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experts comment on a prospective cohort study looking at adherence to the MIND diet (combined Mediterranean and blood pressure lowering diet) and longitudinal brain structural changes
Dr Mohammad Talaei, Lecturer in Life Course Epidemiology, Centre for Preventive Neurology, Wolfson Institute of Population Health, Queen Mary University of London, said:
For a very long time, the public and the scientific community have been interested in whether our diet can improve brain health. This study is one big step in that direction by using objective outcomes, thanks to brain imaging, and by using multiple assessments of diet and brain volume over a long period of time. On the one hand, without evidence from human experimental studies, it would be hard to use such findings to make decisive recommendations. On the other hand, observational evidence remains the most feasible source of knowledge for now, which is why improvements in observational studies are so important.
While 12 years of follow-up is long enough for many outcomes, a longer follow-up might be needed here to ensure the temporality of the effect: that adherence to the MIND diet preceded brain structural changes. In this study, the grey matter volume in participants with the highest and lowest adherence to the MIND diet was almost identical at baseline. While it is ideal for an experimental study to start with a similar grey matter volume before intervention, such a similarity raises questions in an observational study. This is because the level of adherence reflects participants’ dietary habits over many years prior to the baseline, and it is therefore unlikely that the effect began at the baseline. In comparison, another finding of this study shows that higher adherence to the MIND diet was associated with a better baseline profile (lower left lateral volume) and a milder decline throughout follow-up.
The stronger associations observed among those who were more physically active and weren’t overweight or obese were interpreted as suggesting that combined lifestyle strategies might help lower the risk of neurodegenerative disease. The statistical interactions the authors reported show heterogeneity among these subgroups, which may or may not reflect biological interactions (a stronger combined effect of the MIND diet and physical activity). Those subgroup differences may help in understanding the underlying mechanisms; they may also point to non-causal explanations of the observed associations.
Finally, dietary patterns are powerful tools for assessing overall diet, which seems more realistic than a single-food approach if diet can truly mitigate brain decline with ageing. However, dietary patterns are context-dependent, and translating them into dietary recommendations can be challenging, particularly across different food cultures.
Dr Jacqui Hanley, Head of Research at Alzheimer’s Research UK, said:
“Long-running studies like this help build our understanding of how lifestyle factors may influence brain health. This research suggests that people who followed the Mediterranean‑style MIND diet showed slower signs of brain ageing, although the study cannot prove a direct protective effect and did not measure impacts on memory or thinking.
“Taken together with earlier evidence, the findings add to growing indications that eating a balanced diet, staying active and taking other healthy steps may support our brain health as we age. More long‑term studies in diverse groups are still needed to untangle the role of diet, genetics and other factors.
“Tremendous progress is being made in dementia research, and we’re committed to supporting the science that will help us better understand how dementia can be prevented, treated and diagnosed earlier. While diet is not yet one of the 14 known modifiable risk factors, anyone looking for practical, evidence‑based ways to look after their brain health can use Alzheimer’s Research UK’s Think Brain Health Check‑in.”
Prof Catey Bunce, Statistical Ambassador at the Royal Statistical Society:
“The study suggests that the MIND diet may have potential to support brain health and delay aspects of structural brain ageing. However, the wording used in the paper is cautious, and it is important that the findings are interpreted with that caution in mind.
“The authors themselves highlight a number of limitations in the discussion section of the paper, which should be considered when assessing the results. One notable point is that although more than 5,000 individuals were potentially eligible for the study, the final analysis was conducted on 1,647 participants – around 32 per cent of that group.
“As with many observational studies, the results are interesting and may point to possible associations, but they should not be interpreted as definitive evidence that the diet directly prevents brain ageing.”
Prof Eef Hogervorst, Professor of Biological Psychology, Loughborough University, said:
“This Framingham Heart Study shows an association between eating a healthy diet called MIND (which is a combination of the traditional Mediterranean diet and a diet to reduce blood pressure called DASH) and later brain scan data. They found that those 60+ people who adhered to the diet had more grey matter volume as measured later, this was also shown by these people having smaller brain ventricles (so less brain volume loss). The cohort was mainly white so results cannot be generalised to other ethnicities.
