A new study has debunked the benefits of Mediterranean diet which claims to prevent dementia.
There is no evidence that a Mediterranean diet which involve eating plenty of fruit, vegetables and oily fish boosts memory or concentration in old age, say French scientists.
It has been shown that the diet can prevent heart disease and cancer as well as increase life expectancy.
A number of recent studies have also suggested that Mediterranean diet may be beneficial for the brain and could stave off Alzheimer's.
Some scientists believe that because the diet is low in saturated fat, it prevents the blood vessels that supply the brain becoming blocked.
But in a paper published in the American Journal of Clinical Nutrition, academics from Paris Sorbonne University have revealed there is no evidence for such a link, the Daily Mail reported.
The researchers tracked the diets of 3,000 middle-aged adults for more than a decade and divided them into three groups depending on how 'Mediterranean' their diet was.
When the adults were 65 and over, they took six tests, which checked their concentration and memory.
The results found no difference between the scores of the three groups.
Lead researcher Emmanuelle Kesse-Guyot said that midlife adherence to a MedDiet was not associated with global cognitive performance [brain power assessed 13 years later].
The researchers also noted that recent work by other scientists had also failed to find any link.
Last year, the Foundation for Public Health in Paris found women over 65 who followed a Mediterranean diet did not perform any better in memory tests.