By Pat Anson, Editor

Neanderthals may be a lot smarter than we give them credit for. Especially when it comes to finding pain relief.

Ancient DNA extracted from the dental plaque of Neanderthals has revealed new insights into their behavior and diet, including their use of plant-based medicine to treat pain and illness.

An international team of researchers compared dental plaque from the jawbones of four Neanderthals found at ancient cave sites in Belgium (Spy Cave) and Spain (El Sidrón Cave). The four samples range from 42,000 to around 50,000 years old and are the oldest dental plaque ever to be genetically analyzed.

“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,” says Dr. Laura Weyrich, a research fellow at the University of Adelaide’s Australian Centre for Ancient DNA (ACAD), who was lead author of the groundbreaking study reported in the journal Nature.

“Genetic analysis of that DNA ‘locked-up’ in plaque, represents a unique window into Neanderthal lifestyle – revealing new details of what they ate, what their health was like and how the environment impacted their behavior.”

The researchers found that Neanderthals from Spy Cave were mostly meat eaters who consumed wooly rhinoceros and wild sheep, and supplemented their diet with wild mushrooms.

“Those from El Sidrón Cave on the other hand showed no evidence for meat consumption, but appeared instead to have a largely vegetarian diet, comprising pine nuts, moss, mushrooms and tree bark – showing quite different lifestyles between the two groups,” said professor Alan Cooper, Director of ACAD.

The analysis of one Neanderthal found at El Sidrón revealed another surprise. He probably had pain from a dental abscess on his jawbone, and also had signs of an intestinal parasite that causes acute diarrhea.

“Clearly he was quite sick. He was eating poplar, which contains the pain killer salicylic acid, and we could also detect a natural antibiotic mold not seen in the other specimens,” said Cooper. “Apparently, Neanderthals possessed a good knowledge of medicinal plants and their various anti-inflammatory and pain-relieving properties, and seem to be self-medicating.”

Salicylic acid is the active ingredient in aspirin; while certain types of mold – such as Penicillium – help the body fight off infections.

“The use of antibiotics would be very surprising, as this is more than 40,000 years before we developed penicillin. Certainly our findings contrast markedly with the rather simplistic view of our ancient relatives in popular imagination,” says Cooper.

The researchers also found that Neanderthals and modern humans shared several disease-causing microbes, including the bacteria that cause dental cavities and gum disease.

Types of bacteria were closely associated with the amount of meat in the diet, with the Spanish Neanderthals grouping with ancient human ancestors in Africa. In contrast, the Belgian Neanderthal bacteria were similar to early hunter gatherers, and quite close to modern humans and early farmers.

“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 Professor Keith Dobney of 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. This extraordinary window on the past is providing us with new ways to explore and understand our evolutionary history through the microorganisms that lived in us and with us.”