Eating a Mediterranean-style diet for three months can reduce the risk of heart disease by 15 percent, a new study shows.

The heart-healthy effects of the Mediterranean diet - rich in whole grains, fruits, vegetables, nuts and fish and olive oil and light on red meat - are well documented, Dr. Denis Lairon of the Faculty of Medicine Timone in Marseille, France and colleagues note in the American Journal of Clinical Nutrition. But just one other study has looked at what happens when healthy people are actually put on a Mediterranean-style diet.

To investigate, the researchers assigned 212 men and women at moderate risk for heart disease to eat a Mediterranean diet or a standard low-fat diet for three months.

Participants on the Mediterranean diet were instructed to eat fish four times a week and red meat only once a week. Men were allowed two glasses of red wine daily, while women were limited to one.

Recommendations for people on the low-fat diet were to eat poultry rather than beef, pork and other mammal meats; eat fish two or three times a week; stay away from animal products rich in saturated fat; and eat fruit and vegetables, low-fat dairy products, and vegetable oils.

While study participants did not follow all diet recommendations, the researchers found, eating habits did change in both groups. Study participants took in fewer calories and consumed more proteins and carbohydrates and less total fat and saturated fat. Both groups showed a small but significant drop in body mass index.

Among people on the Mediterranean diet, total cholesterol dropped by 7.5 percent, and it fell by 4.5 percent in the low-fat diet group. Based on this reduction, the researchers write, overall cardiovascular risk fell 15 percent with the Mediterranean diet and 9 percent with the low fat diet.

“Both diets significantly reduced cardiovascular disease risk factors to an overall comparable extent,” the researchers conclude.

SOURCE; American Journal of Clinical Nutrition, November 1, 2005.