International Journal of Preventive Medicine (Int J Prev Med)2008-7802112013033111211121ENFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranChild Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, IranFood Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran20130331<p class="Pa7"><strong>Background: </strong>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.</p> <p class="Pa7"><strong>Methods: </strong>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.</p> <p class="Pa7"><strong>Results: </strong>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 (<em>P </em>= 0.048) in the &ldquo;Quercetin + Vit C&rdquo; group but decrease was not considerable in other groups before and after intervention and among groups. Fat‑soluble vitamins&rsquo; intake was significantly high among 4 groups.</p> <p class="Pa7"><strong>Conclusions: </strong>Quercetin and vitamin C supplementation may not be beneficial in lipid profile improvement, although it may reduce induce muscle damage and body fat percent.</p> <p class="Pa7"><strong>Keywords: </strong>Athletes, lipid profiles, quercetin</p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1121http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1121/849