Quercetin Plus


Quercetin bioflavonoid compound for maximum anti-oxidant protection


Quercetin is widely distributed in the plant kingdom and has been shown in experimental studies to have numerous effects on the body. It is found in many often-consumed foods, including apple, onion, tea, berries, and brassica vegetables, as well as many seeds, nuts, flowers, barks, and leaves. It is also found in medicinal botanicals and is often a major component of the medicinal activity of the plant. Quercetin appears to have many beneficial effects on human health, including cardiovascular protection, anti-cancer activity, anti-ulcer effects, anti-allergy activity, cataract prevention, antiviral activity, and anti-inflammatory effects. Quercetin is extensively employed in the Protocols section of the Complete Blood Type Encyclopedia.


Quercetin.  Quercetin’s anti-inflammatory activity appears to be due to its antioxidant and inhibitory effects on inflammation-producing enzymes (cyclooxygenase, lipoxygenase) and the subsequent inhibition of inflammatory mediators, including leukotrienes and prostaglandins. Inhibition of histamine release by mast cells and basophils also contributes to quercetin’s anti-inflammatory activity.

Quercetin’s mast-cell-stabilizing effects make it a clear choice for use in preventing histamine release in allergy cases. Quercetin’s cardiovascular effects center on its antioxidant and anti-inflammatory activity. In one study, the risk of heart disease mortality decreased significantly as flavonoid intake increased. Interestingly, the flavonoid-containing foods most commonly eaten in this study contain a high amount of quercetin (tea, onions, apples).

Quercetin is indicated in any inflammatory condition, as it inhibits the formation of the inflammatory prostaglandins and leukotrienes, as well as histamine release. Animal studies have shown quercetin to be protective of gastric ulceration and an interesting aspect of quercetin’s anti-ulcer effect is that it has been shown to inhibit growth of Helicobacter pylori in a dose- dependent manner. Quercetin may help treat or even prevent prostate cancer by blocking male hormones that encourage the growth of prostate cancer cells, according to preliminary laboratory research at the Mayo Clinic. In another study, men with an inflamed prostate (prostatitis) reported reduced urinary symptoms when they took quercetin. Quercetin has been investigated in a number of animal models and human cancer cell lines and has been found to have antiproliferative effects. It may also increase the effectiveness of chemotherapeutic agents. More clinically-oriented research needs to be done in this area to discover effective dosage ranges and protocols.

Quercetin’s aldose reductase-inhibiting properties may make it a useful addition to diabetic nutritional supplementation, to prevent cataract and neurovascular complications.

Bromelain.  Bromelain's anti-inflammatory activity appears to be due to a variety of physiological actions. Evidence indicates that bromelain's action is in part a result of inhibiting the generation of bradykinin at the inflammatory site via depletion of the plasma kallikrein system, as well as limiting the formation of fibrin by reduction of clotting cascade intermediates. Bromelain has also been shown to stimulate the conversion of plasminogen to plasmin, resulting in increased fibrinolysis. (22) Bromelain was added to this formula to help with the absorption of quercetin and for its anti-inflammatory activity. Research from F.B. Giller from his 1962 study in the American Journal of Pharmacology indicated that bromelain affects the level of absorption in rabbits of a few different antibiotics including penicillin.


TABLE 1: Key agents in Quercetin Plus.


Allergies, asthma, and hives:  Quercetin may inhibit histamine release from basophils (a type of white blood cell) and mast cells (large cells in connective tissue).

Cancer:  Quercetin may be beneficial in the treatment of skin cancer, and may have anti-tumor effects in other cancers, such as ovarian cancer.

Canker sores:  Quercetin may reduce the frequency of mouth sores and produce mild symptomatic relief.

Diabetes mellitus:  Quercetin may help prevent cataracts, retinal disorders, nerve diseases, and other complications of diabetes. Flavonoids, including quercetin, also promote insulin secretion, increase vitamin C levels, protect blood vessels, prevent easy bruising, and support the immune system—all of which are beneficial to individuals with diabetes.

Heart disease:  Individuals with very low intakes of flavonoids are at higher risk for heart disease.

Infection:  Quercetin may control the spread of certain viruses within the body.

Rheumatoid arthritis:  Quercetin may help reduce tissue destruction.


1 capsule, twice daily on an empty stomach. An oral dose of 300-600 mg two times per day is typically used in clinical practice.


This product was introduced by NAP in 2002 after first being specifically designed for use in the D’Adamo Clinic.


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  22. North American Pharmcal TRM 2018 Bromelain.

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