A 15-minute online test has been developed to reveal early signs of Alzheimer’s disease.
The free quiz was developed by mental health experts and is aimed at 50 to 70-year-olds who are worried about memory decline.
The interactive test provides an immediate result and advice about lifestyle and diet changes.
Those at risk are given a letter for their GP.
Professor David Smith, of Oxford University, said: “Alzheimer’s is a preventable disease, not an inevitable part of the ageing process.
“Rather than leaving it until too late, the trick is to identify any decline in memory function as early as possible and take the necessary prevention steps.”
Research shows poor diet and a bad lifestyle are linked to memory decline and the risk of Alzheimer’s.
Three in 10 over-70s have impaired memory, and potentially 75% of these will develop Alzheimer’s or some form of dementia within five years.
“Only about one in a hundred cases of Alzheimer’s is caused by genes,” said Prof Smith.
“As long as decline in memory function is identified early, research has shown that a combination of specific B vitamins, dietary and lifestyle changes, can greatly reduce the rate at which your brain shrinks, and your memory worsens.”
Over-50s with a raised blood level of homocysteine - a toxic amino acid - experience accelerated brain shrinkage, research has shown, and have poorer memories than people with less homocysteine.
But a diet rich in B vitamins greatly reduces the shrinkage.
GP Dr Andrew McCaddon welcomed the online Cognitive Function Test.
“People often struggle for three years or more with forgetfulness before they come to see me,” he said.
“As there is now good evidence for lowering elevated homocysteine levels with high dose B vitamins, I prescribe these to my patients and I have found significant clinical improvement from this approach. Early screening is the way forward.”
Eating more fish, learning new things and keeping physically and socially active also reduce the risk.
Visit www.foodforthebrain.org to take the test.