Quercetin is a flavonoid antioxidant found in pigmented fruits and vegetables. Berries, onions, grapes and apples all provide good dietary sources of quercetin. Lab studies have shown that quercetin may benefit heart health and may also help to prevent allergy symptoms as well as cancer (UMMC). Talk to your doctor or dietician to learn more about how quercetin-containing foods may help you to maintain optimal health.
The University of Maryland Medical Center explains that quercetin has anti-inflammatory and antihistamine properties that may help to reduce allergy symptoms. Quercetin may also help to prevent cancer, and it may provide benefits for the heart and circulatory system, as the antioxidant properties of quercetin may help to reduce levels of LDL cholesterol. Quercetin supplements have also been shown to reduce blood pressure in people with hypertension.
Fruits and vegetables are a good natural source of quercetin. According to the University of Maryland Medical Center and "Psychology Today," citrus fruits, apples, parsley, red wine and tea all contain quercetin. Dark pigmented fruits such as berries and olives also provide quercetin. Quercetin supplements are available at most health food stores but may have adverse effects if taken in large quantities or used over a long period of time.
Apples supply a significant dietary source of quercetin, according to a report in Psychology Today. The U.S. Department of Agriculture finds that fresh, whole apples supply about 4.4 milligrams of quercetin for every 100 grams of apple. As a medium-sized apple is typically about 150 grams, apples may contain up to about 10 milligrams of quercetin each. To optimize quercetin content, it is important to also eat their pigment-rich skin. Apples without skin contain less than half the amout of quercetin as whole apples. Apple juice typically contains less than one-tenth the amount of quercetin in a whole apple.
Talk to your doctor to learn more about how a diet rich in fruits and vegetables can help you to maintain optimal health. As noted by "Psychology Today," diets rich in flavonoids such as quercetin may have protective benefits for your brain as well your heart. Nutrition scientists such as Chang Y. Lee advocate adding natural sources of quercetin to your diet rather than taking quercetin supplements, which may be harmful if taken in large quantities or in combination with certain medications.