The diet that’s proven to slash your risk of dementia: experts reveal the exact healthy eating plan that can slow brain ageing

A ‘brain healthy’ diet could slow the physical deterioration linked to Alzheimer’s and Parkinson’s disease, scientists say.

In a major long-term study, those who stuck closest to it showed slower loss of brain cells and less overall shrinkage on scans – changes strongly linked to memory loss and dementia.

The eating plan – dubbed the MIND diet, short for Mediterranean–DASH Intervention for Neurodegenerative Delay – emphasises foods such as leafy green vegetables, berries, nuts, olive oil and fish.

It has previously been linked to a lower risk of dementia, but researchers now say they have proof that it helps slow the damage that leads to these diseases.

Writing in the Journal of Neurology, Neurosurgery & Psychiatry, the researchers said encouraging people to follow the diet could be a simple way to help tackle rising rates of dementia as populations age.

To investigate its effects, researchers tracked 1,647 middle-aged and older adults from the Framingham Heart Study Offspring cohort for around 12 years.

Participants completed detailed dietary questionnaires covering roughly 140 food items and underwent at least two MRI scans over the study period.

Researchers then calculated a MIND diet score ranging from 0 to 15, based on how closely each participant’s eating habits matched recommendations across nine encouraged food groups, five restricted food groups and moderate wine intake. 

On average, participants scored 6.8 out of 15.

Those with the highest scores were more likely to be women, college educated and non-smokers. They also had lower rates of type 2 diabetes, high blood pressure and heart disease – all of which are known to increase the risk of dementia.

Lifestyle factors including smoking, physical activity and body mass index were also taken into account.

As expected, all participants showed some degree of age-related brain decline over the course of the study.

But those who adhered more closely to the MIND diet experienced a slower decline in grey matter and less enlargement of the brain’s ventricles – fluid-filled spaces that expand as brain tissue is lost.

The most notable differences were seen in the hippocampus, a region crucial for learning and memory.

Grey matter is rich in nerve cells and plays a central role in memory, learning and decision-making, while ventricular enlargement is a key marker of brain atrophy. 

Researchers found that a three-point increase in MIND diet score was associated with the equivalent of a two-and-a-half-year reduction in brain ageing.

Those who followed the diet more strictly also showed slower ventricular expansion, equivalent to roughly a one-year delay in brain ageing.

The benefits appeared strongest in older adults, people who were physically active and those who were not overweight – suggesting a combined lifestyle approach may offer the greatest protection.

The researchers said foods promoted by the diet may help protect the brain by reducing oxidative stress and inflammation.

They wrote: ‘MIND-recommended foods rich in antioxidants, such as berries, and high-quality protein sources like poultry may reduce oxidative stress and mitigate neuronal damage.

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

However, the study also produced some unexpected findings.

Higher wholegrain intake was linked to less favourable changes in several brain markers, including faster decline in grey matter, while higher cheese intake was associated with slower decline.

The researchers said further long-term studies are needed to better understand how specific foods and dietary patterns influence brain ageing.

Professor Eef Hogervorst, an expert in biological psychology at Loughborough University, said the findings should be interpreted alongside other lifestyle factors.

She said: ‘This 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.’

Michelle Dyson, chief executive of Alzheimer’s Society, also welcomed the findings.

She said: ‘Further research into prevention is vital.

‘Continuing to grow our understanding of risk, and encouraging people to quit smoking, keep physically active, eat a healthy balanced diet, control blood pressure and drink less alcohol can all help reduce the risk of dementia.’

Around 900,000 people in the UK are currently living with dementia, a figure expected to rise to more than 1.6 million by 2040. It is the leading cause of death, accounting for more than 74,000 deaths each year.