Quercetin is a unique bioflavonoid that has been extensively studied by researchers over the past 30 years.  Bioflavonoids -- first discovered by Nobel Prize Laureate Albert Szent-Gyorgyi in the 1930's -- occur as pigments in plants, where they usually are found in close association with vitamin C.  Together, bioflavonoids and vitamin C provide antioxidant protection, helping plants withstand harsh variations in wind, rainfall, temperature, and sunlight.  Bioflavonoids also can be important to our optimal health -- but they cannot be manufactured by our bodies.  

Quercetin is no stranger to the human diet: for example, onions may contain up to 6% quercetin (dry weight).  As a food supplement, quercetin is hypoallergenic, containing no citrus, wheat, corn, or other common allergens. 

Histamine and Leukotriene Inhibition: Helping People to Enjoy the Natural World

Quercetin has a strong affinity for mast cells, the body's main storage unit for histamines.  Like many other bioflavonoids, quercetin has the ability to stabilize cell membranes, preventing histamines from spilling out of mast cells into the bloodstream and surrounding tissues.  Also, quercetin helps inhibit the action of two enzymes -- phospholipase A2 and lipoxygenase -- which act on arachidonic acid (a key fatty acid constituent of many cell membranes) to create leukotrienes. 

By inhibiting the release of histamines and leukotrienes into the bloodstream, quercetin can leave people free to enjoy the natural world.  

Activated for Absorption

Quercetin's main disadvantage is that it is barely soluble in water, and therefore difficult for the body to absorb.  Without biochemical help, its beneficial properties may be of very limited use to our bodies. There are lots of quercetin products on the market, but they won't do much good if the quercetin is not activated for use by the body.  

Bromelain, an enzyme derived from pineapple is known to increase the body's ability to absorb various substances.  Bromelain also is known to have many of the same histamine- and leukotriene-inhibiting properties of quercetin.  So by combining quercetin and bromelain they enhance each others' performance. 

Studies suggest that Vitamin C has a synergistic relationship with quercetin.  Vitamin C improves quercetin's use by the body.  Since the acidic form of vitamin C (ascorbic acid) can create mild stomach irritation, and since quercetin is best taken on an empty stomach to maximize absorption, a pH-buffered form of vitamin C such as magnesium ascorbate is appropriate to combine in a quercetin formula.