LNSLNS The three letters to the editor show how difficult it is to discuss this topic in an evidence-based manner, even amongst physicians. The belief in antioxidants is deeply rooted. It does indeed sound plausible: radicals and oxidative stress—they must be harmful; anti-oxidants—these must be beneficial. Scientific studies have shown, however, that supplementation with antioxidants is ineffective in the general population; in some cases it is even harmful (e.g. vitamin E or beta-carotene in smokers). As Dr Altwein points out, this risk also exists for multivitamin preparations in association with prostate cancer. Nevertheless, some redox-active compounds—for example those present in red wine, as discussed by Dr Altwein and in our article (resveratrol)—can have health promoting effects, albeit not by their antioxidant actions, but rather, for example, by influencing gene expression.

We were aware of the criticisms on the meta-analyses of vitamin E. Therefore, we had cited a more recent analysis (Dotan et al, 2009, reference 8 in our article[1]). This analysis used a different, more robust statistical model and still came to the same result: general supplementation with vitamin E is harmful rather than beneficial.

There are no commercial diagnostic assays that can measure “oxidative stress” in a reproducible manner and with acceptable variability. Values obtained with these assays (for example, plasma lipidperoxide and malondialdehyde) often do not correlate with each other (2). Oxidative stress is not a uniform phenomenon that affects the entire body. It seems naive to assume that taking antioxidants will result in detoxification of free radicals in the entire body and therefore reduce the redox potential of all cells within the organism. Moreover, radicals and other reactive oxygen species also mediate essential body functions.

We agree with the term “alpha-tocopherol monomania” and with the statement that nature has optimally organized itself. Therefore, we believe that the resulting natural balance should not be disturbed by administering antioxidant supplements.
DOI: 10.3238/arztebl.2010.0225b

Dr. rer nat. Kirstin Wingler
Prof. Dr. med. Harald H. H. W. Schmidt
Universiteit Maastricht
Department of Pharmacology
Universiteitssingel 50
6200 MD Maastricht, Netherlands
h.schmidt@farmaco.unimaas.nl

Conflict of interest statement
Dr Wingler was employed by vasopharm GmbH, which develops inhibitors for NADPH oxidases. Professor Schmidt has received research funding from Bayer Schering und Servier. He also acts as an adviser to Bayer Schering.
1.
Wingler K, Schmidt H: Good stress, bad stress—the delicate balance in the vasculature [Guter Stress, schlechter Stress: Die feine Balance in Blutgefäßen]. Dtsch Arztebl Int 2009; 106(42): 677–84. VOLLTEXT
2.
Dotan Y, Lichtenberg D, Pinchuk I: Lipid peroxidation cannot be used as a universal criterion of oxidative stress. Prog Lipid Res 2004; 43: 200–27. MEDLINE
1. Wingler K, Schmidt H: Good stress, bad stress—the delicate balance in the vasculature [Guter Stress, schlechter Stress: Die feine Balance in Blutgefäßen]. Dtsch Arztebl Int 2009; 106(42): 677–84. VOLLTEXT
2. Dotan Y, Lichtenberg D, Pinchuk I: Lipid peroxidation cannot be used as a universal criterion of oxidative stress. Prog Lipid Res 2004; 43: 200–27. MEDLINE