Quercetin is a bioflavonoid (or flavonoid), which is a type pigment found in almost all herbs, fruits, and vegetables. Black tea, broccoli, onions, red apples, and red wine are good sources of this nutrient. Quercetin supplements are also available in concentrated powders and tablet or capsule form. It is often packaged with bromelain (an enzyme found in pineapple), another substance that has been found useful for treatment of allergies and inflammation, which is thought to increase the absorption of quercetin.

Anti-inflammatory and antioxidant

Quercetin is one of the most powerful and effective herbal anti-inflammatory, and antioxidant supplements on the market today. It has been shown to help prevent the development of a variety of conditions related to inflammation and free-radical damage, including arthritis, allergies, macular degeneration, heart disease, gout, and various forms of cancer.

Cancer

• Quercetin blocks the flow of nutrients and oxygen to cancerous cells, it also binds to estrogen-receptor sites in place of estrogen so that breast cancers that flourish on oestrogen are no longer stimulated to grow.
• Laboratory studies have shown that quercetin from citrus fruits can reduce the growth rate of breast cancer cells by as much as 50 percent.
• Quercetin has been shown in animal and test tube studies to inhibit the growth of colon, prostate, breast, and lung cancer cells.

Allergies

• Histamine causes inflammation and swelling, and is responsible for the stuffy nose, itchy eyes, sneezing, and other annoying symptoms associated with allergies. Quercetin blocks the secretion of histamine thereby helping to treat allergies.

Inflammation - Arthritis & Prostrate

Studies show that Quercetin can inhibit the type of inflammation that causes swollen joints in arthritis sufferers as well as inflammation of the prostate gland (chronic prostatitis).

• People with rheumatoid arthritis who switched to a diet loaded with lots of bioflavonoid-rich foods have reported significant improvement in their symptoms.
• Just 500 milligrams of quercetin twice each day was found to improve pelvic pain symptoms in men with prostatitis.
• Preliminary laboratory studies have also shown that quercetin may inhibit the growth of prostate cancer cells.

Skin

• Quercetin increases the production of both collagen and fibronectin, two substances necessary to keep the joints and skin healthy.
• Quercetin is an active ingredient in more and more cosmetic products that claim to help diminish signs of aging.
• Studies have also shown that quercetin helps repair damage to nerve tissues in skin wounds.

Heart disease

• Quercetin helps reduce the risk of heart disease by preventing the accumulation of macrophages in the arteries, thereby helping to prevent clogged arteries, or atherosclerosis.
• Quercetin improves circulation by strengthening capillaries throughout the body, and helps to prevent and treat diseases caused by poor blood supply to the eyes, such as cataracts, diabetic retinopathy, and macular degeneration.