A Mediterranean diet has long been thought to improve general health but this particular study of 74,607 men and women aged over 60 shows that by closely following the diet life can be extended by up to one year.

Information on diet, lifestyle, medical history, smoking and physical activity was collected by the scientists and the men and women were each given a score based on adherence to a Mediterranean diet, with higher scores given to those who ate the most foods linked to such a diet.

The researchers found that a higher dietary score was linked to a lower overall death rate and that a two-point increase in the score was linked to an 8% reduction in mortality, a three-point increase was associated with an 11% drop in mortality and a four-point increase was associated with a 14% drop.

A healthy man of 60 who closely followed a Mediterranean diet could expect to live around one year longer than a man of the same age who did not eat such a diet.

The link was strongest in Greece and Spain and that was probably because people in these countries followed a genuine Mediterranean diet.

According to Rebecca Foster, a nutrition scientist at the British Nutrition Foundation, diets in the UK were nothing like as healthy as those followed by many European counterparts. She says that although dietary surveys show that Brits are eating fewer calories, less total fat and are reducing salt intake, they are still not meeting the UK dietary guidelines, which are in line with the characteristics of the Mediterranean diet. Mediterranean countries such as Spain and Greece eat a lot more fruit and vegetables and less saturated fat. But Foster says the study findings could in part be down to genetic factors, rather than simply diet alone.

Dietary studies are often hard to carry out as it is difficult to define which constituent of the diet provides the most benefit, says Belinda Linden, of the British Heart Foundation, but that should not stop them trying, as large and in-depth dietary studies such as these contribute to a greater understanding of the way different diets affect health, and adds detailed evidence to previous findings confirming that this type of diet, can be linked with prolonged life.

Linden says however that diet is only one part of the lifestyle change needed to reduce coronary heart disease and we must also aim to increase our activity levels, control our weight and stop smoking.

The study is published in the British Medical Journal.