Primary Prevention of Cardiovascular Disease with a Mediterranean Diet (PREDIMED)

Researchers randomly assigned 7,447 older adults in Spain to follow one of three diets. All had a higher-than-usual risk of heart disease but had not yet had it. Two groups followed a Mediterranean diet with either extra-virgin olive oil or nuts, while the third received advice to eat less fat. After about five years, the Mediterranean-diet groups had roughly 28% to 30% fewer major cardiovascular events, meaning heart attacks, strokes, or deaths from heart disease.

What this means for you: For people at higher risk of heart disease, eating more Mediterranean-style foods, especially replacing less healthy foods, is a reasonable choice. The study does not prove that olive oil or nuts alone extend life, and its participants were older Spanish adults, so the results may not apply equally to everyone.