Positive Health Online

Abstract

CZEMICHOW and COLLEAGUES,  Nutritional Epidemiology Research Unit-UMR U557 INSERM, U1125 INRA, CNAM, PARIS 13 University, 93017 Bobigny, France. czernichow@uren.smbh.univ-paris13.fr examine the effect of antioxidant supplementation for 7.5 y on the incidence of metabolic syndrome (MetS and the epidemiologic association between baseline serum antioxidant concentrations and the prospective risk of MetS.

Background

Limited observational evidence suggests lower antioxidant concentrations in individuals with the metabolic syndrome (MetS); few randomized controlled trials have addressed the effect of multiple antioxidants on the risk of MetS.

Methodology

The objective was to examine the effect of antioxidant supplementation for 7.5 y on the incidence of MetS and the epidemiologic association between baseline serum antioxidant concentrations and the prospective risk of MetS. Design: Adults (n = 5220) participating in the Supplementation en VItamines et Mineraux AntioXydants (SU.VI.MAX) primary prevention trial were randomly assigned to receive a supplement containing a combination of antioxidants (vitamins C and E, beta-carotene, zinc, and selenium) at nutritional doses or a placebo. Subjects were free of MetS at baseline and were followed for 7.5 y.

Results

Antioxidant supplementation for 7.5 y did not affect the risk of MetS. Baseline serum antioxidant concentrations of beta-carotene and vitamin C, however, were negatively associated with the risk of MetS; the adjusted odds ratios (and 95% CIs) for the highest compared with the lowest tertile were 0.34 (0.21, 0.53; P for trend = 0.0002) and 0.53 (0.35, 0.80; P for trend = 0.01), respectively. Baseline serum zinc concentrations were positively associated with the risk of developing MetS; the adjusted odds ratio (and 95% CI) for the highest compared with the lowest tertile was 1.81 (1.20, 2.72; P for trend = 0.01).

Conclusion

The experimental finding of no beneficial effects of antioxidant supplementation in a generally well-nourished population is consistent with recent reports of a lack of efficacy of antioxidant supplements. However, the relations observed between the risk of MetS and baseline serum antioxidant concentrations, which probably reflect associations with overall dietary patterns, do support the current recommendations to consume antioxidant-rich foods. This trial was registered at clinicaltrials.gov as NCT00272428.

References

Czernichow S.  Vergnaud AC.  Galan P.  Arnaud J.  Favier A.  Faure H.  Huxley R.  Hercberg S and Ahluwalia N. Effects of long-term antioxidant supplementation and association of serum antioxidant concentrations with risk of metabolic syndrome in adults. American Journal of Clinical Nutrition. 90(2): 329-35. Aug 2009.