Two diets that can stave off dementia – and the best food to eat

How healthy your lifestyle is can make a significant difference to your risk of being diagnosed with dementia, a study has revealed.

Research has shown that your diet, how often you exercise and the type of exercise you do can help to lower the risk of dementia to a larger extent than previously thought. Part of the justification lies in the idea that eating foods that protect your heart and keeping it well exercised is key to also protecting your brain.

A healthy cardiovascular system keeps blood vessels open, allowing blood flow to the brain and reducing the risk of high blood pressure, stroke and dementia. Jeffrey Burns, co-director of the University of Kansas Alzheimer’s Disease Research Center in Fairway, said: “There’s a lot of data that suggests exercise and diet are good for the brain and can prevent or help slow down”. So foods such as whole grains, vegetables, fruit, and small amounts of saturated fat and sodium, you could be in the green.

But there are two dietary approaches in particular – the Mediterranean diet and the MIND diet – that research suggests might particularly help delay cognitive decline. The diets are largely plant-based, along with olive oil, fish and poultry, and the main difference between the two is that the MIND diet emphasises specific fruit and vegetables, the Wall Street Journal report.

The studies suggest most of those who closely follow the diets have a reduced risk of dementia – over a nine year study of over 60,000 men and women, the Mediterranean diet had a 23 per cent lower risk of dementia. The MIND diet found that older adults who stuck rigidly with the diet had a 53 per cent lower chance of developing Alzheimer’s, and those who followed it moderately had a 35 per cent risk reduction.

Brain-boosting foods are “associated more with overall brain health”. Focussing on one food doesn’t “magically improve cognitive functioning”, assistant professor at the Rush Alzheimer’s Disease Center Puja Agarwal said, but a combination will give some extra protection. See below for the best foods to stick to to improve cognitive function:

Healthy fats such as avocados, olives, nuts, seeds and olive oil protect you from heart disease and stroke – which are risk factors for Alzheimer’s. The mono- and polyunsaturated fats and Omega-3 fatty acids – found in seafood and walnuts – may slow an ageing brain.

Berries contain flavonoids – powerful antioxidants. They are believed to protect brain cells from damaging oxidative stress and help to boost memory.

Leafy greens “are powerhouse, nutrient-dense foods” with “anti-inflammatory and antioxidant properties”, Agarwal said. A recent study found those who eat seven or more servings of leafy greens per week had amyloid plaque levels similar to people 19 years younger.

Beans are rich in fibre, such as lentils, chickpeas, and kidney beans. A 2022 study in the American Journal of Medicine suggested that increased fibre in older people boosts scores on a brain function test which measured information processing, attention and memory.

Fibre helps the brain by supporting a healthy microbiome – the good bacteria living in your gut necessary for healthy digestion. Their activity creates short-chain fatty acids which communicate with the brain, and some data shows those with Alzheimer’s have a different microbiome makeup to those without it.

Eggs are rich in choline – the nutrient important for brain function. A 2019 study of 500 men found that every 50 milligram intake of a specific type of choline per day is linked with a 10 per cent dementia risk decrease.