Is quercetin helpful for a specific condition? I see it as an ingredient in several different types of supplements.

Answer:

Quercetin is a yellow flavonoid that occurs in small amounts in the form of rutin in foods like capers, onions, and kale. It also naturally occurs in plants, like Ginkgo biloba, St. John's wort, and sea buckthorn.

As discussed in more detail in our Quercetin Supplements Review (which includes tests of products and our Top Picks among quercetin supplements), preliminary evidence suggests that quercetin may be helpful to men with prostatitis, which is why it is added as an ingredient in some prostate supplements, although these combinations have typically not been clinically tested. It may also have modest benefit in rheumatoid arthritis and insulin resistance, and one small clinical study found that quercetin helped improve word-recall memory when taken with resveratrol. Quercetin may also modestly reduce blood pressure.

Although quercetin is commonly promoted for a wide range of other uses - including allergies, asthma and cardiovascular disease - the evidence supporting these uses is limited.