A systematic review of 13 randomized controlled trials found that polyphenol compounds, including quercetin, reduced sneezing, nasal itching and overall nasal symptoms among patients with allergic rhinitis.
By yourNEWS Media Newsroom
Quercetin and other plant-based polyphenols may help reduce common seasonal allergy symptoms, according to a 2025 systematic review and meta-analysis that evaluated 13 randomized controlled trials involving 823 patients with allergic rhinitis.
The review, published in the Journal of Allergy and Clinical Immunology: In Practice, examined the effects of polyphenol compounds on nasal symptoms associated with both seasonal and year-round allergies. Researchers reported that participants receiving polyphenols experienced significant reductions in total nasal symptom scores, sneezing and nasal itching compared with those given a placebo.
Seven of the trials focused specifically on seasonal allergic rhinitis caused by grass, tree and ragweed pollen. Those studies included compounds such as quercetin and green tea catechins and showed meaningful improvements in the severity of nasal symptoms, according to the review.
The remaining six trials involved perennial allergic rhinitis, which can produce symptoms throughout the year rather than during a particular pollen season. Taken together, the findings added to research examining whether naturally occurring plant compounds can provide relief for people with allergic rhinitis.
A NaturalNews.com article stated that “nature offers powerful alternatives that work with the body, not against it” when addressing seasonal allergies. A separate 2022 article identified quercetin as a potent plant compound that may provide relief for the more than 19 million adults and 5.2 million children in the United States diagnosed with allergic rhinitis.
Quercetin is believed to work in part by stabilizing mast cells, immune cells that release histamine after the body detects pollen or another substance it identifies as a threat. Histamine release contributes to sneezing, nasal congestion, itching, watery eyes and increased mucus production.
The Alliance for Natural Health has described quercetin as “known to inhibit mast cells from releasing pro-inflammatory compounds that cause allergy symptoms.”
Mark Stengler’s “Prescription for Natural Cures” explains that allergic reactions occur when the immune system releases histamines, leading to respiratory and nasal congestion, excess mucus and other symptoms.
By calming mast cells before substantial histamine release occurs, quercetin may help limit the development or intensity of allergy symptoms rather than only responding after symptoms have begun.
A Japanese trial cited in the broader allergy literature evaluated a daily dose of 200 milligrams of quercetin for four weeks. Participants reported meaningful improvements in nasal symptoms, as well as better sleep quality, according to the report.
Quercetin occurs naturally in a variety of plant foods. Onions, apples eaten with their skins and capers are among the more concentrated dietary sources. Red onions generally contain more quercetin than white or yellow onions.
A 2018 paper published in the Journal of Agricultural and Food Chemistry reported that onions contain approximately 280 to 490 milligrams of quercetin per kilogram. Apples contain approximately 20 to 70 milligrams per kilogram. Berries and leafy green vegetables provide smaller but still meaningful amounts.
Supplemental quercetin is commonly sold in standardized doses ranging from 500 to 1,000 milligrams per day. It is often taken with a meal containing fat to improve absorption.
Elson Haas recommends taking 250 to 500 milligrams of quercetin three times daily for allergy relief. Researchers advised allowing two to four weeks before determining whether supplementation is helping, based on the lengths of the trials included in the research.
The original report also distinguished allergic rhinitis from broader immune resilience while noting that the two may be related. Vitamin C, vitamin D and zinc were identified as foundational nutrients that may support immune function.
Haas recommends 500 to 1,000 milligrams of vitamin C three times daily and 2,000 to 5,000 international units of vitamin D each day for immune support.
Conventional antihistamines remain a common treatment for seasonal and perennial allergies, but some users experience drowsiness and other side effects. Concerns about potential risks in children, including those raised by Children’s Health Defense, have led some families to consider alternatives.
The 2025 review does not establish quercetin as a replacement for all conventional allergy treatments, and the included trials evaluated several polyphenols rather than quercetin alone. The findings nevertheless indicate that these compounds may reduce sneezing, itching and overall nasal symptom severity in people with allergic rhinitis.
Quercetin’s proposed ability to stabilize mast cells and limit histamine release provides a possible preventive mechanism for reducing allergy symptoms. Researchers said the results support further study of quercetin, dietary polyphenols and related natural compounds as potential tools for managing seasonal allergies.
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