Therapeutic efficacy of orally administered pollen for nonallergic diseases: An umbrella review.

Pollen has been used for centuries as a tonic and a multipurpose remedy in traditional medicine. The present umbrella review aims to qualitatively assess the therapeutic efficacy of orally administered pollen in the management of nonallergic diseases. MEDLINE via PubMed, Embase, Scopus, Web of Science, CINAHL, Cochrane Library, and Google Scholar were systematically searched for relevant systematic reviews and meta-analyses. Articles were independently screened and selected, then quality of evidence of included studies was evaluated with a dedicated NIH tool. Retrieved evidence was critically appraised and discussed. Two hundred four articles were found and, after selection process, five systematic reviews were included in the present work, including one with a meta-analysis. Evidence from these reviews supports the use of grass pollen extracts for symptomatic benign prostatic hyperplasia (BPH) and chronic prostatitis (CP). Additional preliminary evidence on the topic indicates the potential use of grass pollen extracts for vasomotor symptoms in women. Overall, results of the present review suggest that flower pollen extracts may be useful as a complementary remedy for the management of BPH, CP, and vasomotor symptoms. Evidence regarding bee pollen is too limited to draw any conclusion on its clinical efficacy. Further studies are needed.