Neanderthal Dental Plaque Reveals Plant-Based Diet, Drug Use and Kissing Habits

Ancient teeth can say a lot about a person - or in this case, a Neanderthal. In a new paper published in the journal Nature, scientists uncovered more details about our cousins through their dental "records": a mostly plant-based diet, self-medication with painkillers and antibiotics, and a potential propensity for kissing humans.

According to a report from New Scientist, the scientists analyzed Neanderthal's teeth, focusing on plaque that has hardened over the millenia. Much of these hardened plaque, also known as dental calculus, have remained on the teeth even through thousands of years. Three individual Neanderthals were the focus of the study: a pair of 48,000-year-old specimens from the El Sidrón site in northern Spain and a 39,000-year-old one from the Spy site in Belgium.

Breaking down the Neanderthal diet

Despite Belgium and Spain being only 1,000 kilometers apart, their diets differed greatly. The solo Neanderthal from Spy had a meat-rich diet consisting of woolly rhinoceros, sheep and mushrooms, with no plants. On the other hand, the two El Sidrón representatives ate moss, bark and mushrooms, with no meat.

Researchers suggested that the opportunities provided by the environment play a huge role. Few animals for hunting may have forced the Neanderthals in El Sidrón to adapt a plant-rich diet.

Amanda Henry from the Leiden University in the Netherlands explained that the DNA findings shouldn't be taken as the complete picture, pointing out that most of the DNA is from oral bacteria and not from the food of the Neanderthals. She added, "To suggest they are recovering the entirety of the diet here is a bit premature."

Furthermore Henry's previous works have talked about the Spy Neanderthals eating roots and tubers along with meat. Luca Fiorenza of the Monash University in Australia added that the specimen from Belgium likely ate a substantial amount of plants or mushrooms as well, because of the dangers of sticking to a purely animal protein diet.

Self-medicating, kissing Neanderthals

Meanwhile, one of the El Sidrón specimen, a teenage boy, was found with DNA sequences of poplar plants, known for having the natural pain killer salicylic acid. There was also DNA from Penicillium fungus in the dental calculus.

These medications were likely for the teenager's dental abscess or the newly-detected diarrhoea-causing gut parasite in his system.

While the presence of the fungus could be attributed to it growing on a plant the Neanderthal ate, it's worth noting that its DNA wasn't found in the dental calculus of the other El Sidrón specimen who's presumably healthy.

Despite his dental abscess and possible diarrhoea, the teenage Neanderthal seemed to have gotten some action in his time. An ancient genome of oral bacteria Methanobrevibacter oralis was found in his dental calculus as well. The bacteria, found both in the Neanderthal and modern humans, could be explained by the well-known interbreeding between the two species.

One of the authors Laura Weyrich from the University of Adelaide explained that it's possible that humans and Neanderthals kissed while having sex 110,000 years ago, so that they both ended up with similar M. oralis bacteria.

While the idea is thought-provoking, Adam Siepel at the Cold Spring Harbor Laboratory in New York said that there are other possible explanations like drinking from the same water sources or salvaging food from each other.