“This is not the observational first study to show reduced dementia risk and better cognitive function in people who eat this type of diet with olive oil lots of fibre in the form of whole grain, (green) vegetables, beans, nuts and fruits, poultry, fish and limited red wine, salt, sweets, fried foods, red meat, cheese and butter.
“An earlier meta-analyses of 12 observational studies using this type of diet suggested an overall 15-22% reduction in dementia risk, for instance. More specifically, the authors reported a 15% reduction for the Mediterranean (Med) diet, 20% for DASH and 22% for MIND (which is DASH and Med combined).
“In the Framingham study, consumption of berries, poultry and cheese were found to be most beneficial. These association have been reported in earlier studies, including for berries in quite a number of treatment studies, even in people with cognitive impairment. For cheese our Conversation review suggested that this may pertain to limited cheese intake.
“Fried foods and whole grain carbohydrates consumption was associated with less favourable outcomes. The whole grain finding is surprising,g but while this is believed to be beneficial for gut function (which may play an important role in brain health), too much of a good thing may not be good, leading to overweight and obesity.
“The people of the Framingham Heart study who were more likely to eat the MIND type of diet were also more likely to be women, educated, not overweight and non-smokers, and less likely to have diabetes, high blood pressure and cardiovascular disease. All of these factors have been associated with loss of brain function and structure. Stronger associations of eating this diet on grey matter volume were seen in older people, those who were not overweight/obese or who were physically active.
“Diet was assessed by Food Frequency Questionnaire. This assessment could be less accurate in people who are developing cognitive decline over time and this problem was acknowledged by the authors. In other studies, longer follow-up (also associated with people getting older and some perhaps more likely to become forgetful) was not associated with better protective dietary effects on cognitive function.
“In one review, beneficial associations of these types of diets were mainly found with a follow-up of less than 6 years.It could also be that people’s diets change over time, and some of this may be due to loss of teeth and/or chewing capacity. Loss of teeth has also been associated with dementia risk. Several studies have shown loss of weight a couple of years before dementia diagnosis which could be related to a change in diet due to loss of teeth and/or forgetting to eat.
“Importantly, most treatment studies did not find that the MIND diet reduced cognitive decline, but one study did show benefit: in obese participants. Obesity has been associated with poor cognitive function, so there may have been more room for improvement than in relatively healthy middle-aged people. It may also be the case that the other studies were too short to show beneficial effects, which had been done up to 3 years.
“This data taken together suggest that engaging in multiple lifestyle behaviours including not smoking and engaging in physical activity and making sure people address health conditions such as prediabetes and hypertension, rather than only focusing on diet, is important to maintain brain health, and prevent dementia risk and cognitive decline. “
Prof Claudia Cooper, Professor of Psychological Medicine and Centre Lead, Queen Mary University of London (QMUL), said:
“This study adds to growing evidence that healthier diet may reduce our dementia risk. It is interesting that greater adherence to the MIND diet delayed structural brain changes, though we can’t necessarily say from this study that the MIND diet caused these benefits, as the authors fully acknowledge.
“They call for high-quality, long-term intervention studies. These could make an important difference to how we approach dementia prevention, though there is already strong existing evidence that healthier diets help prevent disease.”
* ‘Adherence to the MIND diet and longitudinal brain structural changes over a decade: evidence from the Framingham heart study offspring cohort’ by Hui Chen et al. will be published in Journal of Neurology Neurosurgery & Psychiatry at 22:30 hours UK time Tuesday 17 March 2026, which is when the embargo will lift.
DOI: 10.1136/jnnp-2025-336957
Declared interests:
Dr Mohammad Talaei: “I don’t have any conflict of interest.”
Dr Jacqui Hanley: “no declarations of interest”
Prof Catey Bunce: “no competing interests”
Prof Eef Hovervorst: “In the past Eef Hogervorst received funding from Sandoz Nutrition and NESTEC for caffeine related studies, from Organon for a review into HRT and cognition and from Proctor and Gamble for a review into dietary supplements and cognition. She has received funding from ARUK, ISPF, and ESRC for nutrition (tofu/tempe) research in Indonesia and the UK as well as from Loughborough University and University Indonesia. Eef also acted as dementia expert for both NICE and ESHRE guidelines on menopause and treatments to reduce dementia risk”
Prof Claudia Cooper: “No relevant conflicts; PI of a recent NIHR study APPLE-Tree that evaluated a dietary intervention at people at risk of dementia “