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Antioxidant supplementation increases the risk of skin cancers in women but not in men

UMR U557 Inserm/U1125 Inra/EA3200 Cnam/Univ Paris 13, Bobigny, France 93017.
Journal of Nutrition (Impact Factor: 4.23). 10/2007; 137(9):2098-105.
Source: PubMed

ABSTRACT This research aimed to test whether supplementation with a combination of antioxidant vitamins and minerals could reduce the risk of skin cancers (SC). It was performed within the framework of the Supplementation in Vitamins and Mineral Antioxidants study, a randomized, double-blinded, placebo-controlled, primary prevention trial testing the efficacy of nutritional doses of antioxidants in reducing incidence of cancer and ischemic heart disease in the general population. French adults (7876 women and 5141 men) were randomized to take an oral daily capsule of antioxidants (120 mg vitamin C, 30 mg vitamin E, 6 mg beta-carotene, 100 microg selenium, and 20 mg zinc) or a matching placebo. The median time of follow-up was 7.5 y. A total of 157 cases of all types of SC were reported, from which 25 were melanomas. Because the effect of antioxidants on SC incidence varied according to gender, men and women were analyzed separately. In women, the incidence of SC was higher in the antioxidant group [adjusted hazard ratio (adjusted HR) = 1.68; P = 0.03]. Conversely, in men, incidence did not differ between the 2 treatment groups (adjusted HR = 0.69; P = 0.11). Despite the small number of events, the incidence of melanoma was also higher in the antioxidant group for women (adjusted HR = 4.31; P = 0.02). The incidence of nonmelanoma SC did not differ between the antioxidant and placebo groups (adjusted HR = 1.37; P = 0.22 for women and adjusted HR = 0.72; P = 0.19 for men). Our findings suggest that antioxidant supplementation affects the incidence of SC differentially in men and women.

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Available from: Khaled Ezzedine, Dec 14, 2013
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    • "Unexpectedly, in a recently published systematic review by Bjelakovic et al. on 78 randomized clinical trials on antioxidants supplementation including selenium, β-carotene, vitamin C, vitamin A, and vitamin E, not only have no favorable effects been observed, but additionally, mortality rates have risen (Bjelakovic and Gluud, 2007; Bjelakovic et al., 2012). Surprisingly, it has been shown that antioxidant supplementation may increase the risk of skin malignancy in women (Hercberg et al., 2007). There are also a number of reports, in which a history of longtime supplementation with carotenoids has increased risk of malignancy in smokers and patients with tuberculosis (Albanes et al., 1996; Omenn et al., 1996; Holick et al., 2002; Shiels et al., 2011). "
    Frontiers in Physiology 07/2014; 5:245. DOI:10.3389/fphys.2014.00245 · 3.50 Impact Factor
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    • "Recent evidence suggests that antioxidant supplements (although highly recommended by the pharmaceutical industry and taken by many individuals) do not offer sufficient protection against oxidative stress, oxidative damage or increase the lifespan. Some recent studies showed that antioxidant therapy has no effect and can even increase mortality [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53]. Schulz and coworkers showed that nutritive antioxidants completely abolish the extension of lifespan by inhibiting an adoptive reaction to ROS called mitohormesis [54]. "
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    • "The use of multivitamins/minerals (MVMs) has grown rapidly over the past several decades, and dietary supplements are now used by more than half of the adult population in the United States. On the other hand, some recent studies showed that antioxidant therapy has no effect and can even increase mortality [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37]. Ristow and coworkers showed that nutritive antioxidants completely abolish the extension of lifespan by inhibiting a process called mitohormesis [38]. "
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