The Mediterranean diet should be used to fight dementia rather than ‘dubious’ drugs, a group of leading doctors has told the Government.

The doctors, have told the Health Secretary, that people should be persuaded to eat fresh fruit and vegetables, nuts, fish and olive oil to prevent Alzheimer’s and other debilitating brain diseases. Both dementia and Alzheimer’s are on the increase as people live longer.

In a letter to Jeremy Hunt, the doctors, cited numerous health studies with compelling evidence on the benefits of eating fresh fruit and vegetables.

The letter’s signatories include Dr Clare Gerada, the former chairman of the Royal College of General Practitioners, and Dr David Haslam, chairman of the National Obesity Forum.

It reads: “We hope this crisis can be seen as an opportunity towards a real policy change, namely towards a Mediterranean diet, rather than towards the dubious benefits of most drugs.”

It goes on to say the evidence ‘strongly suggests’ that improvements to lifestyle will have a ‘far greater effect’ on the rising tide of dementia than drugs.

Dr Simon Poole, the GP who organised the letter, said: “It is all about looking at what pharmaceutical companies can do, which is actually not very much.

“They talk up their medicine and then it is very often a damp squib. We want some sort of focus on prevention. Educating all generations, including our children, in the importance of a good diet in maintaining health in old age is a project which will take years, but is absolutely essential.

“We are calling upon policymakers to not only support the care and treatment of those who are already suffering from dementia, but to make significant investments in work which will see benefits beyond the period of one or two parliaments.’

He added: “People are put off because they perceive the Mediterranean diet as being expensive.

“But although fresh fish and olive oil cost more, as a whole, it need not be more expensive than the standard diet most of us have.”

In a recent review, nine out of 12 studies analysed at Exeter University credited following a Mediterranean diet with staying sharper for longer and a having lower risk of Alzheimer’s.

A 20-year study by the Medical Research Council also found that eating healthily kept the mind sharp in old age.