Mediterranean foods, complete with plenty of olive oil, could ward off mental decline.
Memory loss could be delayed by eating more fish, fruit, vegetables and nuts, it was revealed.
The diet is rich in vitamins and omega-3 polyunsaturated fats, which have been linked to cognitive function.
Omega-3, a naturally occurring fatty acid which is found in fish, seeds, meat and eggs, aids blood flow in certain areas of the brain.
“There is encouraging evidence a higher adherence to a Mediterranean diet is associated with improving cognition, slowing cognitive decline or educing the conversion to Alzheimer’s,” said Roy Hardman from the Swinburne University of Technology, Melbourne.
The diet has also been linked to a lower risk of death, and a lower risk of heart disease.
Fish oil supplements could also boost brain function, it’s been claimed.
Supplements prevented brain shrinkage, which is a hallmark of Alzheimer’s disease.
Oxford University’s David Smith said: “This is a very exciting and important result.It is the first treatment to show Alzheimer’s-related brain shrinkage can be prevented.
“It means that something so simple as keeping your omega-3 levels high and supplementing B vitamins if you are at risk could dramatically reduce a person’s risk [of Alzheimer’s].”
Omega-3 supplements have anti-inflammatory effects in the brain. The fatty acid is also found in mackerel, salmon fish oil, cod liver oil and walnuts.
Simple dietary changes could boost brain function, and potentially reduce the risk of neurocognitive disorders, including dyslexia, dyspraxia and autism spectrum disorders, scientists claimed.
Alzheimer’s disease is the most common type of dementia, affecting about 850,000 people in the UK.
The neurodegenerative condition causes memory lapses, mood changes and periods of confusion.
Latter stages of Alzheimer’s can lead to hallucinations, difficulty communicating, difficulty eating and considerable weight loss.
There is currently no cure for Alzheimer’s disease. But, some medication can reduce symptoms, and delay to progress of the condition.