Though much research has shown that eating a Mediterranean-style diet may ward off heart trouble and various other ailments, a new study from the University of Athens now shows that it may also prevent people from having a second heart-related event. The Mediterranean diet is typically high in fruits, veggies, whole grains, fish, nuts, low-fat dairy, and olive oil, and low in meat, high-fat dairy, and sweets.

When the researchers looked at each element separately, they found that only vegetables/salad and nuts were individually linked to lower risk of heart disease. People who ate these foods daily or weekly had about a 20% lower risk of having a second cardiac event over the next two years.

Christina Chrysohoou and her colleagues followed 1,000 patients who were hospitalized for either heart attack or angina (chest pain). While still at the hospital, the researchers asked the patients to answer questions about their diets over the preceding year and then ranked them according to how “Mediterranean” they were, on a scale of 1 to 55. Then, they tracked how many of the patients were readmitted to the hospital for heart trouble over the next two years.

They found that people who scored in the top third of Mediterranean diet consumption had a 31% reduced risk of heart problems within the first month of being released from the hospital, compared to people in the lowest third of Mediterranean diet consumption. Over the first year, people in the top third were almost half as likely to suffer from another cardiac event, and over two years, they were 37% less likely to suffer from a cardiovascular disease than people in the lowest third.

The researchers also write that for every point that a person’s score rose on the 55 point scale, their risk of suffering a cardiovascular event fell by 11% over the next two years.

Which components of the diet are responsible for these heart benefits? When the researchers looked at each element separately, they found that only vegetables/salad and nuts were individually linked to lower risk of heart disease. People who ate these foods daily or weekly had about a 20% lower risk of having a second cardiac event over the next two years.

The researchers caution that their results don’t demonstrate cause and effect (the study only points to a correlation between diet and heart disease), and the mechanisms, or “pathophysiologic explanations,” as the authors write, are still unknown. They do recommend that “a comprehensive strategy to decrease cardiovascular morbidity and mortality should primarily include a cardioprotective diet that contains the favorable characteristics of the Mediterranean diet.”

The findings were published in the May 19, 2010 online issue of the American Journal of Clinical Nutrition.