Effects of total vitamin a, vitamin c, and fruit intake on risk for metabolic syndrome in korean women and men

Objectives: The question of whether the consumption of antioxidants prevents and alleviates metabolic syndrome (MetS) by reducing insulin resistance remains controversial. The aim of this study was to assess whether the intake of vitamin A (including β-carotene), vitamin C, fruits, or vegetables was negatively associated with MetS in Korean adults aged≥20y. Methods: We conducted a cross-sectional study of 27,656 adults ≥20y of age who participated in the 2007-2012 Korean National Health and Nutrition Examination Survey. Daily intake of vitamin A and vitamin C was assessed by 24-h recall, and the consumption of fruits and vegetables was determined using a food frequency questionnaire. Odds ratios (ORs) for MetS were calculated for log₂-transformed vitamin A and C intake values and for the interaction of sex with vitamin A and C intake, after covariate adjustment. Results: Interactions were seen between total vitamin A and C intake and sex for MetS. With a twofold increase in total vitamin A and C intake in women, the ORs (95% confidence intervals) for metabolic syndrome were 0.942 (0.901-0.985) and 0.933 (0.883-0.987), indicating decreases of 5.8% and 6.7% in MetS, respectively. There were no equivalent decreases in men. Women in the second and highest tertiles of fruit intake exhibited 17.5% and 21.8% lower incidences of MetS, respectively, compared with women in the lowest tertile. Conclusions: The intake of total vitamin A and C, as well as moderate and high fruit intake, may have alleviated MetS in women, but not in men, in a representative sample of the general South Korean population.