▷ Quercetin: Applications, Consumption, Dosage and Toxicity

Major in Nutrition with specialization in Health and Disease.

Published: 09/30/2014 - Updated: 01/07/2018

Quercetin is a hydrosoluble flavonoid (natural pigment) found in certain fruits and vegetables. Apart from having coloring properties, it has the following properties as well:

Antioxidant: it has high percentages of antioxidants which, among other things, helps prevent premature cell and tissue wear due to the presence of free radicals.
Anti-inflammatory: relaxing activity for musculature.
Anti-carcinogen
Analgesics
Vasodilators
Antibacterial
Anti-inflammatory
Antispasmodic
Anti-flu
Liver protector
Antiviral
Anti-diabetic
Anti-asthmatic

Contents

Health applications for quercetin:
Modes of consumption:
Quercetin is found primarily in the following foods:

Health applications for quercetin:

Circulatory system: takes part in relaxing the blood vessels, prevents varicose veins and heart problems, as well as cerebral embolism.
Virus: fights viruses and acts efficiently against the herpes simple virus. Prevents the appearance of canker sores or lesions in the mouth, and helps fight viral illnesses.
Allergies and asthma: quercetin acts against mastocytes to prevent them from releasing histamine which causes allergic reaction symptoms. This is why it is recommended in natural treatments against these conditions. It is one natural help for fighting food and respiratory (hay fever) allergies.
Prevents aging and deterioration of the organs and systems, including the brain. This flavonoid contains powerful antioxidants. Consuming foods rich in quercetin is an excellent way to keep yourself young, and to keep your skin healthy.
Infections: helps cases of interstitial cystitis, boils, acne, dermatitis, etc.
Prevents cancer: quercitin could be able to cure liver cancer and to prevent the development of other tumors or myomas.
Prostatitis: helps eliminate symptoms like pain, and helps reduce inflammation in the prostate.
Protects the kidneys from some medication’s toxicity, and from frequent medication use.
Prevents LDL cholesterol from oxidizing, thereby preventing it from sticking to artery walls.
Quercetin has been used as a therapy for treating cardiovascular problems, cataracts due to diabetes, inflammation, gastrointestinal ulcers and hepatitis.

NOTE: Several studies have related quercetin to a reduced risk of coronary heart disease, embolisms, cancers and other conditions. However, there is still not enough solid evidence that completely supports these testimonies.

Modes of consumption:

One appropriate way of providing the body with this powerful antioxidant is to include 5 or more pieces of fruit and vegetables in your daily diet. Quercetin can also be taken as a supplement or capsule (which can be found in natural food stores), although if using this method, its best to consult a specialist.

Quercetin is found primarily in the following foods:

Onion (especially red or purple onions), green tea, apples, cherries, pears, spinach, cabbage, Brussel sprouts, oatmeal, mangoes, garlic, broccoli, cauliflower, beans, Ginkgo biloba, St. John’s Wort, blueberries, redcurrant, black tea and red wine.

You should keep in mind that eating raw foods increases the percentage of quercetin in foods. One good recommendation is to eat fruits and vegetables raw, either in juices or salads, changing the vegetables daily.

Quercetin dosage:

An approximate quercetin dosage for adults is between 600 and 1200 mg, spread out in 3 doses a day. You must use caution if consuming it in pills or capsules, as quercetin overdose could cause gastric irritation, nausea and vomiting. It is always good to check the dosage on the back of the bottle, or consult a specialist.

Quercitin toxicity:

Pregnant or nursing women should not take capsuled quercetin supplements. Intravenous use could cause nausea, sweats, and respiratory problems. You should also not take quercetin supplements if you are taking any antidepressant medication.