Intake of vegetables rich in carotenoids and risk of coronary heart disease in men: The Physicians' Health Study

Background Previous studies of diet and corollary heart disease (CHD) have focused on intake of nutrients rather than whole foods. Because of the find ings that dietary fibre, folate and antioxidants may be protective for CHD, increased intake of vegetables has been recommended. However, due to the c hemical and physical complexity of vegetables, the effects of individual nu trients may differ if eaten as whole foods. Moreover, little is known about the direct association between vegetable intake and risk of CHD. Methods We prospectively evaluated the relation between vegetable intake an d CHD risk in the Physicians' Health Study, a randomized trial of aspirin a nd beta-carotene among 22 071 US male physicians aged 40-84 years in 1982. In this analysis, we included 15 220 men without heart disease, stroke or c ancer at baseline who provided information on their vegetable intake at bas eline, and in the 2nd, 4th and 6th years of follow-up using a simple semiqu antitative food frequency questionnaire including eight vegetables. We conf irmed 1148 incident cases of CHD (387 incident cases of myocardial infarcti on and 761 incident cases of coronary artery bypass grafting or percutaneou s transluminadl coronary angioplasty) during 12 pears of follow-up. Results After adjusting for age, randomized treatment, body mass index (BMI ), smoking, alcohol intake, physical activity, history of diabetes, history of hypertension, history of high cholesterol, and use of multivitamins, me n who consumed at least 2.5 servings/day of vegetables had a relative risk (RR) of 0.77 (95% CI : 0.60-0.98) for CHI), compared with men in the lowest category (<1 serving/day). Adjusting for the same covariates in an analysi s of the overall trend that considered intake of vegetables as a continuous variable, we found a RR of 0.83 (95% CI : 0.71-0.98) for risk of CHD for e ach additional serving/day of vegetables. The inverse relation between vege table intake and CHD risk was more evident among men with a BMI <greater th an or equal to>25 (RR = 0.71, 95% CI : 0.51-0.99) or current smokers (RR = 0.40, 95% CI : 0.18-0.86) comparing highest to the lowest categories of int ake. Conclusions Our results suggest an inverse association between vegetable in take and risk of CHD. These prospective data support current dietary guidel ines to increase vegetable intake for the prevention of CHD.