Propolis, also called bee glue, is an aromatic reddish substance collected by honeybees from tree buds and bark, consisting of a mixture of tree resins, balsams, and waxes which are altered by the bees’ own secretions, esp. saliva and beeswax, and used by them to seal cracks in the hive and varnish the cells of the comb. (Thank you to the Oxford English Dictionary for this definition).
For centuries, healing properties have been attributed to propolis, and it is often touted as an herbal remedy or supplement. However, even a quick scan of the literature (such as the articles found on sciencedirect.com) strongly suggests that most of the evidence for its effectiveness is anecdotal. On a hopeful note, in vitro studies have supported claims for the anti-microbial effects of propolis, although actual clinical studies are nearly nonexistent (1). Part of the issue is that the chemical composition of propolis is very complex and can vary widely and depends largely on the local ecology, especially the plants from which the bees are collecting the resins (2).
In Petra Ahnert’s wonderful book Beehive Alchemy, of the fifty or so recipes involving bee products, only three include propolis (salve, toothpaste and throat lozenges). So it appears (for now, at least) that propolis is far more useful to the bees that it is to us.
And in my opinion, that’s really okay.
Featured image: Propolis found at the edge of a beehive. Photo courtesy of beeinformed.org.
(1) Red Propolis: Phenolics, Polyphenolics, and Applications to Microbiological Health and Disease, (Irlan A. Freires, … Bruno Bueno-Silva, in Polyphenols: Prevention and Treatment of Human Disease (Second Edition), 2018)
(2) A worldwide yearly survey of new data in adverse drug reactions and interactions N.H. Choulis, in Side Effects of Drugs Annual, 2012 (entry on Propolis)