You’ve heard it a thousand times: The key to a healthy heart and brain is a healthy diet. For a growing number of people, a Mediterranean-style diet has been the stand-in for “healthy diet.” A landmark clinical trial done in Spain, known by the acronym PREDIMED, has been putting the Mediterranean eating plan on a more solid scientific foundation.
Last year, PREDIMED researchers reported that Mediterranean-style eating—rich in fruits, vegetables, and healthy plant oils—prevents heart attacks, strokes, and death from heart disease. This week in The Journal of the American Medical Association, they report that a healthy Mediterranean-style diet can also help prevent peripheral artery disease (PAD), a form of “hardening of the arteries.” PAD happens when fatty deposits obstruct the arteries that supply blood to parts of the body beyond the heart and brain, like the legs, arms, and abdomen.
“To our knowledge, this is the first randomized primary prevention trial to suggest an association between a dietary intervention and [reduced risk of] PAD,” the study authors wrote.
It’s an important finding. As many as 12 million Americans, most of them older, have PAD. It can cause leg pain when walking that goes away with rest (called intermittent claudication); a weakening of the aorta, the main pipeline that delivers blood to the body; pain after eating; erectile dysfunction; and other problems.
Though the findings were solid, keep in mind that they are preliminary. For one thing, PREDIMED was not designed to detect an effect of diet on the risk of developing PAD—although it’s not hard to imagine it being able to do so, given the diet’s effect on heart and artery health. To be scrupulously scientific, such incidental findings need to be confirmed with a study specifically targeted at PAD.
But taken as a whole, the PREDIMED trial has gone a long way to place healthy eating on par with medication as a way to prevent heart disease and stroke. Many previous studies observed that people who ate the Mediterranean way seemed to be healthier than others, but only a randomized clinical trial can pinpoint cause and effect.
“PREDIMED is a randomized trial and, as such, it provides higher quality evidence in comparison to evidence from observational studies on the health benefits of the Mediterranean diet,” says Dr. Dimitrios Trichopoulos, an epidemiologist with the Harvard School of Public Health who has conducted some of those studies.
In Spanish, PREDIMED stands for Prevención con Dieta Mediterránea, or “prevention with Mediterranean diet.” The Mediterranean diet is not a specific eating prescription, but rather a general style of eating that emphasizes certain healthy foods and minimizes other not-so-healthy ones. The basic mix is a variety of fruits, vegetables, nuts, and seeds, along with moderate consumption of fish, poultry, dairy, eggs, and olive oil, and minimal red and processed meat. Some cultures that favor Mediterranean-style diets may include a glass of red wine with their meals, but it isn’t required.
In PREDIMED, nearly 7,500 men and women were randomly assigned to adopt one of three diets: a reduced-fat diet or a Mediterranean diet supplemented with generous amounts of either nuts or extra virgin olive oil. Participants were 55 to 80 years old and at high risk of cardiovascular disease, but were still healthy at the time they entered the study.
As reported earlier in The New England Journal of Medicine, the trial found that a Mediterranean diet reduced the risk of cardiovascular problems by around 30%. In a more recent report from PREDIMED, the olive oil-supplemented version of the Mediterranean diet reduced the risk of developing diabetes by 40%.
How to go Mediterranean
It’s not hard to get started on a Mediterranean style of eating. Here are some general cooking and meal-planning tips from the Harvard Health Letter to help you make the transition:
- Sauté food in olive oil, not butter. Make your own salad dressings with extra-virgin olive oil, which is pressed mechanically from ripe olives and processed without high heat or chemical solvents. This protects healthy substances in the oil.
- Eat more vegetables by having them as a snack, or adding them to other recipes. Include a portion of fruit with breakfast and desserts.
- Choose whole grains instead of refined breads and pastas.
- Incorporate kidney beans, lentils, and other legumes in salads and side dishes.
- Substitute fish for red meat at least twice per week. If you don’t like fish, use beans or poultry to get your protein.
- Limit high-fat dairy by switching to skim or 1% milk from 2% or whole milk.
- Add a modest portion of nuts to cooked grain and side dishes, and sprinkle nuts and seeds on salads.