23/10/2007 - Quercitin, the compound most commonly associated with onions, may reduce blood pressure by an average of five millimitres of mercury, indicates new research.
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The randomised, double-blind, placebo-controlled, crossover study, considered to be the gold-standard for experimental interventions, adds to an ever-growing body of reported health benefits for quercitin. The flavonol was previously linked to reduced risk of certain cancers.
Building on science from animal studies reporting a potential hypotensive (blood pressure lowering) role for the flavonol, researchers from the University of Utah recruited 19 men and women with pre-hypertension (average BP 137/86 mmHg) and 22 hypertensives (average BP 148/96 mmHg).
The subjects were randomly assigned to receive a daily supplement of quercetin (730 mg, USANA Health Sciences) or placebo for 28 days.
Lead author Randi Edwards and co-workers report that the hypertensives receiving the quercitin supplement experienced reductions in systolic and diastolic BP of seven and five mmHg, respectively, compared to placebo. No BP changes were observed in the pre-hypertensives as a result of either intervention.
"These data are the first to our knowledge to show that quercetin supplementation reduces blood pressure in hypertensive subjects," stated the researchers.
