Quercetin is a flavonol, an antioxidant compound many plants make. Scientists have been studying this compound since 1857. Within the last decade, they have identified a number of health benefits it can provide (Current Medicinal Chemistry, 2018). In summary, it can lower blood pressure, improve the structure of neurons and help protect the body from infection. Several readers have noted another benefit. Should you be taking quercetin for your allergies?
The Potential of Quercetin for Your Allergies:
Q. I am 63 years old and have suffered from seasonal (pollen) and environmental (dust and mold) allergies for as long as I can remember. After reading in your newspaper column about quercetin, I decided to give it a try. I am so glad that I did!
Nothing, and I mean nothing, has helped as much as taking 500 mg of quercetin twice a day. I would like to use this daily year-round to prevent nasal allergies. However, I don’t think any studies have been done to see if it is safe long-term. What is your opinion?
A. Your experience is very interesting. Quercetin is a natural flavonoid found in foods such as berries, fruits (apples, grapes), vegetables (onions, kale, broccoli, tomatoes), green tea and red wine.
Test-tube studies suggest ways quercetin calms allergic symptoms. However, we could find only a few clinical trials of quercetin for allergies. Japanese researchers used a related compound, isoquercitrin, in a study of people allergic to Japanese cedar pollen (Allergology International, Sep. 2009). This two-month placebo-controlled trial demonstrated that the compound controlled itchy, red eyes.
Italian researchers studied a supplement called Lertal® that contains quercetin along with Perilla extract and vitamin D3 (Italian Journal of Pediatrics, July 18, 2019). Children taking the supplement were much less likely to have allergy symptoms or need rescue medications than those on usual care. The researchers envision the supplement as an effective preventive treatment for allergies long term. That suggests you could comfortably continue taking quercetin for your allergies.
Other Health Benefits of Quercetin:
In addition to its role in controlling allergy symptoms, quercetin appears to improve insulin sensitivity. In the future, clinical trials will show whether it is valuable for reducing type 2 diabetes (Current Medicinal Chemistry, 2017). Most urgently, doctors are considering whether quercetin might be helpful in treating COVID-19 (Aging, March 30, 2020). Researchers have not yet conducted clinical trials to see whether this flavonol will be helpful. We discussed the possible reasons that it is interesting in this earlier post.
Have you taken quercetin for your allergies or for any other purpose? Tell us about your experience in the comment section.