain model of brain health

In medicine, there is a long-established principle that disease does not arise from a trigger alone, but from the biological environment in which that trigger operates. This is often described as the terrain.

From a brain health perspective, terrain includes inflammatory load, metabolic health, immune balance, nutrient availability, and cellular repair capacity. These systems interact constantly. When they stay in balance, the brain shows remarkable resilience. When they become disrupted, vulnerability increases.

Neurodegenerative conditions, including Alzheimer’s disease, are now understood to arise from multiple interacting biological pressures rather than a single pathological process. Many of these systems are shaped upstream by gut related processes.

The gut as a regulator, not a root cause

The gut is often discussed as if it were a standalone digestive organ. In reality, it plays a regulatory role in shaping systemic inflammation, metabolic function, and immune signalling.

When gut barrier integrity is compromised, bacterial components such as lipopolysaccharides can enter circulation. This process increases immune activation and drives chronic low-grade inflammation, a state strongly associated with insulin resistance and cognitive decline [1,2].

In this context, gut dysfunction is not “causing” brain disease. It is influencing the conditions in which brain protection and repair either succeed or struggle.

Why prevention struggles in an inflamed system

Brain health interventions that we talk about here at Food for the Brain do not operate in isolation. Their effectiveness depends on the biological environment in which they are applied.

This is particularly clear in nutritional research.

B vitamin supplementation has been shown to slow brain atrophy, but only in individuals with raised homocysteine levels and a metabolic environment that allows normal methylation processes to function [3]. Similarly, omega 3 fatty acids support neuronal membrane structure and signalling, yet their cognitive benefits are reduced in the presence of inflammation and insulin resistance [4].

Inflammation interferes with digestion, absorption, transport, and cellular uptake of nutrients. Pro inflammatory cytokines also impair intracellular metabolic pathways, shifting the body toward defence rather than repair. In this terrain, even well evidenced interventions may have limited effect.

The same principle applies to lifestyle strategies. Physical activity, cognitive stimulation, and stress reduction are all protective, but their impact is blunted when inflammatory and metabolic pressures remain unaddressed. That is why in COGNITION we target all 8 modifiable nutrition and lifestyle factors, so that you are not just targeting a specific nutrient but you are changing the environment.

Microbes, inflammation, and brain vulnerability

Human studies consistently show that individuals with cognitive impairment or Alzheimer’s disease have altered gut microbiome profiles alongside higher levels of systemic inflammatory markers [5].

This does not demonstrate that microbes cause dementia. What it does show is that microbial imbalance contributes to inflammatory load, which in turn increases brain vulnerability.

Over time, this vulnerability can translate into accelerated cognitive decline.

For this reason, the COGNITION brain upgrade programme actively addresses gut health as one of eight modifiable factors that influence dementia risk. Gut microbes actively shape the internal environment in ways that can either accelerate neurodegeneration or help slow it.

The metabolic bridge between gut and brain

The gut also plays a critical role in metabolic regulation.

Chronic gut driven inflammation worsens insulin resistance, reducing glucose uptake by brain cells. Impaired brain glucose metabolism is a recognised feature of cognitive decline and has led some researchers to describe Alzheimer’s disease as a form of brain specific metabolic failure [6,7].

In this model, the gut is not peripheral. It contributes upstream to the metabolic conditions that determine whether the brain can access adequate fuel to function and repair.

Again, the implication is not that gut health alone determines brain fate. It is that brain health strategies are less effective when the metabolic and inflammatory terrain is unfavourable.

Why Brain Health Advice Works for Some People and Not Others

A terrain based perspective offers something often missing from prevention conversations.

Understanding.

When people follow advice carefully and still do not improve, clinicians too often frame the explanation as lack of compliance or genetics. Systems thinking offers a different interpretation.

The tools may be appropriate but the environment may not yet support repair.

This reframes prevention as a personalised process rather than a universal checklist. Understanding an individual’s internal terrain helps identify where effort should go.

This is why Food for the Brain offers two complementary forms of assessment: the free, validated Cognitive Function Test and optional at home blood testing to assess key modifiable risk markers such as homocysteine, omega 3 status and glutathione.

The answer is not found in one nutrient

Viewing brain health through a terrain lens shifts prevention away from adding isolated solutions and toward restoring balance across systems.

The future of brain health does not lie in targeting one nutrient, one habit, or one molecule.

It lies in creating an internal environment where protection, repair, and resilience are possible.

Brains do not fail because one thing goes wrong. They decline when the terrain no longer supports them.

And that terrain forms quietly and cumulatively long before symptoms appear.

Next Steps

Learn more about how gut health impacts brain health in our upcoming webinar here
Complete the FREE, validated Cognitive Function Test today so you can get instant insight into your current brain health status
Order your at home blood test here to get more personalised data on your body and contribute to our on going research

Food for the Brain is a not-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.

Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, et al. Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes. 2007;56(7):1761–72.
Hotamisligil GS. Inflammation and metabolic disorders. Nature. 2006;444(7121):860–7.
Smith AD, Smith SM, de Jager CA, Whitbread P, Johnston C, Agacinski G, et al. Homocysteine-lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment. Proc Natl Acad Sci U S A. 2010;107(31):14187–92.
Jernerén F, Elshorbagy AK, Oulhaj A, Smith SM, Refsum H, Smith AD. Brain atrophy in cognitively impaired elderly: the importance of long-chain omega-3 fatty acids and B vitamin status in a randomized controlled trial. Am J Clin Nutr. 2015;102(1):215–21.
Vogt NM, Kerby RL, Dill-McFarland KA, Harding SJ, Merluzzi AP, Johnson SC, et al. Gut microbiome alterations in Alzheimer’s disease. Sci Rep. 2017;7(1):13537.
Craft S. Insulin resistance and Alzheimer’s disease pathogenesis: potential mechanisms and implications for treatment. Arch Neurol. 2009;66(3):300–5.
de la Monte SM, Wands JR. Alzheimer’s disease is type 3 diabetes–evidence reviewed. J Diabetes Sci Technol. 2008;2(6):1101–13.