Diet rich in veg and berries '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.

Experts found an effect 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.

The diet was linked to less brain tissue loss over time, especially grey matter, and less "ventricular enlargement" which is a marker of brain ageing.

The researchers wrote that "grey matter atrophy and ventricle volume enlargement are well-established markers of brain ageing", adding that grey matter "plays a key role in memory, learning and decision making" while ventricular enlargement reflects tissue loss.

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

"Conversely, fast fried foods, often high in unhealthy fats, trans fats and advanced glycation end-products, may contribute to inflammation and vascular damage," they wrote.

Writing in the Journal of Neurology, Neurosurgery and Psychiatry, experts analysed data from 1,647 people with an average age of 60.

They looked at their adherence to the "Mind" diet, which stands for the Mediterranean-Dash Intervention for Neurodegenerative Delay.

It is designed to support brain health and reduce the risk of Alzheimer's disease, and includes many plant-based, antioxidant-rich foods while limiting saturated fats and added sugars.

All people in the study 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 per cent 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 eight per cent 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.

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."