What is Quercetin?
What do blueberries, red wine and kale all have in common? They all contain quercetin, a natural plant compound that offers benefits essential for longevity, healthy hearts, strong immune systems and so much more.
Quercetin comes from plants and can be found in many different vegetables, fruits, leaves and grains. Examples include tea, onions, berries, parsley and many spices like turmeric. Quercetin is highly anti-inflammatory, can alleviate allergies and even reduce body fat.
Quercetin is what’s known as a flavonoid. Flavonoids are actually responsible for giving fruits and vegetables their bright colors. Over 6 thousand flavonoids have been discovered so far, and quercetin is one of the better-known ones. Because diets that are rich in fruits and vegetables have been shown to provide various health benefits, including a decreased risk of cancer and heart disease, scientists are spending more time exploring the way flavonoids work.
You’ve probably heard the exhortation to ‘eat the rainbow,’ meaning that you should consume a variety of fresh fruits and vegetables each day. You can thank flavonoids for making it easy to spot the superfoods that are brimming with healthful compounds. Flavonoids belong to a class of plant chemicals called polyphenols. Besides giving a plant its color, polyphenols also help to protect it against various threats. When we eat plants, we get the same benefits as the plant.
One of the biggest benefits of quercetin is its antioxidant effect. Antioxidants prevent damage to cells from things like smoking, pollution, poor quality food, as well as the waste products of your body’s metabolism. Flavonoids, including quercetin, are believed to reduce the risk of serious chronic diseases such as heart disease.
Heart disease is the top killer of both men and women in the United States and many other countries around the world. About one-quarter of all deaths in the U.S. are due to heart disease. This translates to roughly 610,000 people each year (x). The antioxidant and anti-inflammatory effects of quercetin dihydrate, however, may help prevent cardiovascular diseases. It may also reduce the risk of atherosclerosis (hardening of the arteries) by protecting the arteries from damage by free radicals, as well as improve the quality of the arterial walls (x).
Research has shown a link between an increased intake of flavonoids like quercetin and a lowered risk of cardiovascular disease. This potential holds true across a variety of demographics (x). Quercetin may also be effective against blood clots. While it is necessary for blood to clot in the event of a cut or other injury, it is not healthy to have blood build up inside the body. This build-up or ‘platelet aggregation’ is known to lead to stroke and other problems. However, quercetin may lower the risk of developing blood clots (x).
Another possible advantage of quercetin is its ability to fight colds. It may also fight against the development of colds and other upper respiratory infections following intensive exercise (x).
A third positive respiratory effect of quercetin is in soothing allergy symptoms. Itching, sneezing, a stuffy, runny nose and congestion can make allergy sufferers miserable, but quercetin has been shown to alleviate many allergy symptoms in various studies (x).
Cholesterol gets a bad rap, but it’s part of every cell in your body. It’s a wax-like substance that is made in the liver and is used to make things like hormones and bile. In fact, your organs and brain need it to function properly. Doctors and scientists now recognize that there are different types of cholesterol and some are better to have than others, but what’s important to remember is that some cholesterol is necessary for good health. Of course, too much has been associated with many serious problems from heart disease to Alzheimer’s to stroke.
Quercetin has shown promise in early research for lowering total cholesterol as well as triglyceride levels. It has also been linked to decreased amounts of inflammatory proteins that lead to hardening of the arteries. Human studies have delivered similar improvements, with lower LDL (‘bad’) cholesterol and increased HDL (‘good’) cholesterol (x).
Finding the fountain of youth has long been a goal of the human race. While quercetin is no magic bullet, it is something simple you can take to help live a longer, healthier life. A large study over 25 years found that men who ate flavonoids like quercetin significantly increased longevity. Research suggests that flavonoids may have up to a 25 percent influence over risk factors such as cancer and coronary heart disease (x).
There are many great aspects about living in the modern age, but a sedentary lifestyle isn’t one of them. Sitting around too much leads to a sluggish metabolism. A supplement of quercetin can help rev up your metabolism in a number of ways. While human studies are still necessary, animal research showed that a quercetin supplement helped subjects to lose weight without making any changes to diets (x).
Quercetin’s anti-inflammatory and antioxidant qualities also help you lose weight. Many obese people have chronic low-grade inflammation, and quercetin has been shown to calm the inflammatory response. It also fires up your fat burners, inhibits fat storage and gets your metabolism moving again. Researchers have studied the effects of several flavonoids on weight and found that participants who took quercetin typically lost the most weight (x).
Protection from Diabetes
Because of quercetin’s ability to lower levels of a sugar called sorbitol that builds up in kidney cells, nerve cells and the eyes of those with type 2 diabetes, scientists believe quercetin may help prevent damage to those organs. More research is necessary in humans, but early animal studies show promising results using quercetin to lower blood sugar (x).
About 10 percent of people worldwide suffer from some form of chronic kidney disease (CKD). Millions die from CKD each year. Fibrosis is a condition in which there is an excess growth of fibers resulting in thickening of tissue. Fibrosis happens with more or less all kidney diseases, but quercetin has been shown in studies to reduce the amount of fibrosis and improve healing of the kidneys (x).
In another study, a combination of quercetin and curcumin along with anti-rejection medication revealed improved kidney functioning following transplants (x).
Prostatitis is inflammation of the prostate gland. It is estimated that at least 10 percent of all men will experience prostatitis symptoms in their lifetime and it accounts for some 2 million doctor visits each year in the U.S. alone. Research shows that quercetin seems to reduce pain and improve the quality of life of men with inflamed prostates (x).
Quercetin Side Effects
Most people experience no side effects with quercetin, but some individuals have reported headache and/or tingling in the limbs. For those with sensitive digestion, quercetin may cause stomach upset, acid reflux, heartburn and indigestion. Some users report sweating and flushed skin. More serious side effects include cramping, nausea and vomiting. Quercetin dihydrate is best taken with food and/or fluids to lower the risk of side effects.
It’s possible to have an allergic reaction to quercetin. Symptoms include itching, rash, hives, difficulty breathing, wheezing, mouth sores and potential swelling of the lips, tongue or throat.
Extremely high doses may damage the kidneys.
Quercetin is safe for most people to use. When taking a quercetin supplement, namely quercetin dihydrate, take 250 to 500 mg once or twice daily with food. Of course, if a medical professional suggests an alternative dosage, it is best to follow his/her instructions.
Because it uses the same receptors as antibiotics, quercetin may interfere with the absorption and effect of these drugs. Quercetin has also been shown to interfere with the action of a breast cancer medicine called Taxol. If you’re taking any medications, it’s best to talk to your doctor before adding a quercetin dihydrate supplement to your diet.
Due to its color (bright yellow), it can stain like turmeric, so take caution not to spill it.
If you’re pregnant or planning to become pregnant, talk to your doctor before adding a quercetin supplement to your health regimen.
The Bottom Line
Quercetin is a powerful antioxidant and anti-inflammatory that can help reduce your risk of serious illness such as cancer and heart disease. It can potentially alleviate more ordinary complaints like the common cold and allergy symptoms. Used in moderation, it can possibly improve your day-to-day life, as well as increase your longevity.