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New Clinical Trial Shows Benefit and Safety of Quercetin in Early Cv19: International Journal of General Medicine 2021 Jun
This is a modestly-sized real-world clinical trial that 1) demonstrates safety, 2) suggests efficacy, and 3) will have to be followed by additional research
DrV summary: Quercetin is an antioxidant and antiinflammatory bioflavonoid pigment found in many fruits and vegetables; daily dietary intake in Westerners is 6-18 milligrams (mg) per day. Per this study, Quercetin 400 mg per day 1) is safe for persons with early/mild Cv19 and 2) appears to provide clinical benefits including “reduction in frequency and length of hospitalization, in need of non-invasive oxygen therapy, in progression to intensive care units and in number of deaths” along with “possible anti-fatigue and pro-appetite properties”
Title: Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study
Citation: International Journal of General Medicine 2021 Jun 10.2147/IJGM.S318720
Clinical trial and intervention: 152 patients with mild Cv19: half received standard treatment and half received standard treatment + quercetin, 2 tablets per day of quercetin 200 mg each tablet for a total dose of quercetin 400 mg per day for 30 days in the form of a sunflower lecithin phytosome, which supposedly increases absorption/bioavailability of the quercetin
Overall impression: Reasonable study and reasonable conclusions. I get the impression that the authors tried to do good work; their rationale and design are good, and they accounted for changes, mistakes, and surprises. They acknowledge that their randomization procedure resulted in an imbalanced partitioning of comorbid patients in the standard treatment group (“Patients with comorbidities were 45 out of 76 in the SC [standard care] group and 29 out of 76 in the QP [quercetin phytosome] group.”), and this imbalance favored the appearance of better efficacy among the patients that received quercetin; that’s fine because this was a first/preliminary study anyway and was not going to be conclusive regardless.
Overstatements/understatements from the authors: At least two of the authors have financial conflicts of interest in that they appear to benefit from sales of quercetin phytosome; that’s acceptable and to be expected in self-funded research and probably contributed to a modest amount of hyperbole but all-in-all the study remains valid for what it is: a modestly-sized real-world clinical trial that 1) demonstrates safety, 2) suggests efficacy, and 3) will have to be followed by additional research. The authors unfortunately sang the corporate refrain of vaccine necessity and ivermectin inefficacy, both of which are objectively false.
What conclusions and actions can be drawn from this?: Clear safety + suggestion of clinical benefit + additional collateral benefits = reasonable adjunctive preventive/treatment intervention
Context and related works: Given that ~60% of the world population is deficient in vitamin D and 30% are deficient in zinc, these other treatments should be used with quercetin and likely deserve priority over the exclusive use of quercetin, especially if the latter is proprietary/expensive. Co-administration of zinc and quercetin is likely to have additive/synergistic benefits due to quercetin’s ability to enhance cellular uptake of zinc. See my free-access Antiviral Nutrition Course and books Antiviral Nutrition (PDF download) / Antiviral Strategies and Immune Nutrition (paper book) for additional details.
Dr Alex Kennerly Vasquez (introduction; brief Bio-CV) writes and teaches for an international audience on various topics ranging from leadership to nutrition to functional inflammology. Major books include Inflammation Mastery, 4th Edition (full-color printing, 1182 pages, equivalent to 25 typical books [averaging 60,000 words each]), which was also published in two separate volumes as Textbook of Clinical Nutrition and Functional Medicine (Volume 1: Chapters 1-4; Volume 2: Chapter 5—Clinical Protocols for Diabetes, Hypertension, Migraine, Fibromyalgia, Rheumatoid Arthritis, Psoriasis, Vasculitis, Dermatomyositis and most other major inflammatory/autoimmune disorders); several sections have been excerpted including Antiviral Strategies and Immune Nutrition (ISBN 1502894890) (aka, Antiviral Nutrition [available as PDF download] and Brain Inflammation in Chronic Pain, Migraine, and Fibromyalgia. Dr Vasquez’s books are available internationally via bookstores such as BookDepository, Amazon.com, Barnes and Noble, ThriftBooks, AbeBooks, BetterWorldBooks, WaterStonesBooks and his new Telegram channel is https://t.me/DrAlexVasquez.