By Patrick Holford

Recently, the Telegraph reported: “Statins can reduce the risk of dementia among those who already have low cholesterol.” The article claimed that those on statins were less likely to develop dementia – even Alzheimer’s – and that low LDL cholesterol was somehow protective.

Frankly, this is dangerous misinformation.

Why? Because it contradicts robust scientific evidence that low cholesterol – particularly below 4 mmol/l – increases the risk for dementia. That’s hardly surprising when you consider that 25% of the cholesterol in your body is in your brain. Cholesterol is a vital component of neuronal membranes – it’s not just blood fat, it’s brain fuel.

And as for statins? There’s no credible evidence that they prevent dementia. Quite the opposite: the evidence points to statins lowering brain-essential cholesterol and raising dementia risk. So I asked cholesterol expert Dr Malcolm Kendrick for his take on the study in question.

His response was blunt but justified: “This study is horseshit. Here’s why…”

Dr Kendrick Key Critiques:

LDL measurement was vague. It’s unclear if they even measured LDL directly- most studies use the Friedewald formula, known to be wildly inaccurate, especially with high triglycerides or low HDL.

Only one measurement. LDL was recorded once at the study’s start – never again. That’s like measuring someone’s blood pressure once and claiming to predict their lifetime stroke risk.

Bizarre cohort overlap. Somehow, 170,174 participants were in both high and low LDL groups? That’s statistically and biologically nonsensical.

Alzheimer’s exclusion unexplained. Those with pre-existing Alzheimer’s were removed, but with no breakdown of their LDL levels – crucial missing data.

Propensity score manipulation. This “retrospective matching” excluded over 350,000 people, distorting the natural associations. Diabetes and hyperlipidaemia were artificially balanced between groups, masking real-world relationships.

Key confounder: statin timing. Participants were only included after being prescribed statins, meaning LDL levels were already artificially lowered. So “low LDL” here is post-drug, not natural. The entire premise collapses.

This study, like too many others published today, exemplifies what Drummond Rennie famously criticised:

“There is no study too fragmented, no hypothesis too trivial, no design too warped, no analysis too self-serving for it to be published.”

So what do we actually know? Here is an extract from Patrick’s new book – Alzheimers: Prevention is the Cure.

Cholesterol and the Brain – The Real Story

Your brain needs cholesterol. Low cholesterol (<4 mmol/l) is a clear risk factor for dementia. One biomarker study found that high homocysteine and low cholesterol were the best predictors of dementia risk【1】.

And what’s a common cause of low cholesterol in the elderly? Statins. These drugs have consistently failed to show benefits in preventing cognitive decline【2】.

This fits what we know genetically. The ApoE gene governs how cholesterol gets into neurons. Those with ApoE4 are less efficient at this – that’s why they’re more prone to cognitive decline.

It’s not high cholesterol itself that’s dangerous – it’s cholesterol mismanagement in the brain.

Yes, very high cholesterol (above 6.5 mmol/l) is statistically linked to increased dementia risk – but modest elevations, particularly with a healthy lifestyle, are not a problem【3】. And even that data is shaky. One meta-analysis of over a million people showed only a 14% increased dementia risk with “high” cholesterol. But the thresholds varied – some studies defined “high” as anything over 6.2 mmol/l【3】.

More importantly, people with higher cholesterol often eat more sugar, processed foods, and trans fats – all factors known to fuel inflammation and oxidative stress in the brain.

The Lancet Commission, which makes the anti-cholesterol case, even acknowledged this diet–dementia link: in a cohort of 94,184 Danes, poor diet predicted both high LDL and dementia risk【4】.

So maybe it’s not the cholesterol – it’s what comes with it.

Statins and the Hope for Vascular Dementia 

Originally, statins were hyped for vascular dementia – about 20% of all dementia cases – because of their supposed blood vessel–protective effects. But that theory has fallen flat. A Cochrane review found no benefit from statins for dementia prevention【6】.

