Eating a Mediterranean diet may help to counteract a genetic risk of strokes, research suggests.

People with two copies of a specific gene variant were less likely to suffer a stroke if they ate a diet mainly consisting of olive oil, fresh fruits and vegetables, nuts and fish.

Their stroke susceptibility became the same as that of individuals with no copies of the mutation, or just one.

The TCF7L2 gene has previously been strongly linked to type 2 diabetes but not heart and artery disease.

Scientists studied more than 7,000 Spanish men and women who ate either a Mediterranean or normal low-fat diet for almost five years.

Around 14 per cent of participants carried two copies of the gene variant associated with diabetes.

“Being on the Mediterranean diet reduced the number of strokes in people with two copies of the variant,” said study leader Prof. José Ordovas, from Tufts University in the US.

“The food they ate appeared to eliminate any increased stroke susceptibility, putting them on an even playing field with people with one or no copies of the variant.

“The results were quite different in the control group following the low-fat diet, where homozygous carriers (with two gene copies) were almost three times as likely to have a stroke compared to people with one or no copies of the gene variant.”

The research is reported online in the journal Diabetes Care.

More work is needed to uncover the mechanism behind the interaction between diet and genetic make-up, said the scientists.

The TCF7L2 gene has previously been implicated in glucose metabolism and the variant observed in the study is strongly linked to the development of type 2 diabetes.