Fruits, vegetables and coronary heart disease.

Diet plays an important part in the maintenance of optimal cardiovascular health. This Review summarizes the evidence for a relationship between fruit and vegetable consumption and the occurrence of coronary heart disease. This evidence is based on observational cohort studies, nutrition prevention trials with fruit and vegetables, and investigations of the effects of fruit and vegetables on cardiovascular risk factors. Most of the evidence supporting a cardioprotective effect comes from observational epidemiological studies; these studies have reported either weak or nonsignificant associations. Controlled nutritional prevention trials are scarce and the existing data do not show any clear protective effects of fruit and vegetables on coronary heart disease. Under rigorously controlled experimental conditions, fruit and vegetable consumption is associated with a decrease in blood pressure, which is an important cardiovascular risk factor. However, the effects of fruit and vegetable consumption on plasma lipid levels, diabetes, and body weight have not yet been thoroughly explored. Finally, the hypothesis that nutrients in fruit and vegetables have a protective role in reducing the formation of atherosclerotic plaques and preventing complications of atherosclerosis has not been tested in prevention trials. Evidence that fruit and vegetable consumption reduces the risk of cardiovascular disease remains scarce thus far.