Quercetin
Overview
Quercetin is a plant pigment (flavonoid). It is found in many plants and foods, such as red wine, onions, green tea, apples, berries, Ginkgo biloba, St. John's wort, American elder, and others. Buckwheat tea has a large amount of quercetin. People use quercetin as a medicine.
Quercetin is most commonly taken by mouth to treat conditions of the heart and blood vessels and prevent cancer. It is also used for arthritis, bladder infections, and diabetes. But there is limited scientific evidence to support these uses.
Coronavirus disease 2019 (COVID-19): Quercetin may have benefit for some airway infections, but there is no good evidence to support using it for COVID-19. Follow healthy lifestyle choices and proven prevention methods instead.
Classification
Is a Form of:
Plant pigment
Primary Functions:
Heart conditions, blood vessels, cancer
Also Known As:
Bioflavonoid Concentrate, Bioflavonoid Extract, Bioflavonoïde, Bioflavonoïde de Citron
How Does It Work?
Quercetin has antioxidant and anti-inflammatory effects which might help reduce inflammation, kill cancer cells, control blood sugar, and help prevent heart disease.
Uses
- Athletic performance.Most clinical research shows that taking quercetin before exercise does not decrease fatigue or improve exercise ability.
Recommended Dosing
The appropriate dose of quercetin depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for quercetin. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.
Quercetin Supplements Frequently Asked Questions
What is quercetin used for?
People use quercetin as a medicine. Quercetin is most commonly taken by mouth to treat conditions of the heart and blood vessels and prevent cancer. It is also used for arthritis, bladder infections, and diabetes.
Is Quercetin safe to take daily?
When you take it as a food, quercetin is likely safe. As a supplement, quercetin may be safe if you take reasonable amounts for a short time, such as 500 milligrams twice a day for 12 weeks.
What are the side effects of quercetin?
Common side effects of quercetin include:
- Headache (oral use)
- Numbness and tingling (oral use)
- Shortness of breath (intravenous use)
- Nausea and vomiting(intravenous use)
- Kidney damage(intravenous use greater than 945 mg/m2)
Who should not take quercetin?
You should take periodic breaks from taking quercetin. Pregnant women, breastfeeding women, and people with kidney disease should avoid quercetin. At doses greater than 1 g per day, there have been reports of damage to the kidneys.
Is CoQ10 the same as quercetin?
Antioxidants, such as coenzyme Q10 (CoQ10) and quercetin, a member of flavonoids present in red wine and tea, are thought to play a significant role in protecting cells from oxidative stress induced by reactive oxygen species (ROS).
What food has the most quercetin?
Quercetin is the most abundant flavonoid in the diet. It's estimated that the average person consumes 10–100 mg of it daily through various food sources. Foods that commonly contain quercetin include onions, apples, grapes, berries, broccoli, citrus fruits, cherries, green tea, coffee, red wine, and capers.
How quickly does quercetin work?
One published abstract 14 reported that 3 weeks of quercetin supplementation protected against mental fatigue and loss of sustained vigilance following 3 days of heavy exercise.
Does quercetin cause anxiety?
Quercetin is a bioflavonoid reported to produce variety of behavioral effects like anxiolytic, antidepressant, etc. As CRF is commonly implicated in the high-anxiety and depression, we hypothesized that quercetin may involve CRF in its anxiolytic- and antidepressant-like effects.
Does quercetin cause weight gain?
Quercetin is a flavonoid which activates oxidative metabolism. Quercetin may reduce weight gain by decreasing feed efficiency. Weight gain of the QT group decreased when compared with the PT and PS groups. Exercised groups increased cumulative caloric intake during the experimental period.
Is Quercetin an immune booster?
Appropriate nutritional supplementation can be one immune boosting strategy and one such promising product appears to be quercetin. Quercetin is a powerful antioxidant, anti-histamine and anti-inflammatory, and is the most prominent of over 5,000 flavonoid compounds found in food.
Can quercetin cause kidney damage?
Quercetin is generally considered safe. Very high doses of quercetin may damage the kidneys. You should take periodic breaks from taking quercetin. Pregnant women, breastfeeding women, and people with kidney disease should avoid quercetin.
Is Quercetin a vitamin C?
Background: Quercetin, which is considered as a health-promoting antioxidant, belongs to the broad flavonoids group. Numerous experimental studies have proved that quercetin and vitamin C provide anti-inflammatory and antioxidant properties.
Does quercetin keep you awake?
Abstract. The bioflavonoid quercetin is widely found in plants and exerts a large number of biological activities such as anti-hypertensive and anti-inflammatory properties. Therefore, the present results suggest that quercetin alters the sleep-wake cycle partly through activation of GABA(A) receptors.
What medications does quercetin interact with?
