Updated: Dec 13, 2021
Quercetin is a natural occurring compound found in variety of plant foods such as
apples, berries, citrus fruits, red grapes, tomatoes, and onions, kale, broccoli,
cabbage, bell peppers, almonds, and olive oil. Quercetin is strong antioxidant that
has anti-inflammatory, antihistamine, antiviral properties as well as supporting
immune, cardiovascular, and gastrointestinal health.
Quercetin supplementation at doses 1000mg daily have been shown to lower the
incidence of upper respiratory infections caused from cold/flu viruses in
individuals under significant physical and mental stress. Quercetin interacts
synergistically with vitamin C and zinc to produce its antiviral activity. There is
emerging evidence to suggest that Quercetin, Vitamin C, and Zinc maybe indeed
helpful in the prevention and early treatment of Covid-19.
Quercetin has been shown block the action of histamine and other immune-
related inflammatory chemicals. Excessive histamine caused from allergies
produces a wide range of common symptoms such as cough, water eyes,
sneezing, runny nose, hives, itchy skin, gastritis, swelling, and edema. Although
the evidence is not conclusive may individuals who supplement with quercetin
find relief from seasonal allergies, gut and skin related food allergies, allergy
induced asthma, and pain and inflammation caused from osteoarthritis.
Quercetin has been widely studied in the promotion of cardiovascular health.
Diets high in this plant compound been shown to reduce the risk of death from
coronary heart disease. There are several ways that quercetin can help preventive
heart disease. For instance, quercetin at doses greater 500mg daily has been
shown to lower blood glucose levels, cholesterol levels, high blood pressure with
greatest effects seen in those with the metabolic syndrome and diabetes.
Quercetin also has anti-platelet effect and can affect metabolism of certain
prescription medications. For individuals on prescription medicines, especially on
blood thinning agents, should ideally consult with their doctor or pharmacist
before using quercetin to ensure that it is safe and appropriate.
Farid Wassef is a pharmacist who has been practice in Stouffville since 1989. Farid
is the coauthor of Breaking the Age Barrier, Strategies for Optimal Health, Energy,
and Longevity (Penguin 2003). In 2006 Farid was honoured as the Canadian
Pharmacist of Year for his excellence in patient care. He has been invited to
appear on several radio and television programs, which includes CBC, CTV, Global,
the Health Discovery Channel, and TVO concerning health promotion, disease
prevention, and the safe and effective use of prescription medicines and natural
health products. Currently, he continues to provide patient care via telephone
Farid Wassef BSc Pharm, RPh
Stouffville IDA Pharmacy