Quercetin, a potent plant compound found in many fruits and vegetables, has been shown to offer relief from allergies. This is good news for the more than 19 million adults and 5.2 million children in the U.S. diagnosed with allergic rhinitis in the past 12 months.
Also called hay fever and seasonal allergies, allergic rhinitis causes several troublesome symptoms – such as congestion, itching, sneezing, coughing, headache and watery eyes. Oftentimes, antihistamines are used to treat allergic rhinitis and other kinds of allergies. However, these drugs come with unwanted side effects such as drowsiness, dizziness and rapid heart rate.
A May 2016 study published in Molecules found that quercetin can help address the immune system’s response to allergic triggers. According to the study authors from the Czech Republic and Slovakia, the plant compound blocks the production and release of histamine, the chemical responsible for hay fever and other allergic reactions. Histamine is produced by mast cells and certain white blood cells called basophils.
“Quercetin inhibits the production and release of histamine and other allergic and inflammatory substances, possibly by stabilizing cell membranes of mast cells,” they wrote. “It is a reason why quercetin is suitable for the treatment of mast cell-derived allergic inflammatory diseases such as asthma, sinusitis and rheumatoid arthritis.” (Related: Quercetin alleviates allergies and enhances immune system function.)
The researchers also cited a prior trial on rats given peanut infusion to trigger anaphylactic reactions. One group of rats were given quercetin daily for four weeks, while the second control group received none. The histamine levels of rats in both groups were then compared, with those in the experimental group showing lower levels than the other group.
“Quercetin is, therefore, a potent suppressor of the ongoing immunoglobulin E (IgE) responses against peanut proteins, and can be introduced as an alternative medicine like a defender against IgE-mediated food allergies,” wrote the authors of the May 2016 study.
What foods are rich in quercetin?
The Czech and Slovakian authors also mentioned several fruits and vegetables that are packed with quercetin.
First, they cited onions as a quercetin-rich food. “The amount of quercetin in onions varies with bulb color and type, being distributed mostly in the outer skins and rings. Thus, the highest loss of quercetin happens when onions are peeled.”
Apples were also cited as a quercetin-rich fruit, with the compound present entirely in the peels. “Due to the presence of more antioxidants such as quercetin in the apple peel than in the flesh, the apple peels may be considered to have higher antioxidant capacity and also bioactivity.”
Lori Alton, staff writer for NaturalHealth365, also attested to the quercetin content of apple peels. She added that red apples have higher quercetin content than green apples. “Don’t even think of peeling that apple; most of its quercetin is found in the skin,” Alton advised.
Different kinds of berries also contain quercetin, according to the researchers. These include strawberries, blueberries, raspberries, cranberries, blackcurrants and Saskatoon berries – the latter containing “exceptionally high” amounts of the plant compounds.
The researchers noted that black tea and oolong tea – which both undergo fermentation – contain the highest amount of quercetins. Oolong tea contains between 50 and 52 percent quercetin, while black tea’s quercetin content ranges between 54 and 71 percent. Other kinds of tea such as green tea, raw pu-erh tea and white tea also contain the potent plant compound.
“As a growing body of research shows, quercetin is emerging as a potent natural antioxidant that can help to combat allergies,” Alton concluded.
Watch Dr. Sam Bailey discuss the benefits of quercetin below.
This video is from the SurvivalTV channel on Brighteon.com.