Dental News - DNA from dental calculus shows Neanderthal used natural analgesics

Dental Tribune International

Fri. 5. May 2017

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ADELAIDE, Australia/LIVERPOOL, UK: Ancient DNA in the calcified dental plaque of Neanderthals—the nearest extinct relative to humans—has provided new insights into their behaviour, diet and evolutionary history. An international team of researchers has analysed 42,000- to 50,000-year-old dental plaque DNA samples from four Neanderthals found at cave sites in Belgium and Spain. The findings revealed the complexity of Neanderthal behaviour, including knowledge of plant-based medication and dietary differences.

According to the researchers, DNA preserved in the dental plaque of Neanderthals is a notable source of information about the behaviour and health of ancient hominin specimens. From analysing the dental plaque DNA samples, the researchers learnt that the Neanderthals from the cave sites of Spy in Belgium consumed woolly rhinoceros, European wild sheep and wild mushrooms. In contrast, those from El Sidrón cave in Spain appeared to have a vegetarian diet, including moss, mushrooms, pine nuts and tree bark, but no evidence of meat was found. These findings demonstrate that these two groups had very different diets.

“Dental plaque traps microorganisms that lived in the mouth and pathogens found in the respiratory and gastrointestinal tract, as well as bits of food stuck in the teeth—preserving the DNA for thousands of years,” said lead author Dr Laura Weyrich, Australian Research Council Discovery Early Career Research Fellow at the Australian Centre for Ancient DNA (ACAD) of the University of Adelaide.

She added, “One of the most surprising finds, however, was in a Neanderthal from El Sidrón, who suffered from a dental abscess visible on the jawbone. The plaque showed that he also had an intestinal parasite that causes acute diarrhoea, so clearly he was quite sick. He was eating poplar, which contains the pain killer salicylic acid (the active ingredient of aspirin), and we could also detect a natural antibiotic mould (Penicillium) not seen in the other specimens.”

Furthermore, dietary differences were associated with a general shift in the oral microbiota, suggesting that meat consumption contributed to substantial variation in this regard. “Not only can we now access direct evidence of what our ancestors were eating, but differences in diet and lifestyle also seem to be reflected in the commensal bacteria that lived in the mouths of both Neanderthals and modern humans,” said co-author Prof. Keith Dobney, from the University of Liverpool. “Major changes in what we eat have, however, significantly altered the balance of these microbial communities over thousands of years, which in turn continue to have fundamental consequences for our own health and well-being.”

The study, titled “Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus”, was published on 20 April in the Nature journal. It was conducted by ACAD in collaboration with the University of Liverpool in the UK.