A group of doctors in the UK are advocating a Mediterranean diet over the use of "dubious" drugs in preventing dementia.
In a letter to the health secretary, UK secretary of state for health, Jeremy Hunt wrote that persuading people to follow this diet was "possibly the best strategy currently available."
The team will present their findings at an international health summit in London. In his letter, Hunt goes on to call dementia a health "time bomb", predicting the number of people living with the condition to triple worldwide to 135 million by 2050.
As well as protecting against dementia, a Mediterranean diet is also beneficial in preventing coronary heart disease, hypertension and diabetes. In nine out of 12 studies by the University of Exeter's Medical School, this type of diet improved cognitive function, and reduce the risk of Alzheimer's disease, while also lowering the rate of decline in sufferers.
"Mediterranean food is both delicious and nutritious, and our systematic review shows it may help to protect the ageing brain by reducing the risk of dementia," said lead researcher Iliana Lourida from the University of Exeter.
"While the link between adherence to a Mediterranean diet and dementia risk is not new, ours is the first study to systematically analyse all existing evidence."