Available online 5 July 2025

What is already known about this topic? Polyphenolic compounds (e.g., apple polyphenol, catechins, or quercetin) may inhibit hypersensitivity reactions and alleviate allergic symptoms; however, the clinical evidence remains inconsistent.

What does this article add to our knowledge? This systematic review and meta-analysis suggests that polyphenolic compounds may alleviate nasal symptoms in allergic rhinitis, especially seasonal type. However, these findings require cautious interpretation due to substantial heterogeneity and a low certainty of evidence.

How does this study impact current management guidelines? Polyphenolic compounds may serve as a complementary option, requiring cautious interpretation and a shared decision-making approach. Current evidence is insufficient for a strong guideline recommendation, and more rigorous trials are needed to confirm their role.

Polyphenolic compounds (e.g., catechins or quercetin) may reduce hypersensitivity and allergic symptoms, but clinical evidence remains inconsistent.

To evaluate the therapeutic potential of polyphenolic compounds for managing allergic rhinitis (AR).

A systematic review and meta-analysis of randomized controlled trials assessed the effects of polyphenolic compounds on AR symptoms and quality of life (QoL).

Thirteen RCTs (823 participants) were included: seven enrolling patients with seasonal AR, and six with perennial AR. In seasonal AR, polyphenolic compounds significantly reduced total nasal symptom scores (standardized mean difference [SMD] = 0.75, p = 0.0001; I2 = 52.8%), sneezing (SMD = 0.58, p = 0.0042; I2 = 45.6%), and nasal itching (SMD = 0.54, p = 0.011; I2 = 41.7%). In perennial AR, total nasal symptom scores improved, while individual symptoms were inconclusive. The combined analysis of seasonal and perennial AR, along with a sensitivity analysis excluding two outlier trials, yielded a more conservative and robust estimate, showing reductions in total nasal symptom scores (SMD = 0.73, p < 0.0001; I2 = 38.1%), nasal obstruction (SMD = 0.50; p = 0.0003; I2 = 36.4%), and sneezing (SMD = 0.57; p < 0.0001; I2 = 25.7%). Overall certainty of evidence for key nasal symptom outcomes was low to very low due to inconsistency and risk of bias. Effects on QoL were not significant.

Polyphenolic compounds may serve as a complementary option for alleviating nasal symptoms in patients with AR, but findings should be interpreted cautiously. Future large-scale, rigorous RCTs are needed.

© 2025 Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology