Mediterranean diet reduces cognitive decline

Ralph Martins

Professor Ralph martins 

Professor Ralph Martins, Foundation Chair Ageing and Alzheimer’s Disease at Edith Cowan University, said the new study was the first to demonstrate the protective nature of adherence to this dietary pattern for Alzheimer’s disease in Australia.

The study, undertaken by recently completed PhD candidate Samantha Gardener, built on evidence of the benefits of a Mediterranean diet — one high in legumes, vegetables, fruit, cereals and fish and low in fatty saturates, meat and poultry.

“It has been shown in other populations in the US and Europe that people who adhere strongly to the Mediterranean diet show a lower risk of Alzheimer’s disease but it had not been shown before in Australia,” Professor Martins said. “More than that, we were the first to show that this diet is linked to what is happening in the brain, particularly the beta amyloid, which is the toxic protein that kills brain cells, particularly those to do with memory and learning.”

The researchers looked at more than 500 participants aged 60 and older, and divided them into those who practised an ‘Australian’ Mediterranean diet, a prudent diet and what they termed a typical Western diet. Each group was then graded based on how closely they adhered to the range of foods in each dietary pattern.

The researchers found those who adhered closely to the Mediterranean diet showed reduced decline in executive function over three years, while those in the Western diet had an increased rate of cognitive decline.

Professor Martins said that while the study pointed strongly to the benefits of the Mediterranean diet, the more closely a person followed the diet, the greater its protective effects.

“It has to be consistent,” he said.

“It is very hard to have a Mediterranean diet every day but if you are 80 per cent or 90 per cent consistent that’s a very good outcome. On the other hand, though, if you smoke the protective benefit is lost.”

Professor Martins said the research, published in the journal Molecular Psychiatry, could now be expanded by studying a larger group of Australians.

“The next approach is then to look at intervention programs and examine specific dietary components,” he said.

“Studying key nutrients that are within these diets means will enable us to determine if they can be used as a means of preventing Alzheimer’s in clinical trials.”

In the longer-term, he said, the diet could be paired with exercise and brain training to develop an evidence-based approach to reducing Alzheimer’s risk.

“There is no single magic bullet,” Professor Martins said.

“Diet is very important but we know you have to do it together with other lifestyle approaches that are protective to get a full benefit.” 

 This article originally appeared in the Faculty of Health Engineering and Science’s online magazine COHESION. Visit the COHESION website for more articles.