Fruits and vegetables and heart disease. (Scientific update: a review of recent scientific papers related to vegetarianism).

There have been two recent reports on fruits and vegetables and heart disease. The first was a large study of more than 80,000 women and 42,000 men that examined fruit and vegetable consumption and heart disease. Dietary intakes were assessed at various points throughout the study. Women were followed for 14 years and men for eight years to see which factors were associated with heart attacks or deaths from heart disease.

The results of this study will be very appealing to vegetarians and others whose diets include generous amounts of fruits and vegetables. Those who had the highest intakes of fruits and vegetables had a markedly lower risk for heart disease compared to those eating the smallest amount of fruits and vegetables. An intake of more than four servings per day seemed to reduce the risk of heart disease, and eight or more servings per day led to an even greater decrease. If the number of fruits and vegetables eaten daily increased by only one serving per day, there was a four percent lower risk of heart disease. A two-serving increase reduced risk eight percent and so on. The fruits and vegetables that appeared to have the greatest effect were green leafy vegetables, vegetables in the cabbage family (broccoli, cabbage, etc.), and vitamin C-rich fruits and vegetables (citrus fruits, strawberries, broccoli). While the results seen are not quite as dramatic as those seen when certain drugs are used (statins), there are so many other benefits of consumption of fruits and vegetables that eating at least eight servings per day of fruits and vegetables sounds like a very prudent move. So, add some berries to your breakfast bowl of cereal, put lots of sliced tomatoes on your sandwich at lunch (or try a veggie sandwich), add finely chopped kale to a pot of soup, and crunch some raw or lightly steamed broccoli for a snack.

The second study was an intervention study in which one group was placed on a diet with more fruits, vegetables, and lowfat dairy products (lower in fat and saturated fat); another group was placed on a diet with more fruits and vegetables; and a third group remained on their usual diets. They followed these diets for eight weeks. The group on the diet with fruits, vegetables, and dairy products saw a reduction in their total, HDL, and LDL cholesterol levels as well as a reduction in blood pressure. Triglyceride levels did not increase. This is significant because usually lowfat, high-carbohydrate diets lead to an unfavorable increase in triglyceride levels. Perhaps this is not as likely to occur when a lower-fat diet is based on plants and whole grains.

Few changes were seen in the groups eating more fruits and vegetables, and the group eating their usual diets, probably because their diets continued to have higher levels of fat and saturated fat. It would have been interesting to see if a diet that was low in fat and saturated fat and high in fruits and vegetables (but not in dairy products) would have had the same effect. The study authors recommend that typical Americans eat twice the average daily servings of fruit, vegetables, and dairy products; one-third the usual amount of beef, pork, and ham; one-half the usual amount of fats and oils; and one-quarter the usual amount of snacks and sweets.

It certainly appears, based on these studies, that eating more fruits and vegetables can have significant health effects.

Joshipura KJ, Hu FB, Manson JE, et al. 2001. The effect of fruit and vegetable intake on risk for coronary heart disease. Ann Intern Med 134:1106-1114.

Obarzanek E, Sacks FM, Vollmer WM, et al. 2001. Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial. Am J Clin Nutr 74:80-89.

Blackburn GL. 2001. The public health implications of the Dietary Approaches to Stop Hypertension Trial. Am J Clin Nutr 74:1-2.