Randomised clinical trial to determine the safety of quercetin supplementation in patients with chronic obstructive pulmonary disease

• Main Authors: Adam T Comstock, Fernando J Martinez, MeiLan K Han, Tyler A Barreto, Umadevi S Sajjan
• Format: Article
• Language: English
• Published: BMJ Publishing Group 2020-05-01
• Series: BMJ Open Respiratory Research
• Online Access: https://bmjopenrespres.bmj.com/content/7/1/e000392.full

IntroductionQuercetin is a plant flavonoid and has potent antioxidant and anti-inflammatory properties. In a preclinical model of chronic obstructive pulmonary disease (COPD), quercetin reduced markers of both oxidative stress and lung inflammation and also reduced rhinovirus-induced progression of lung disease. Although quercetin appears to be an attractive natural alternative to manage COPD, the safety of quercetin supplementation in this population is unknown.MethodsWe recruited COPD patients with mild-to-severe lung disease with FVE1 ranging between >35% and <80% and supplemented with either placebo or quercetin at 500, 1000 or 2000 mg/day in a dose-escalation manner. The duration of quercetin supplementation was 1 week.ResultsPatients had no study drug-related severe adverse events based on blood tests, which included both complete blood counts and evaluation of comprehensive metabolic panel. One of the patients reported mild adverse events included gastro-oesophageal reflux disease, which was observed in both placebo and quercetin groups.ConclusionsQuercetin was safely tolerated up to 2000 mg/day as assessed by lung function, blood profile and COPD assessment test questionnaire.Trial registration numberNCT01708278