Neanderthals may have utilized birch tar—a thick, sticky substance long recognized as a prehistoric adhesive for hafting stone tools—as an ancient form of medicine to combat bacterial infections and protect wounds, according to a study published in PLOS One.
University Researchers Recreate Pleistocene Extraction Techniques
A collaborative team of researchers from the University of Cologne, the University of Oxford, the University of Liège, and Cape Breton University investigated whether the adhesive possessed secondary applications. Archaeologists have frequently uncovered traces of birch tar attached to ancient stone tools across various European sites. For decades, these discoveries led researchers to believe that Neanderthals primarily used the material as glue. The substance helped early humans attach stone blades and points securely to wooden handles.
The research team sought to test whether this material served broader purposes in prehistoric life. To do this, they recreated production methods consistent with the Pleistocene era using tree species available during that time.
Investigators bypassed modern industrial processes entirely. Instead, they relied on two distinct reconstruction techniques.
- Placing birch bark inside a sealed underground pit and heating it with little or no oxygen to trigger dry distillation.
- Burning birch bark near a solid surface, such as a stone, so tar vapors condensed against the cooler area, leaving behind a harvestable residue.
Dry distillation breaks down the material and releases substances that can be collected as tar. Both extraction methods produced viable sticky residues.
Laboratory Tests Reveal Inhibition of Staphylococcus Aureus
The team subjected their experimentally produced samples to bacteriological testing. Every single batch of birch tar inhibited the growth of Staphylococcus aureus. Often abbreviated as S. aureus, this bacterium is a primary driver of common wound infections in modern clinical settings. Certain modern strains exhibit multi-drug resistance against conventional pharmaceuticals.
Crucially, the antibacterial efficacy appeared consistently across all extraction variations. The method of production did not alter the bacteria-inhibiting capability of the resulting substance.
“The findings suggest that antimicrobial properties played a role as far back as the time of the early Neanderthals and could have been used in a targeted manner,” stated Tjaark Siemssen of the University of Cologne and Oxford University, who led the current study. The results appeared in the journal PLOS One under the title “Antibacterial properties of experimentally produced birch tar and its medicinal affordances in the Pleistocene.”
Evidence from traditional societies globally shows that birch tar has been used for medicinal purposes as well as other applications. Combined with existing archaeological indicators pointing toward plant use and early medical care among Neanderthals, the chemical testing raises an intriguing question about how prehistoric humans interacted with their immediate biochemical environment.
Implications for Modern Antibiotic Resistance Research
The discovery arrives amid a global health concern surrounding antimicrobial resistance. As conventional pharmaceutical treatments lose efficacy against mutating pathogens, clinical researchers are casting a wider net for alternative compounds.
Laboratory inhibition does not guarantee safety or clinical effectiveness when applied directly to active human wounds. Further research would be needed to evaluate any practical medical deployment.
“Our findings show that it might be worthwhile to examine targeted antibiotics from ethnographic contexts—or, as in this case, from prehistoric contexts—in greater depth,” concluded Siemssen.
