DO NUTRITIONAL SUPPLEMENTS LOWER THE RISK OF STROKE OR HYPERTENSION

Between 1986 and 1991, 29,584 persons rook Dart in a randomized nutrit ional intervention trial in Linxian, China, an area whose residents ha d chronically low intakes of several nutrients and high rates of esoph ageal and gastric cardia cancer as well as stroke. Using a one-half re plicate of a 2(4) factorial design, we randomized individuals to one o f eight groups which received combinations of four supplements: retino l and zinc (factor A); riboflavin and niacin (factor B); vitamin C and molybdenum (factor C); and beta-carotene, alpha-tocopherol (vitamin E ), and selenium (factor D). Deaths that occurred during 5 years of sup plementation were ascertained and classified according to cause. At th e end of the supplementation period, we measured blood pressure readin gs and determined the prevalence of hypertension. Participants who rec eived factor D had reductions in total mortality (9%) and total cancer mortality (13%). These individuals also had the largest reduction in stroke mortality (relative risk = 0.91; 95% confidence interval = 0.76 -1.07). End-of-trial hypertension, however, was not less prevalent amo ng those receiving factor D. Our findings contrast with the larger red uctions in stroke death and hypertension found in a parallel trial of Linxian subjects with esophageal dysplasia who received a multivitamin /mineral supplement, suggesting an effect largely derived from nutrien ts other than those received in the present study.