A Mediterranean diet, rich in olive oil, nuts, beans, fish, fruits and vegetables, was found to prevent about 30 percent of heart attacks, strokes and deaths from heart disease in people at high risk, according to a new study. These results were so pronounced that the study ended early, after five years, because it was deemed unethical to continue.
The study authors, based in Spain, randomized almost 7500 individuals who were overweight, smokers, or had diabetes or other risk factors for heart disease, into three groups: one group was instructed to follow a low-fat diet; one group was instructed to follow a Mediterranean diet with an emphasis on using at least four tablespoons of olive oil a day; the last group was instructed to follow a Mediterranean diet with an emphasis on eating an ounce of nuts (some combination of walnuts, almonds or hazelnuts) per day. Both groups following the Mediterranean diet were also instructed to stay away from processed cookies, cakes and pastries and to limit consumption of dairy and processed meats.
Compliance with the Mediterranean diets was measured using specific markers; a marker in urine for those consuming olive oil and a blood marker for those consuming nuts. It was found that participants mainly adhered to the Mediterranean diets but those in the control group did not lower their fat intake very much.
This study is the first major clinical trial measuring the effects of the Mediterranean diet on heart risk. Previous evidence supporting the Mediterranean diet was based on studies looking at the lower rate of heart disease in people from Mediterranean countries, a finding that may have been due to other factors.
Rachel Johnson, a professor of nutrition at the University of Vermont and a spokeswoman for the American Heart Association, says that this study is really impressive. And the really important thing the coolest thing is that they used very meaningful endpoints. They did not look at risk factors like cholesterol or hypertension or weight. They looked at heart attacks and strokes and death.
ACSH s Dr. Ruth Kava noted These results lend weight to advice that people at risk can benefit from adhering to a Mediterranean-style diet. Whether the benefits can be generalized to the population at large remains to be demonstrated.