Quercetin and Vitamin C Supplementation: Effects on Lipid Profile and Muscle Damage in Male Athletes

BACKGROUND: Quercetin, which is considered as a health-promoting antioxidant, belongs to the broad flavonoids group. Numerous experimental studies have proved that quercetin and vitamin C provide anti-inflammatory and antioxidant properties. The aim of this study is to assess the effects of both quercetin and vitamin C on lipid profile and muscle damage in human subjects. METHODS: A randomized, placebo-controlled, double-blind clinical trial was carried out on 60 males for eight weeks. The subjects were randomly assigned to one of the four groups: 1) quercetin + vitamin C (500 mg/day quercetin + 200 mg/day vitamin C) 2) quercetin (500 mg/day quercetin + 200 mg/day placebo) 3) vitamin C (500 mg/day vitamin C + 200 mg/day placebo) and 4) placebo (500 mg/day placebo + 200 mg/day placebo). Blood samples, body weight and percent of body fat were measured before and after intervention. In addition, dietary intake was estimated using 24-h recall. RESULTS: No significant changes occurred in high-density lipoprotein levels between groups and in the four groups before and after supplementation. Low density lipoprotein values decreased significantly (P = 0.048) in the “Quercetin + Vit C” group but decrease was not considerable in other groups before and after intervention and among groups. Fat-soluble vitamins' intake was significantly high among 4 groups. CONCLUSIONS: Quercetin and vitamin C supplementation may not be beneficial in lipid profile improvement, although it may reduce induce muscle damage and body fat percent.