Twelve-year study reveals this diet could ‘slow brain ageing’

A Mediterranean diet rich in vegetables, berries, nuts and olive oil could slow down brain ageing, according to a long-term study of 1,647 adults. The Mediterranean-Dash Intervention for Neurodegenerative Delay diet (MIND) was linked to less tissue loss over time, particularly of grey matter — the brain’s information processing hub, with a key role in memory, learning, and decision-making.

People following the diet also showed less ventricular enlargement, which can reflect brain cell loss. The effects were seen across more than a decade in people whose diet contained lots of vegetables, fruit, nuts, fish, beans, olive oil and poultry plus a “moderate intake” of wine, while limiting red meat, fried foods and sweets.

International researchers led by the Zhejiang University School of Medicine in China and Harvard T H Chan School of Public Health in Massachusetts, USA, shared their findings in the Journal of Neurology, Neurosurgery and Psychiatry.

They suggested that “foods rich in antioxidants, such as berries, and high-quality protein sources like poultry, may reduce oxidative stress and mitigate neuronal damage”.

The paper added: “Conversely, fast fried foods, often high in unhealthy fats, trans fats and advanced glycation end-products, may contribute to inflammation and vascular damage.”

The team analysed data from 1,647 people with an average age of 60. They looked at their adherence to the “Mind” diet, which is designed to improve brain health, reduce cognitive decline and lower dementia risk.

The diet includes many plant-based, antioxidant-rich foods while limiting saturated fats and added sugars.

Study participants completed food frequency questionnaires and had at least two brain MRI scan assessments.

During an average monitoring period of 12 years, as people got older, they displayed loss of brain matter alongside other markers of brain loss. But those who stuck to the diet most closely had slower grey matter shrinkage and loss.

Each three-point increase in adherence to the diet was linked with slower loss, equivalent to 20% less age-related decline and two-and-a-half years of delayed brain ageing, the study found.

Similarly, each three-point increase was associated with slower expansion of total ventricular volume, equivalent to 8% less tissue loss and one year of delayed brain ageing.

The findings also suggested that benefits were greater in older people and those who were active and not overweight, suggesting combined lifestyle approaches may have a significant effect.

Commenting on the study, Dr Jacqui Hanley, head of research at Alzheimer’s Research UK, said: “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.”

Professor Catey Bunce, statistical ambassador at the Royal Statistical Society, said: “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.”