Interactions. Be careful if you are taking drugs such as antibiotics, cyclosporine, warfarin, or drugs that are changed by the liver. Quercetin may change how these drugs work and raise the risk of side effects. There don't appear to be interactions between quercetin and foods or other herbs and supplements.
Does turmeric contain quercetin?
Curcumin is a flavonoid polyphenol that is the active ingredient in the spice turmeric. Quercetin is one of the most abundant dietary flavonoids and is found in many fruits, vegetables, and beverages.
How much is too much quercetin?
Very high doses of quercetin may damage the kidneys. You should take periodic breaks from taking quercetin. Pregnant women, breastfeeding women, and people with kidney disease should avoid quercetin. At doses greater than 1 g per day, there have been reports of damage to the kidneys.
How does quercetin help immune system?
Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines, leukotrienes creation, and suppresses interleukin IL-4 production.
How much quercetin can I take daily?
If people take quercetin as a supplement, the most common dose is 500 mg per day, but some people can take up to 1,000 mg per day.
What foods contain quercetin?
Quercetin is contained in abundance in apples, honey, raspberries, onions, red grapes, cherries, citrus fruits, and green leafy vegetables [2]. Among vegetables and fruits, quercetin content is highest in onions.
Does quercetin affect thyroid?
Furthermore, quercetin decreases TSH-modulated RNA levels of the thyroid-restricted gene sodium/iodide symporter (NIS). The data raise the possibility that quercetin may be a novel disruptor of thyroid function, which has potential effects on, or use in, the therapy of thyroid diseases.
Do bananas have quercetin?
Bananas are a great source of the super-protective compounds kaempferol and quercetin. These compounds have been extensively studied, and are known to protect cells, reduce inflammation, fight numerous types of tumors, protect nerves, enhance blood circulation, and reduce the risk of a number of diseases.
Does coffee contain quercetin?
Taken together the data strongly suggests that quercetin is the major neuroprotective and anti-inflammatory component in coffee and not caffeine. Drinking 4-5 cups a day could prove beneficial as a preventative for Alzheimer's and Parkinson's disease.
Clinical Studies
- ^ ab Dietary anti-oxidant supplementation combined with Quercetin improves cycling time trial performance.
- ^ ab MacRae HS, Mefferd KM. Dietary antioxidant supplementation combined with quercetin improves cycling time trial performance. Int J Sport Nutr Exerc Metab. (2006)
- ^Yoo KS, Lee EJ, Patil BS. Quantification of quercetin glycosides in 6 onion cultivars and comparisons of hydrolysis-HPLC and spectrophotometric methods in measuring total quercetin concentrations. J Food Sci. (2010)
- ^ ab Arabbi PR, Genovese MI, Lajolo FM. Flavonoids in vegetable foods commonly consumed in Brazil and estimated ingestion by the Brazilian population. J Agric Food Chem. (2004)
- ^Careri M, et al. Direct HPLC analysis of quercetin and trans-resveratrol in red wine, grape, and winemaking byproducts. J Agric Food Chem. (2003)
- ^Zhang F, et al. Microwave-assisted extraction of rutin and quercetin from the stalks of Euonymus alatus (Thunb.) Sieb. Phytochem Anal. (2009)
- ^Jeong EJ, et al. Inhibitory constituents of Euonymus alatus leaves and twigs on nitric oxide production in BV2 microglia cells. Food Chem Toxicol. (2011)
- ^Goo HR, Choi JS, Na DH. Simultaneous determination of quercetin and its glycosides from the leaves of Nelumbo nucifera by reversed-phase high-performance liquid chromatography. Arch Pharm Res. (2009)
- ^Wang FM, Yao TW, Zeng S. Determination of quercetin and kaempferol in human urine after orally administrated tablet of ginkgo biloba extract by HPLC. J Pharm Biomed Anal. (2003)
- ^Murota K, et al. alpha-Oligoglucosylation of a sugar moiety enhances the bioavailability of quercetin glucosides in humans. Arch Biochem Biophys. (2010)
- ^ ab Abbey EL, Rankin JW. Effect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammation. Int J Sport Nutr Exerc Metab. (2011)
- ^Santos MR, et al. Influence of the metabolic profile on the in vivo antioxidant activity of quercetin under a low dosage oral regimen in rats. Br J Pharmacol. (2008)
- ^Ravichandran S1, et al. Pharmacophore model of the quercetin binding site of the SIRT6 protein. J Mol Graph Model. (2014)
- ^ ab Yasuda M, et al. Synthesis and characterization of SIRT6 protein coated magnetic beads: identification of a novel inhibitor of SIRT6 deacetylase from medicinal plant extracts. Anal Chem. (2011)
- ^Absorption of dietary quercetin glycosides and quercetin in healthy ileostomy volunteers.
