To the Editor.
—The May 11 issue of JAMA1 contains a two-page advertisement representing that the "antioxidant" vitamins are pure antioxidants and, therefore, helpful against coronary artery disease.In fact, they are redox agents, antioxidant in some circumstances, pro-oxidant in others. When present in physiological (recommended daily allowance [RDA]) amounts and when part of the balanced biochemistry of the more than 150 redox and nonredox chemicals in each fruit or vegetable, they tend to be antioxidant. When present in the pharmacologic (above-RDA) amounts found in supplements, they are unbalanced biochemistry, tend to be pro-oxidant, and also have many chemical actions unrelated to vitamin or redox activity. We reviewed these facts in 1994 in detail2 and succinctly,3 and we cited studies reporting harms from above-RDA amounts of "antioxidant" vitamins, including promotion of heart disease, cancer, and liver and kidney disease.The nonvitamin prohemorrhagic effect of pharmacologic (above-RDA) supplements
Herbert V. Antioxidants, Pro-oxidants, and Their Effects. JAMA. 1994;272(21):1659. doi:10.1001/jama.1994.03520210043027