Antioxidant Vitamins and Disease –
Risks of a Suboptimal Supply

This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to:    Frankp@chiro.org

FROM:   Ther. Umsch 1994 (Jul);   51 (7):   467–474

Ballmer PE, Reinhart WH, Gey KF.

Departement Medizin,
Inselspital, Universitat Bern

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Reactive oxygen species (ROS) such as the superoxide (O2.-) and the hydroxyl radical (OH.) are aggressive chemical compounds that can induce tissue injury, e.g. by peroxidation of polyunsaturated fatty acids in cell membranes or directly by DNA damage. Many pathological conditions are in part caused by ROS. There are various biological defense systems directed towards radicals: specific enzymes, e.g. superoxide dismutase or glutathion peroxidase; nonessential antioxidants, e.g. the plasma proteins and uric acid; and the essential antioxidants, e.g. vitamin C, vitamin D and carotenoids. This review focuses on various clinical conditions where ROS are of major pathogenetic significance: ageing, cancer, stroke, hematologic disorders, adult respiratory distress syndrome (ARDS) and organ preservation in transplantation medicine. Moreover, the complementary system of the vitamins C and E in defense against ROS is shortly discussed and the need for further studies about the effects of antioxidant treatment, such as interventional studies, proposed. The chronic exposure of the organism to ROS is an important factor for tissue injury in the process of ageing. Lipofuscin is a typical product of lipid peroxidation and inversely correlates with longevity of an organism. The ingestion of higher doses of antioxidative vitamins was recently shown to be protective for the development of cataracts, a degenerative disorder of the eye. The impairment of the immune system in elderly people might be prevented by a higher intake of multivitamin supplements. Whether supplementation with antioxidative vitamins can extend the life span in humans, as was shown in experimental animals, remains unanswered. High intake of vegetables and fruits is associated with a significantly lower incidence of cancer, in particular of lung, but also of laryngeal, esophageal and colorectal cancer, which might be attributed to higher intake of antioxidant vitamins. As discussed in this issue of the journal by Gey et al., there is an inverse correlation between plasma status of antioxidant vitamins and coronary mortality due to prevention of atherosclerosis. There is also an inverse correlation between the risk of suffering from a fatal stroke and the plasma concentrations of antioxidant vitamins. Supplementation with vitamin E in some hematologic disorders such as beta–thalassemia and glucose–6–phosphatase–dehydrogenase deficiency showed an improvement of hemolysis. ARDS, a common cause of respiratory failure in severly ill patients, is a 'classical free radical disease'. Interventional studies with antioxidant vitamins for the treatment of ARDS are so far lacking. Reperfusion injury by a 'radical burst' may be a major cause for performance of organ transplants such as the kidney. The treatment with multivitamin preparations containing vitamin C and E was associated with better transplant performance in kidney transplants in a recent study. In conclusion, 'optimal' plasma concentrations of essential antioxidants are a primary aim in the prevention of disease such as ischemic heart disease, stroke and cancer. This is achieved by intake of higher doses of dietary antioxidants (as compared with RDAs) or, if necessary, by vitamin supplements.

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