And the best independent trial – not funded by drug companies – also found no cardiovascular benefit for statins in older adults【5】.

There’s no data supporting the notion that statins protect the brain. Yet the Lancet Commission listed “high cholesterol” as contributing 7% to dementia risk, which will no doubt spur even more statin prescriptions【4】.

The Optimum Nutrition Perspective

From an optimum nutrition standpoint, we view cholesterol differently.

If your total cholesterol is up to 6.5 mmol/l – but you have high HDL, low triglycerides, low homocysteine, and a healthy diet low in sugar and refined carbs – you’re not at risk. In fact, you’re likely protected.

One recent study showed that higher HDL in midlife predicted significantly lower future dementia risk【7】. Low HDL, not high total cholesterol, is a hallmark of metabolic syndrome – the precursor to diabetes, heart disease, and yes, dementia.

The evidence is clear: cholesterol is essential for brain health. Statins do not prevent dementia – and may contribute to cognitive decline by pushing cholesterol levels too low.

Instead of dumbing down the brain with unnecessary statins, we need to smarten up with nutrients that build brain health: omega-3 fats, phospholipids, B vitamins, and a low-sugar diet.

Doctors prescribing statins as dementia prevention are not only missing the mark – they may be making things worse.

Let’s change the narrative. Let’s put nutrition – not cholesterol fear – at the top of the brain health agenda. Find out more in Patrick’s new book – Alzheimer’s: Prevention is the Cure.

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.

References

1  Gong, Q., Xie, L., Bi, M., & Yu, L. (2021). A probability formula derived from serum indicators, age, and comorbidities as an early predictor of dementia in elderly Chinese people. Brain and Behavior 11, e2236. https://doi.org/10.1002/brb3.2236

2 Peters, R, Breitner, J, James, S, et al. Dementia risk reduction, why haven’t the pharmacological risk reduction trials worked? An in-depth exploration of seven established risk factors. Alzheimer’s Dement. 2021; 7:e12202. https://doi.org/10.1002/trc2.12202 

3 Wee J, Sukudom S, Bhat S, Marklund M, Peiris NJ, Hoyos CM, Patel S, Naismith SL, Dwivedi G, Misra A. The relationship between midlife dyslipidemia and lifetime incidence of dementia: A systematic review and meta-analysis of cohort studies. Alzheimers Dement (Amst). 2023 Mar 8;15(1):e12395. doi: 10.1002/dad2.12395. PMID: 36911359; PMCID: PMC9993469.

4  Kjeldsen EW, Thomassen JQ, Rasmussen KL, Nordestgaard BG, Tybjærg-Hansen A, Frikke-Schmidt R. Adherence to dietary guidelines and risk of dementia: a prospective cohort study of 94 184 individuals. Epidemiol Psychiatr Sci 2022; 31: e71. 

5  Han BH, Sutin D, Williamson JD, Davis BR, Piller LB, Pervin H, Pressel SL, Blaum CS; ALLHAT Collaborative Research Group. Effect of Statin Treatment vs Usual Care on Primary Cardiovascular Prevention Among Older Adults: The ALLHAT-LLT Randomized Clinical Trial. JAMA Intern Med. 2017 Jul 1;177(7):955-965. doi: 10.1001/jamainternmed.2017.1442. PMID: 28531241; PMCID: PMC5543335.

6  McGuinness B, Craig D, Bullock R, Passmore P. Statins for the prevention of dementia. Cochrane Database Syst Rev 2016;1: CD003160. 

7 Zhang X, Tong T, Chang A, Ang TFA, Tao Q, Auerbach S, Devine S, Qiu WQ, Mez J, Massaro J, Lunetta KL, Au R, Farrer LA. Midlife lipid and glucose levels are associated with Alzheimer’s disease. Alzheimers Dement. 2023 Jan;19(1):181-193. doi: 10.1002/alz.12641. Epub 2022 Mar 23. PMID: 35319157; PMCID: PMC10078665.