Open AccessEffects of Quercetin on Blood Pressure: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials
Author(s) -
Serban MariaCorina,
Sahebkar Amirhossein,
Zanchetti Alberto,
Mikhailidis Dimitri P.,
Howard George,
Antal Diana,
Andrica Florina,
Ahmed Ali,
Aronow Wilbert S.,
Muntner Paul,
Lip Gregory Y. H.,
Graham Ian,
Wong Nathan,
Rysz Jacek,
Banach Maciej
Publication year - 2016
Publication title -
journal of the american heart association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.494
H-Index - 85
ISSN - 2047-9980
DOI - 10.1161/jaha.115.002713
Subject(s) - medicine , meta analysis , randomized controlled trial , quercetin , blood pressure , cochrane library , placebo , antioxidant , pathology , biochemistry , chemistry , alternative medicine
Background Quercetin, the most abundant dietary flavonol, has antioxidant effects in cardiovascular disease, but the evidence regarding its effects on blood pressure ( BP ) has not been conclusive. We assessed the impact of quercetin on BP through a systematic review and meta‐analysis of available randomized controlled trials. Methods and Results We searched PUBMED , Cochrane Library, Scopus, and EMBASE up to January 31, 2015 to identify placebo‐controlled randomized controlled trials investigating the effect of quercetin on BP . Meta‐analysis was performed using either a fixed‐effects or random‐effect model according to I 2 statistic. Effect size was expressed as weighted mean difference ( WMD ) and 95% CI . Overall, the impact of quercetin on BP was reported in 7 trials comprising 9 treatment arms (587 patients). The results of the meta‐analysis showed significant reductions both in systolic BP ( WMD : −3.04 mm Hg, 95% CI : −5.75, −0.33, P =0.028) and diastolic BP ( WMD : −2.63 mm Hg, 95% CI : −3.26, −2.01, P <0.001) following supplementation with quercetin. When the studies were categorized according to the quercetin dose, there was a significant systolic BP and diastolic BP ‐reducing effect in randomized controlled trials with doses ≥500 mg/day ( WMD : −4.45 mm Hg, 95% CI : −7.70, −1.21, P =0.007 and −2.98 mm Hg, 95% CI : −3.64, −2.31, P <0.001, respectively), and lack of a significant effect for doses <500 mg/day ( WMD : −1.59 mm Hg, 95% CI : −4.44, 1.25, P =0.273 and −0.24 mm Hg, 95% CI : −2.00, 1.52, P =0.788, respectively), but indirect comparison tests failed to significant differences between doses. Conclusions The results of the meta‐analysis showed a statistically significant effect of quercetin supplementation in the reduction of BP , possibly limited to, or greater with dosages of >500 mg/day. Further studies are necessary to investigate the clinical relevance of these results and the possibility of quercetin application as an add‐on to antihypertensive therapy.