Onion peel extract reduces the percentage of body fat in overweight and obese subjects: a 12-week, randomized, double-blind, placebo-controlled study

Abstract

BACKGROUND/OBJECTIVESThe anti-obesity effect of quercetin-rich onion peel extract (OPE) was suggested in rats, but information from human studies is limited. This study aimed to investigate the effects of OPE on the body composition of overweight and obese subjects.MATERIALS/METHODSIn this 12-week, randomized, double-blind, placebo-controlled study, parallel clinical trials were performed in overweight and obese Korean subjects. Randomly assigned subjects were instructed to take daily either the placebo (male, 6 and female, 30) or OPE capsules containing 100 mg of quercetin (male, 5 and female, 31). Body composition was measured by using bioimpedance and dual-energy X-ray absorptiometry (DXA). Resting energy expenditure (REE) and respiratory quotient (RQ) were evaluated by using indirect calorie measurement methods. Fasting blood levels of glucose, insulin, lipids, and leptin were determined.RESULTSQuercetin-rich OPE supplementation significantly reduced the weight and percentage of body fat as measured by DXA (P = 0.02). These effects were not shown in the control group. Levels of blood glucose (P = 0.04) and leptin (P = 0.001 for placebo, P = 0.002 for OPE) decreased in both groups. Significant increases in REE and RQ were observed in both groups (P = 0.003 for placebo, P = 0.006 for OPE) and in the OPE group alone (P = 0.02), respectively.CONCLUSIONSQuercetin-rich OPE supplementation changed the body composition of the overweight and obese subjects. This result suggests a beneficial role of the anti-obesity effect of OPE human subjects.

The Beneficial Effects of Quercetin, Curcumin, and Resveratrol in Obesity

“…Although many cell culture and animal studies focused on the beneficial effects of quercetin in obesity, there are only a limited number of human studies and clinical trials that have been performed to evaluate the effects of quercetin on obesity treatment. In a 12-week, randomized, double-blind, placebo-controlled study, Lee et al demonstrated that quercetin (100 mg/day/subject) significantly decreased the total body fat, particularly in the percentage of fat in the arm, and decreased the body mass index (BMI) of overweight or obese subjects [ 54 ]. Another study evaluated the effects of quercetin on obesity in overweight-obese subjects with various apolipoprotein E (APOE) genotypes; the authors reported that quercetin (150 mg/day/subject) decreased the waist circumference and triacylglycerol concentration [ 55 ].…”

The Effect of Onion Peel Extract on Inflammatory Mediators in Korean Overweight and Obese Women

“…Recently, Yang and Kim [19] demonstrated that the obesity index (% fat, BMI, waist circumstance) were significantly decreased by OPE intake for 12 weeks in obese university women. Previously, we reported that OPE supplementation significantly reduced the weight and percentage of body fat in overweight and obese adults [11]. We also reported that OPE supplementation significantly reduced waist and hip circumferences compared with baseline values while the changes observed in body weight and BMI were not statistically significant after 12 weeks of supplementation [12].…”

“…It has been known to have anti-diabetes, anti-obesity, and anti-hypertensive effects in animal and human studies [78910]. Recently, we reported that 12-week supplementary intake of quercetin-rich onion peel extract (OPE) significantly decreased body weight and percentage of body fat in overweight and obese adults [11]. We also have demonstrated that quercetin-rich OPE consumption for 12 weeks may exert antioxidative activity by preventing the reduction of superoxide dismutase (SOD) activity as well as the production of reactive oxygen species (ROS) in obese women [12].…”

Bioadhesive Polymeric Films Based on Red Onion Skins Extract for Wound Treatment: An Innovative and Eco-Friendly Formulation

“…All openings including donor top and receptor arm were occluded with parafilm ® to prevent solvent evaporation. At regular time intervals (5,10,15,30,45, 60, 120, 240, 300, 360, 420, 480, 1440 and 2880 min) samples of the receiving phase were withdrawn and OLE content was measured by a UV-vis spectrophotometer (UV-Visible Agilent model 8453, Agilent Technologies, Cernusco sul Naviglio MI, Italy) accomplished using a standard curve in SWF (λ max = 280.0 nm, r = 0.9998). All experiments were performed in triplicate, each result represents an average of three measurements and the error was expressed as standard deviation (±SD).…”

“…The common onion (Allium cepa L.) is a worldwide cultivated vegetable used both as food and also in the health field for the presence of bioactive molecules mainly endowed with antioxidant activity [1][2][3]. Many scientific studies on the lipid-and glucose-lowering [4][5][6][7][8], anti-inflammatory [9][10][11], antioxidant [12][13][14][15][16] and antibacterial [13] properties of onion extracts have been published. Our previous work in this area reported the pungency determination [17] and the antioxidant and immune modulatory activities of purple-skin Rojo Duro onion extracts [18].…”