Effects of long-term antioxidant supplementation and association of serum antioxidant concentrations with risk of metabolic syndrome in adults.
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.


OBJECTIVE
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.


METHODS
Adults (n = 5220) participating in the SUpplementation en VItamines et Minéraux 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).


CONCLUSIONS
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.
Czernichow
Sébastien
S
Nutritional Epidemiology Research Unit-UMR U557 INSERM, U1125 INRA, CNAM, PARIS 13 University, 93017 Bobigny, France. czernichow@uren.smbh.univ-paris13.fr
Vergnaud
Anne-Claire
AC
Galan
Pilar
P
Arnaud
Josiane
J
Favier
Alain
A
Faure
Henri
H
Huxley
Rachel
R
Hercberg
Serge
S
Ahluwalia
Namanjeet
N
D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D008875:Middle Aged; D008903:Minerals / Q000008:administration & dosage* / Q000097:blood; D016017:Odds Ratio; D012307:Risk Factors; D012643:Selenium / Q000008:administration & dosage / Q000097:blood; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood; D014815:Vitamins / Q000008:administration & dosage* / Q000097:blood; D015032:Zinc / Q000008:administration & dosage / Q000097:blood; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood
D000975:Antioxidants; D008903:Minerals; D014815:Vitamins; D019207:beta Carotene; D014810:Vitamin E; D012643:Selenium; D015032:Zinc; D001205:Ascorbic Acid