Quercetin is a natural antihistamine found widely in nature that provides symptomatic relief of hayfever and seasonal upper respiratory tract allergies. Antihistamines in general compete with histamine at receptor sites around the body, so help to protect you from the ill-effects of large amounts of histamine.
Quercetin, the king of flavonoids
- Quercetin is a naturally occurring flavonoid or bioflavonoid, a water-soluble plant pigment that give plants their vibrant colours. Quercetin is found in many fruits, vegetables, leaves and grains including apples, red onions, red grapes, citrus fruit, tomato, broccoli, raspberries, blueberries, blackberries, green tea, capers and parsley.
- Flavonoids possess potent anti-inflammatory and antioxidant activity. Other flavonoids, including rutin and hesperidin, have a similar action to that of quercetin, although quercetin is the most active of the flavonoids, providing greater bioavailability for a better therapeutic effect.
- Allergies produce abnormal immune responses to objects that are typically harmless to most of us. When you're allergic to something, your immune system mistakenly believes that this substance is harmful to your body, so it establishes a defence mechanism to protect you.
- Your immune system generates large quantities of a defence molecule called immunoglobulin E (IgE), an antibody that attaches itself to the allergen. Each IgE antibody is specific to a particular allergen, so if you're allergic to grass pollen, you would have large numbers of specific IgE antibodies for grass pollen, but no IgE antibodies for any other types of pollen.
- After your first exposure to an allergen, the IgE antibodies produced attach themselves to immune system cells called mast cells. These mast cells become primed and ready to be activated when you next encounter that allergen. At the next exposure to this allergen, the IgE antibodies attached to the primed mast cells, signal the release of large amounts of histamine and other chemicals that cause inflammation and irritation, responsible for your allergy symptoms.
- Quercetin's natural antihistamine activity helps to reduce the strength of an allergic reaction, reducing the inflammation and irritation associated with allergy symptoms. Excessive histamine release is largely responsible for the symptoms of hayfever and seasonal upper respiratory tract allergies including runny nose, sneezing and itchy, watery eyes, so antihistamines help to reduce these symptoms.
- Quercetin provides significant anti-inflammatory activity by blocking a number of different inflammatory pathways in the initial stages of an allergic response, helping to decrease the level of inflammation associated with allergic reactions.
- The antioxidant activity of quercetin helps to mop up free radicals that cause damage in your body and preserves the action of vitamin C, another natural antihistamine. Free radicals have the ability to activate inflammatory pathways in your body.
- Quercetin is generally well tolerated and is suitable for children aged 6 and over. The recommended dosage for hayfever and seasonal upper respiratory tract allergies ranges from 250-600mg, in divided doses, throughout the day. For more see Herbs of Gold Quercetin Complex.