Quercetin
Quercetin is compound found naturally in many plants offering health benefits in allergic conditions, immunity, cardiovascular system, diabetes, conditions involving inflammation and general health. This nutritional flavonoid is a potent antioxidant – considered more so than that of vitamin C and E.
Quercetin is found in high sources in grapes, berries, cherries, apples, citrus fruits, onions, buckwheat, kale, tomatoes, red wine, garlic, and black tea with concentration of quercetin varying from one plant to another. Although food sources are valuable for their phytochemical and antioxidant activity, a standardized supplement containing a guaranteed specified content of quercetin can provide a more beneficial affect for health conditions [1].
Health benefits of quercetin
The phytochemical activity of quercetin makes it a valuable therapeutic product which can help in many areas involving the immune system, allergic reactions such as allergic rhinitis and atopic eczema; inflammatory conditions in the body; diabetes and sugar control, cardiovascular system and blood vessel health.
As an antioxidant and anti-inflammatory
The significant antioxidant value of quercetin are extremely valuble in the reduction of free radical damage involved in many chronic diseases [2]. Antioxidants are compounds which bind to and neutralize free radicals – these guys are unstable molecules which may cause damage to our cells if their levels become too high. Free radical damage has been linked to many chronic diseases – such as heart disease, dementia, arthritis, autoimmune disorders, chronic inflammation and diabetes. High levels of free radical may also increase the inflammatory response.
Although inflammation is needed for the body to be able to fight disease, heal and repair, when healing process continues without resolution, a chronic inflammatory chronic condition can result. Chronic inflammation is associated with many health problems – such as heart disease, diabetes, obesity, arthritis and autoimmune disorders. Reducing inflammation will allow the body to proceed through its normal healing process.
Allergies
Quercetin offers anti-allergic activity through functions that are known for inhibiting histamine production and pro-inflammatory mediators. This action can be beneficial for allergic diseases such as atopic dermatitis, allergic rhinitis and asthma [3].
Quercetin may offer relief for symptoms associated with allergic reactions.
Sugar control
Quercetin offers antihyperglycemic action – which means it counteracts accumulated sugar in the blood. Mechanisms proposed for this action include improvement of insulin sensitivity, promote the storage of glucose in the muscles and liver and improve insulin resistance. Other benefits obtained from quercetin for diabetics may include: improved reproduction function (sexual dysfunction and infertility). Diabetic retinopathy can be associated with oxidative stress, inflammation, retinal venous damage and neurodegeneration. Quercetin may reduce oxidative damage and inflammation reducing the risk of diabetic retinopathy and other associated eye disorders.
Autoimmune disorders
Autoimmune disorders are disorders in which the body's immune system attacks its own healthy cells. Many autoimmune disorders involve chronic inflammation such as rheumatoid arthritis and lupus. Reducing inflammation in these conditions can help with symptom relief. In a randomized, double-blind, placebo-controlled clinical trial in which 50 women with RA were allocated into a quercetin (500 mg/day) was shown to significantly improve symptoms and disease activity [4].
Degenerative brain disorders
In degenerative brain disorders - such as Alzheimer’s disease and dementia, quercetin may protect against free radical stress and inflammation, and by promoting neurogenesis (the growth and development of new nerve cells) (5).
Cardiovascular health
There are numerous studies which have shown a diet high in flavonoid-rich foods (fruit and vegetables) lowers the risk of death through cardiovascular disease (CVD). Quercetin is found in many fruits, vegetables, nuts and seeds and is thought to lower the risk of CVD by reducing the incidence of vascular endothelial dysfunction.
The vascular endothelium is the physical barrier between circulating blood and tissue. It regulates vascular tone and modulates coagulation, inflammation and immunity – essential functions for a healthy cardiovascular system. Chronic age-related diseases of the arteries and heart (CVD) are associated with endothelial dysfunction [6,8].
Quercetin may also lower the risk of endothelial dysfunction and its risk factors through its anti-atherosclerotic and anti-hypertensive effects.
Gouty arthritis
Hyperuricemia refers to high levels of uric acid in the blood. Uric acid is a by-product of the metabolism of purine-rich foods. It is usually excreted through urine via the kidneys, however this process is inefficient for some people and can result in the formation of uric acid crystals in joints and organ - causing pain and inflammation. Quercetin may offer benefits as a preventative and management treatment which can be combined with conventional drugs or used alone. What makes quercetin suitable is its antioxidant, anti-inflammatory and anti-hyperuricemia actions. It has been shown to ameliorate metabolic syndrome and cardiovascular diseases which are disorders association with gout [7].
Quercetin may be beneficial for the prevention and treatment of hyperuricemia and gouty arthritis.
Immunity
Quercetin can stimulate the immune system, offers antiviral, anti-allergic (inhibiting histamine release), and reducing inflammatory activity [9].
To summarize
Quercetin is a compound found in many natural foods such as fruits, vegetables, nuts, seeds and available as a supplement. It offers high antioxidant and anti-inflammatory activity making it beneficial for many health concerns such as stimulating immune function, inhibiting histamine release in allergic reactions and may reduce inflammation in many chronic conditions.
The information provided is not intended to be used for diagnosis or treatment. If you are experiencing any health concerns, please consult your doctor for advice.
References
- [1] Therapeutic Potential of Quercetin: New Insights and Perspectives for Human Health https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254783/
- [2] Quercetin, Inflammation and Immunity https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808895/
- [3] Quercetin with the potential effect on allergic diseases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7227109/
- [4] The Effect of Quercetin on Inflammatory Factors and Clinical Symptoms in Women with Rheumatoid Arthritis: A Double-Blind, Randomized Controlled Trial https://pubmed.ncbi.nlm.nih.gov/27710596/
- [5] Mechanistic insights and perspectives involved in neuroprotective action of quercetin https://www.sciencedirect.com/science/article/pii/S0753332221005114?via%3Dihub
- [6] Selected Plant-Derived Polyphenols as Potential Therapeutic Agents for Peripheral Artery Disease: Molecular Mechanisms, Efficacy and Safety https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611444/
- [7] A review on benefits of quercetin in hyperuricemia and gouty arthritis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9315272/
- [8] Therapeutic Potential of Quercetin to Alleviate Endothelial Dysfunction in Age-Related Cardiovascular Diseases https://www.frontiersin.org/articles/10.3389/fcvm.2021.658400/full
- [9] Quercetin and Its Anti-Allergic Immune Response https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273625
This article is for informational purposes only and does not provide medical advice, diagnosis, or treatment. Any information published on this website or by this brand is not intended as a substitute for medical advice. If you have any concerns or questions about your health you should consult with a health professional.