Research we're watching: More good news about the Mediterranean diet

The Mediterranean diet—with its emphasis on fruits, vegetables, fish, and plant oils—has been touted for a number of health benefits, most notably for the heart. New findings from a landmark trial are adding even more credibility to this diet's health claims. The study, known shorthand as PREDIMED, included almost 7,500 men and women, ages 55 to 80, at high risk for heart disease. Participants were randomly assigned to eat one of three diets—a Mediterranean diet supplemented with olive oil, a Mediterranean diet plus mixed nuts, or a general low-fat diet—to see how a Mediterranean style of eating affected their heart risks. In the process, the researchers also looked at a few ancillary effects of the diet on conditions like diabetes, dementia, and cancer.

Last year, PREDIMED researchers reported their finding that the Mediterranean diet prevents heart attacks, strokes, and deaths from heart disease. A study released in January in The Journal of the American Medical Association found that the diet also helps prevent peripheral artery disease, a condition in which fatty plaque builds up in the arteries that supply the head, organs, and limbs. And research published the same month in Annals of Internal Medicine found that people who ate a Mediterranean diet supplemented with olive oil were less likely to develop type 2 diabetes than those on a low-fat diet, even if they didn't cut back on calories or increase physical activity. Although these results are still preliminary, the PREDIMED study has a number of strengths—including its large numbers of participants, long-term follow-up, and head-to-head comparison with a low-fat diet—that are helping researchers better pinpoint the direct effects of the Mediterranean diet on health.