Are you nuts?

Still not convinced by the health benefits of the Mediterranean diet? Now there is another reason to follow it: it makes you happy.

People who eat a diet rich in the classic ingredients consumed in the countries bordering the Mediterranean Sea - vegetables, fruits, nuts, whole grains and fish - are less likely to develop depression, researchers have found.

Mental disorders are less common in the Mediterranean countries than in those of northern Europe and scientists believe the reason may lie with the diet.

People accustomed to the gloomy skies may imagine that the weather has a bigger impact on mood, but the researchers corrected for this effect by limiting their study to Spaniards living in Spain who were compared for the rigour with which they stuck to the classic Mediterranean diet.

Previous studies have suggested that olive oil, which contains high levels of mono-unsaturated fatty acids - and without which no Mediterranean meal is complete - may be protective against depression. Researchers from the University of Las Palmas de Gran Canaria and Clinic of the University of Navarra, Pamplona, Spain, asked 10 000 participants to record what they ate and ranked them on their adherence to nine components of the Mediterranean diet.

After following the participants for more than four years, they identified 480 new cases of depression and showed the risk of developing the illness was 30 percent lower in those who adhered most closely to the healthy diet.

"The specific mechanisms by which a better adherence to the Mediterranean dietary pattern could help to prevent the occurrence of depression are not well known," the authors write in Archives of General Psychiatry. Components of the diet may improve blood vessel function, fight inflammation, reduce risk for heart disease and repair oxygen-related cell damage, all of which may decrease the chances of developing depression.

"However, the role of the overall dietary pattern may be more important than the effect of single components. It is plausible that the synergistic combination of a sufficient provision of omega-three fatty acids together with other natural unsaturated fatty acids and antioxidants from olive oil and nuts, flavonoids and other phytochemicals from fruit and other plant foods and large amounts of natural folates and other B vitamins in the overall Mediterranean dietary pattern may exert a fair degree of protection against depression," they say.

The principal aspects of this diet include high olive oil consumption, high consumption of legumes, high consumption of unrefined cereals, high consumption of fruits, high consumption of vegetables, moderate consumption of dairy products (mostly as cheese and yoghurt), moderate to high consumption of fish, low consumption of meat and meat products, and moderate wine consumption. - The Independent

• This article was originally published on page 8 of The Sunday Tribune on October 11, 2009