Research shows that anti-inflammatory foods containing quercetin can help help with a number of health problems, including heart disease, blood vessel problems, allergies, infections, chronic fatigue and symptoms related to autoimmune disorders like arthritis. It is a plant flavonol (from the flavonoid group of polyphenols). It is found in many fruits, vegetables, leaves, seeds, and grains. Quercetin inhibits a liver enzyme called UGT2B17 which breaks down hormones.
- Capers contain huge amounts of quercetin which is a powerful anti-inflammatory phytochemical compound.
- Olives are rich in quercetin. The health benefits of olives mainly come from the excellent micro-nutrient content: iron, calcium, fiber, copper, vitamin E, vitamin K, choline, sodium, phenolic compounds and omega-9. Olives are a rich source of antioxidants such as oleuropein, hydroxytyrosol, tyrosol and oleonalic acid.
- Japanese green tea is rich in quercetin.
- Onions are rich in quercetin.
- Other foods to note are: Dock plant, red leaf lettuce, watercress, cilantro, asparagus, okra, romaine lettuce, green peppers, kale, cranberry, apples, radish, red wine and cherries.
Chloroquine is in the news right now as a magic bullet in the treatment of Covid-19. It was first synthesised in 1934 at Bayer, and it became a major antimalarial drug after World War II. One danger of chloroquine is liver toxicity, but studies have shown that quercetin + chloroquine has a reduced liver threat.
Quercetin also had antiviral activity against HIV-luc/SARS, influenza A and Ebola. So it is thought that quercetin would be preventative to some degree against Covid-19.