Effects of daily quercetin-rich supplementation on cardiometabolic risks in male smokers

Abstract

Limited information from human studies indicates that dietary quercetin supplementation influences blood lipid profiles, glycemic response, and inflammatory status, collectively termed cardiometabolic risks. We tested the hypothesis that quercetin-rich supplementation, derived from onion peel extract, improves cardiometabolic risk components in healthy male smokers in a randomized, double blinded, placebo-controlled parallel design. Randomly assigned subjects were instructed to take either the placebo (n = 43) or 100 mg quercetin capsules each day (n = 49) for 10 weeks. Anthropometric parameters and blood pressure were measured, and blood lipids, glucose, interleukin-6, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were determined at baseline and after 10 weeks of quercetin supplementation. Quercetin-rich supplementation significantly reduced serum concentrations of total cholesterol (P < 0.05) and LDL-cholesterol (P < 0.01), whereas these effects were not shown in the placebo group. Furthermore, significant increases were observed in serum concentrations of HDL-cholesterol both in the placebo (P < 0.005) and quercetin-rich supplementation group (P < 0.001); however, changes in HDL-cholesterol were significantly greater in subjects receiving quercetin-rich supplementation than the placebo. Both systolic (P < 0.05) and diastolic blood pressure (P < 0.01) decreased significantly in the quercetin-rich supplementation group. Glucose concentrations decreased significantly after 10 weeks of quercetin-rich supplementation (P < 0.05). In contrast, no effects of quercetin-rich supplementation were observed for the inflammatory markers-IL-6 and sVCAM-1. Daily quercetin-rich supplementation from onion peel extract improved blood lipid profiles, glucose, and blood pressure, suggesting a beneficial role for quercetin as a preventive measure against cardiovascular risk.

Protective effect of dietary flavonoid quercetin against lipemic-oxidative hepatic injury in hypercholesterolemic rats

“…Most studies have shown that quercetin has no beneficial effect on the plasma lipid profile (Yamamoto & Oue, 2006: Perez-Vizcaino & Duarte, 2010Egert et al, 2010;Zhao et al, 2011). In contrast, other studies have reported that quercetin-rich supplementation reduces serum concentrations of TC and increases serum concentrations of HDL-cholesterol (Igarashi & Ohmuma, 1995;Kamada et al, 2005;Gnoni et al, 2009;Lee et al, 2011), which cope with the results of the present study. Several explanations were suggested of how quercetin is able to influence serum lipid profile.…”

“…However, the findings of Kamada et al (2005) and Lee et al (2011), who did not detect any change in serum TG in neither normal nor diabetic rats fed with high fat diet, coped with the current results. In the same time, the findings of Fungwe et al (1992) was similar to our results in the context of increasing serum HDL-C and decreasing LDL-C (Figure 1).…”

“…Quercetin, the most abundant dietary member of this family, is present in substantial amounts in fruits and vegetables and plays an important role in human health by virtue of its antioxidant activity and its ability to modify NO levels (Lopez-Revuelta et al, 2006;Morales et al, 2006;Lee et al, 2011).…”

Effect of meat product with onion skin extract on мetabolic profile in SHR

“…Consistent with the our findings, increased HDL-cholesterol was also reported by K.H. Lee et al in healthy male smokers supplemented with quercetine from onion peel [21].…”

An Open-Label Pilot Study to Assess Honey Supplementation in Improving Lipid Profiles Among Chronic Smokers

“…This has led to an increased interest to investigate the possible beneficial effect of natural products in reducing this risk among smokers. Several studies have reported that supplementation of vitamin C-rich fruit juices for 26 days [3] as well as Quercitin-rich supplement for 10 weeks [4] significantly decreases TC and LDL levels in smokers. Honey is a natural product which contains carbohydrates such as fructose and glucose as well as organic acids, proteins, minerals and aromatic compounds [5].…”