The Mediterranean diet has long been touted as healthy. Now a study released Monday showed eating a diet rich in olive oil, nuts, vegetables, fruits and fish confirms that.

The study, which was published in the New England Journal of Medicine, showed the diet can reduce the risk of stroke and other cardiovascular diseases by 30 percent.

Such a diet may seem like common sense, but researchers say the findings are significant because of the size of the study and its scientific rigor. It followed more than 7,400 people at risk of heart disease for nearly five years and measured the effects of the Mediterranean diet against a group that was assigned a low-fat diet.

"This study backs up what we thought we knew with science, and the results were pretty dramatic," said Dr. Rita Redberg, a UCSF cardiologist specializing in heart disease in women, who was not involved in the study. "If this were a pill, people would be clamoring for it."

3 groups studied

The study, which was conducted in Spain, involved people between the ages of 55 and 80 who did not have heart disease but were at risk of developing cardiovascular problems because of various factors, such as being overweight, smoking, having a family history of the disease or high blood pressure and high cholesterol.

Participants were assigned to one of three groups. People in two of the groups were required to follow a Mediterranean diet, in other words meals rich in vegetables, fruit, fish and legumes. Those involved in one of the Mediterranean diet groups were instructed to add at least four tablespoons a day of extra-virgin olive oil to their daily diet. Those in the other group supplemented their meals with a combined ounce of walnuts, almonds and hazelnuts each day.

Study ended early

The "control" group, or the group that was being compared against participants in the Mediterranean diet, were encouraged to lower their fat intake by eating lean meats and low-fat dairy products. Midway through the study the study's authors said they intervened to offer more specific guidance of what the group should eat and how to prepare their foods.

The results were so clear that the study was ended early. The two groups assigned to the Mediterranean diet had fairly similar results, with 3.4 percent of the group that ate extra nuts suffering major cardiovascular problems compared to 3.8 percent in the olive-oil group.
