Spring. Each year it heralds the long awaited transition from the cold of winter, easing us into the warmth and spoils of summer. Despite all the benefits warmer weather tends to bring, for millions of people, Spring also means allergies and misery for about 20% of the Australian population.
Whether the culprit be dust mites, pollens, grasses, pollutants, or foods, these allergens trigger the production of antibodies known as immunoglobulin E (IgE). These IgE antibodies then attach to specific immune cells known as mast cells and basophils causing them to release copious amounts of histamine, pro-inflammatory prostaglandins and cytokines.[1,2] This results in the well-known symptoms of allergy such as runny, itchy nose; watery eyes; irritated throat; skin rash and asthma.
Quercetin is a naturally occurring compound belonging to a class of substances known as bioflavonoids, which are widely recognised for their potent antioxidant, anti-inflammatory and anti-allergic benefits.
Quercetin has a particularly strong affinity for mast cells and basophils, and once attached, it stabilises the cell membrane to ultimately prevent cell degranulation and histamine release.[3,4] Additionally, it decreases inflammation via inhibition of neutrophil lysosomal enzyme secretion and leukotriene production.[3,5]
In one study, quercetin was shown to significantly inhibit antigen-stimulated histamine release from mast cells obtained from the nasal mucosa of individuals with perennial allergic rhinitis. Quercetin’s effect was almost twice that of sodium cromoglycate at the same concentration.
The recommended dose of quercetin for symptomatic relief of allergic rhinitis ranges from 250-600mg, taken three times daily, 5-10 minutes before meals. Furthermore, when taken in combination with bromelain, absorption and bioavailability of quercetin is vastly improved. Bromelain, derived from pineapple stems, is an enzyme well known for enhancing absorption of many other compounds as well as having anti-allergy properties itself.
- Turner P, Kemp A. Allergic rhinitis in children. J Paediatr Child Health 2012 Apr;48(4):302-10 [Abstract]
- Pawankar R, Bunnag C, Chen Y, et al. Allergic rhinitis and its impact on asthma update (ARIA 2008)--western and Asian-Pacific perspective. Asian Pac J Allergy Immunol 2009 Dec;27(4):237-43. [Full Text]
- Thornhill SM, Kelly AM. Natural treatment of perennial allergic rhinitis. Altern Med Rev 2000;5(5):448-54. [Full Text]
- Helms S, Miller A. Natural treatment of chronic rhinosinusitis. Altern Med Rev 2006;11(3):196-207. [Full Text]
- Park H, Lee S, Son H, et al. Flavonoids inhibit histamine release and expression of proinflammatory cytokines in mast cells. Arch Pharm Res 2008;31(10):1303-11. [Abstract]
- Secor E, Carson W, Cloutier M, et al. Bromelain exerts anti-inflammatory effects in an ovalbumin-induced murine model of allergic airway disease. Cell Immunol 2005;237(1):68-75. [Full Text]