Multivitamins have no impact on risk of cancer or heart disease in postmenopausal women

The largest study of its kind concludes that long-term multivitamin use has no impact on the risk of common cancers, cardiovascular disease or overall mortality in postmenopausal women. The results of the Women’s Health Initiative study, led by researchers at Fred Hutchinson Cancer Research Center, were published in the February issue of the Archives of Internal Medicine. The study focused on the effects of multivitamins because they are the most commonly used supplement. It assessed multivitamin use among nearly 162,000 women enrolled in the Women’s Health Initiative, one of the largest U.S. prevention studies of its kind and designed to address the most common causes of death, disability and impaired quality of life in postmenopausal women. The women were followed for about eight years. Nearly half of the study participants reported using multivitamins on a regular basis. Multivitamin users were more likely to be white, live in the western United States, have a lower body-mass index, be more physically active and have a college or higher degree as compared to non-users. Multivitamin users also were more likely to drink alcohol and less likely to smoke than non-users, and they reported eating more fruits and vegetables and consuming less fat than non-users. During the eight-year study period, 9,619 cases of breast, colorectal, endometrial, renal, bladder, stomach, lung or ovarian cancer were reported, as well as 8,751 cardiovascular events and 9,865 deaths. The study found no significant differences in either risk of cancer and heart disease or longevity between the multivitamin users and non-users.