- ^ ab Kaushik D, et al. Comparison of Quercetin Pharmacokinetics Following Oral Supplementation in Humans. J Food Sci. (2012)
- ^Influence of fatty acid patterns on the intestinal absorption pathway of quercetin in thoracic lymph duct-cannulated rats.
- ^Pacifici GM. Inhibition of human liver and duodenum sulfotransferases by drugs and dietary chemicals: a review of the literature. Int J Clin Pharmacol Ther. (2004)
- ^Harris RM, Waring RH. Sulfotransferase inhibition: potential impact of diet and environmental chemicals on steroid metabolism and drug detoxification. Curr Drug Metab. (2008)
- ^ ab c Cheuvront SN, et al. No effect of nutritional adenosine receptor antagonists on exercise performance in the heat. Am J Physiol Regul Integr Comp Physiol. (2009)
- ^Egert S, et al. Daily quercetin supplementation dose-dependently increases plasma quercetin concentrations in healthy humans. J Nutr. (2008)
- ^ ab c Quercetin Reduces Blood Pressure in Hypertensive Subjects.
- ^ ab Youdim KA, et al. Flavonoid permeability across an in situ model of the blood-brain barrier. Free Radic Biol Med. (2004)
- ^Graefe EU, et al. Pharmacokinetics and bioavailability of quercetin glycosides in humans. J Clin Pharmacol. (2001)
- ^ ab Tissue Distribution of Quercetin in Pigs after Long-Term Dietary Supplementation.
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- ^Protective Effects of Quercetin and Vitamin C against Oxidative Stress-Induced Neurodegeneration.
- ^Sasaki N, et al. Protective effects of flavonoids on the cytotoxicity of linoleic acid hydroperoxide toward rat pheochromocytoma PC12 cells. Chem Biol Interact. (2003)
- ^Kim H, et al. Effects of naturally occurring compounds on fibril formation and oxidative stress of beta-amyloid. J Agric Food Chem. (2005)
- ^Shirai M, et al. Effect of a conjugated quercetin metabolite, quercetin 3-glucuronide, on lipid hydroperoxide-dependent formation of reactive oxygen species in differentiated PC-12 cells. Free Radic Res. (2006)
- ^Time-dependent protective and harmful effects of quercetin on 6-OHDA-induced toxicity in neuronal SH-SY5Y cells.
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- ^Glial metabolism of quercetin reduces its neurotoxic potential.
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- ^Resveratrol protects dopaminergic neurons in midbrain slice culture from multiple insults.
- ^Chen JC, et al. Inhibition of iNOS gene expression by quercetin is mediated by the inhibition of IkappaB kinase, nuclear factor-kappa B and STAT1, and depends on heme oxygenase-1 induction in mouse BV-2 microglia. Eur J Pharmacol. (2005)
- ^Kwon YS, et al. Modulation of suppressive activity of lipopolysaccharide-induced nitric oxide production by glycosidation of flavonoids. Arch Pharm Res. (2004)
- ^Bureau G, Longpré F, Martinoli MG. Resveratrol and quercetin, two natural polyphenols, reduce apoptotic neuronal cell death induced by neuroinflammation. J Neurosci Res. (2008)
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- ^Davis JM, et al. Quercetin increases brain and muscle mitochondrial biogenesis and exercise tolerance. Am J Physiol Regul Integr Comp Physiol. (2009)
- ^Davis JM, et al. The dietary flavonoid quercetin increases VO(2max) and endurance capacity. Int J Sport Nutr Exerc Metab. (2010)
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- ^Inhibition of heat shock factor activity prevents heat shock potentiation of glucocorticoid receptor-mediated gene expression.
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- ^Liu WL, et al. Protective effects of heat shock protein70 induced by geranylgeranylacetone in atrophic gastritis in rats. Acta Pharmacol Sin. (2007)
- ^Ciftci O, et al. Quercetin prevents 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced testicular damage in rats. Andrologia. (2011)
- ^Ciftci O, Ozdemir I. Protective effects of quercetin and chrysin against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced oxidative stress, body wasting and altered cytokine productions in rats. Immunopharmacol Immunotoxicol. (2011)
- ^Ciftci O, et al. Ameliorating effects of quercetin and chrysin on 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced nephrotoxicity in rats. Toxicol Ind Health. (2011)
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- ^Enkhmaa B, et al. Mulberry (Morus alba L.) leaves and their major flavonol quercetin 3-(6-malonylglucoside) attenuate atherosclerotic lesion development in LDL receptor-deficient mice. J Nutr. (2005)
- ^Puangpraphant S, de Mejia EG. Saponins in yerba mate tea ( Ilex paraguariensis A. St.-Hil) and quercetin synergistically inhibit iNOS and COX-2 in lipopolysaccharide-induced macrophages through NFkappaB pathways. J Agric Food Chem. (2009)
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