Herbs for allergic rhinitis? Original paper

In this meta-analysis of randomized controlled trials, herbal supplements improved nasal symptoms, compared to a placebo, in participants with allergic rhinitis. However, the low quality of the studies limits our confidence in the results.

The effect of herbal medicines in the context of allergic rhinitis.

The outcomes were overall allergic rhinitis symptoms and nasal symptoms, including total nasal symptoms and specific nasal symptoms such as sneezing, runny nose, nasal congestion, and nasal itchiness, all of which were assessed using questionnaires.

A total of 1,769 participants (average ages of 6 to 46) with allergic rhinitis.

A meta-analysis of 27 randomized controlled trials was performed.

The most commonly studied herb was Petasites hybridus (also known as butterbur; 5 studies), followed by stinging nettle and cinnamon (2 studies each). In the rest of the studies, a formulation containing multiple herbs was taken. In 83% of studies, the intervention was administered orally, and it was given intranasally in the other studies. Herbal medicine was either the sole intervention or added on to usual treatment.

In 20 studies, herbal medicine was compared to a placebo; in the other studies, the control group received usual treatment, which typically was an antihistamine. The studies were at least 1 week long, and over half of them were at least 28 days long.

There were 4 to 7 studies in each analysis. Compared to the placebo group, scores for total nasal symptoms (small effect size), nasal congestion (large effect size), and sneezing (large effect size) were better in the herbal medicine group at the end of the intervention. Also, an improvement in overall allergic rhinitis symptoms was 43% more likely in the herbal medicine group.

In studies that compared herbal medicine to an antihistamine, the nasal congestion score was better (small effect size) in the herbal medicine group at the end of the study.

Only 1 of the studies had a low overall risk of bias, and the rest had at least some concerns. Also, the certainty of evidence was very low to low. Different herbal medicines were used in each study, so it’s unclear which is the most effective for improving allergic rhinitis symptoms. For these reasons, we have little confidence in the results.