How fruits and vegetables may protect the heart.

How fruits and vegetables may protect the heart.

If you could cut your risk for heart disease by almost 25 percent simply by adding a banana at breakfast, an apple at lunch and a salad at dinner, would you do it? Of course you would. Cardiovascular disease, after all, claims more than 800,000 American lives each year. Thus, last fall, when French researchers reported in the October 2006 issue of the Journal of Nutrition that each vegetable or fruit serving you add to your day may cut your risk of heart disease by as much as 7 percent, we took notice.

Research has long linked eating plenty of produce with a reduced risk for heart disease. While most studies suggest only associations between high intakes of vegetables and fruits and lowered heart-disease risk (not proof of specific cause-and-effect relationships), scientists have many theories for how these foods may protect the heart. Potassium, a mineral abundant in vegetables and fruits, helps the kidneys excrete excess sodium, thereby contributing to healthy blood pressure. Dietary fiber has been linked with both improved glucose control (and thus reduced risk for diabetes, a condition that elevates risk for cardiovascular disease) and more favorable cholesterol levels. But even beyond those benefits, there seems to be something uniquely cardio-protective about fruit and vegetables. "Possibly, there are synergistic effects between vitamins and/or minerals and phytochemicals (such as lycopene) that protect the blood vessels leading to the heart from damage by free radicals," says Tara Gidus, R.D., a spokesperson for the American Dietetic Association.

This recent report underscores the idea that loading up on vegetables and fruits can add up to big health gains. Still, its authors point out that benefits may not be quite as big as their calculations suggest, acknowledging that their analysis estimated the magnitude of the cardiovascular benefits from the collective data of just nine studies that had found an association between high intakes of fruits and vegetables and a reduced risk of heart disease. The studies did include nearly a quarter-million subjects, total. Each of these studies assessed subjects' fruit and vegetable intakes differently, which may have skewed the results. The researchers also emphasized that the studies were observational in nature (i.e., they asked subjects about their eating habits, then looked for correlations with heart disease) and couldn't entirely rule out the impact of other lifestyle factors, such as exercise, on disease risk.

Bottom line: Even if recent research overestimates the cardiovascular benefits achieved by boosting intake of produce, "you can't go wrong by eating more fruits and vegetables," says Gidus. "Compared to other foods, they're low in calories and rich in fiber, vitamins, minerals and disease-fighting phytonutrients."