Uncontrolled blood sugar can promote the production of unhealthy oxidation reactions in a person's blood. These reactions foster many diseases, such as atherosclerosis. That's why researchers have long suspected that supplementing the diet with antioxidants, such as vitamin C, would benefit people with diabetes. A study now finds that such supplements may actually promote the clogging of arteries.
David R. Jacobs Jr. of the University of Minnesota School of Public Health in Minneapolis and his colleagues evaluated cardiovascular disease in 1,923 postmenopausal women with diabetes. These individuals already had diabetes when they entered the long-running Iowa Women's Health Study, which collected data in 1986 about diets and vitamin C consumption in nearly 35,000 recruits.