Quercetin is a natural extract belonging to the flavonoid family, a vegetable pigment that is found in different foods and plants and that has been attracting a lot of interest as a nutraceutical supplement for several years. The properties of quercetin make it a real antioxidant and anti-inflammatory support for our body. Let's see where we can find it in food, what are the benefits and the possible side effects.
Existen varios estudios publicados e investigaciones en curso sobre la quercetina y sus propiedades. En los últimos años, se recomienda cada vez más como un suplemento para promover la actividad antioxidante y antiinflamatoria del cuerpo y ayudar a contrarrestar la acción de los radicales libres y el envejecimiento celular. Este excepcional flavonoide parece actuar como un verdadero antienvejecimiento natural, contrarrestando el envejecimiento prematuro de la piel, las arrugas, las imperfecciones y la flacidez.
Quercetin helps reduce the damage of solar radiation on the skin, one of the first causes of the appearance of spots, marks, and wrinkles. Excessive exposure to the sun leads to a synthesis of oxygen reactions which form free radicals, substances that alter and damage the structure of the synthesis of collagen and elastin in the skin.
Quercetin contributes to protecting against the negative action of solar radiation and various other aging-related problems, including degenerative ones, for which scientific investigations are still taking place.
In addition to the recognized antioxidant properties of quercetin, there is the anti-inflammatory, antiplatelet and antithrombotic properties detected by some studies that describe quercetin as a valid support for the health of the cardiovascular system. It is still commonly used to assist the treatment of:
- symptoms of venous insufficiency (cramps, swelling),
- varicose veins,
- capillary fragility.
Quercitin's ability to support the protection of blood vessels and to help avoid edema and heaviness in the legs is recognized. This flavonoid is also valuable as a support to prevent urinary tract infections and prostate inflammation, which can affect men.
A very interesting factor inherent in the immune system is the potential of quercetin to reduce the symptoms of the main allergies, for example, that from pollen, since it seems that the substance can inhibit the phases that determine the release of histamine.
Quercetin is also finding more and more space as a nutraceutical adjuvant in anti-inflammatory drug therapies, helping to inhibit the production of prostaglandins and leukotrienes that have a pro-inflammatory action. It can be taken as support in the treatment of rheumatoid arthritis, psoriasis, systemic lupus erythematosus (chronic autoimmune diseases), Alzheimer's disease, arteriosclerosis, and insulin resistance syndrome.
Quercetin in food
Several foods commonly found on our table are rich in quercetin. This flavonoid is present in particularly high concentrations within:
- red fruits
- citrus fruits,
- red wine,
- green and black tea.
The doses of quercetin in food varies according to the cultivation method. The ideal is always to choose organic foods, to ensure an optimal amount of flavonoids.
Side effects and interactions
Quercetin has very few known side effects. Despite this, it is important to remember that it is not exempt from being able to determine the appearance of drug interactions to be taken into consideration. People with blood clotting diseases must pay particular attention due to the antiplatelet and antithrombotic activity of quercetin.
Patients who are taking antiplatelet drugs (such as Aspirinetta and CardioAspirin), anticoagulants for oral use (such as Coumadin and Sintrom), or who follow chemotherapy therapies should avoid using them. Its use is also not recommended for pregnant or breastfeeding women because, for now, there is no news on the possible effects on the fetus and baby.
Since quercetin has low bioavailability, it is very difficult to take an optimal amount to benefit only from diet. For this, supplements come into play, which typically has a recommended dose of about 200 mg/day.
- The effect of quercetin supplementation on selected markers of inflammation and oxidative stress, Gholamreza Askari, Reza Ghiasvand, Awat Feizi, Syed Mustafa Ghanadian, and Jahangir Karimian, J Res Med Sci. 2012 Jul; 17(7): 637-641.
- Overviews of Biological Importance of Quercetin: A Bioactive Flavonoid
Alexander Victor Anand David, Radhakrishnan Arulmoli, and Subramani Parasuraman, Pharmacogn Rev. 2016 Jul-Dec; 10(20): 84-89. doi: 10.4103/0973-7847.194044
- What are the benefits of quercetin? Medically reviewed by Alan Carter, Pharm.D. — Written by Beth Sissons on January 14, 2019, medicalnewstoday.com
- The Influence of Quercetin on Exercise Performance and Muscle Mitochondria, Jacob Schor, ND, FABNO, May 2010, www.naturalmedicinejournal.com
- What Is Quercetin? Benefits, Foods, Dosage, and Side Effects, Ryan Raman, MS, RD, June 27, 2019, www.healthline.com
- Quercetin - Penn State Hershey Medical Center - ADAM, http://pennstatehershey.adam.com
- Impact of quercetin on systemic levels of inflammation: a meta-analysis of randomised controlled human trials, Qiaowen OuORCID Icon, Zhifen ZhengORCID Icon, Yongyi ZhaoORCID Icon & Weiqun Lin, Pages 152-163 | Received 01 Feb 2019, Accepted 01 Jun 2019, Published online: 18 Jun 2019, https://doi.org/10.1080/09637486.2019.1627515
- A Review of Quercetin: Chemistry, Antioxidant Properties, and Bioavailability, Alexandra B. Bentz, Appalachian State University, 2009, Journal of young investigators, www.jyi.org