Mediterranean diet rich in seafood and vegetables may slash dementia chances by nearly a quarter

A diet rich in seafood, whole grains, nuts and vegetables could slash the chances of dementia by almost a quarter, a study suggests.

Those who ate a Mediterranean diet were significantly less likely to develop the brain disease, research involving more than 60,000 Britons concluded.

Experts say the findings are further evidence diet is an important modifiable risk factor in developing the disease, alongside other lifestyle factors such as smoking and lack of exercise.

It is thought nutrition could be a key driver of brain health, with previous research having linked deficiencies to dementia and cognitive decline in later life.

Researchers studied data from more than 60,000 individuals aged 60 and above from the UK Biobank – an online database of medical and lifestyle records from more than half a million people.

Participants were asked to provide details of their diet — involving 206 foods and 32 types of drinks — during the previous 24 hour period, every three to four months for around 18 months.

They were then scored on their adherence to the Mediterranean diet, based on the findings.

Over the course of nearly a decade, there were 882 cases of dementia, according to the results published in the journal BMC Medicine.

Participants who scored highest with the Mediterranean diet had a 23 per cent lower risk of developing dementia in comparison with those with the lowest adherence score, equivalent to an absolute risk reduction of 0.55 per cent.

WHAT SHOULD A BALANCED DIET LOOK LIKE?

Meals should be based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain, according to the NHS

• Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count

• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain

• 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on

• Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options

• Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)

• Choose unsaturated oils and spreads and consuming in small amounts

• Drink 6-8 cups/glasses of water a day

• Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day

Source: NHS Eatwell Guide 

They were more likely to be female, have a BMI within the healthy range, have a higher educational level, and be more physically active than those with lower adherence, researchers found.

The findings suggest the Mediterranean diet has a ‘protective effect’ against dementia, regardless of a person’s genetic risk, although more research is needed to explore this finding they say.

Dr Oliver Shannon, lecturer in Human Nutrition and Ageing at Newcastle University who led the study, said: ‘Dementia impacts the lives of millions of individuals throughout the world, and there are currently limited options for treating this condition.

‘Finding ways to reduce our risk of developing dementia is, therefore, a major priority for researchers and clinicians.

‘Our study suggests that eating a more Mediterranean-like diet could be one strategy to help individuals lower their risk of dementia.’

Experts have long suspected that a person’s nutritional intake could affect their dementia risk, especially when it comes to vascular dementia — caused by reduced blood flow to the brain.

Folate – found in dark green leafy vegetables, beans, nuts and seeds — reduces circulating levels of the blood amino acid homocysteine which has been linked to Alzheimer’s.

Similarly, it is thought vitamin E in plant-based oils, nuts, seeds, fruits, and vegetables, may be protective through its strong antioxidant effect.

Conversely, monosaturated and saturated fatty acids in meat and dairy has been linked to an increased dementia risk because they could encourage blood clot formation.

Dr Susan Mitchell at Alzheimer’s Research UK, said: ‘There is a wealth of evidence that eating a healthy, balanced diet can help reduce the risk of cognitive decline. But evidence for specific diets is much less clear cut.

‘This new, large study adds to this overall picture, but it only drew on data from people with White, British or Irish ancestry. 

‘More research is needed to build on its intriguing findings and uncover whether these reported benefits also translate to minority communities, where historically dementia has often been misunderstood and highly stigmatised, and where awareness of how people can reduce their risk is low.

‘While there are no sure-fire ways to prevent dementia yet, a diet rich in fruit and vegetables, along with plenty of exercise and not smoking, all contribute to good heart health, which in turn helps to protect our brain from diseases that lead to dementia.’