Scientists gleaned an insight into the menu enjoyed by Neanderthals by scraping away the calcified plaque stuck on their teeth and examining the DNA within it.

In a paper published in the journal Nature this week, researchers analyzed samples from 48,000-year-old Neanderthal remains in Spain and 36,000-year-old remains from Belgium. The tartar contained food particles, as well as microbes from the mouth and the gastrointestinal and respiratory tracts.

Scientists from Australia's University of Adelaide and the UK's University of Liverpool found there was a big difference between the two. At the Spy Cave site in Belgium, which at the time had been a hilly and grassy environment, the diet was meat-based. It included woolly rhinoceros and wild sheep, as well as wild mushrooms.

Meat apparently absent

Dental tartar examined from the El Cidrón Cave site in Spain, then situated in a densely forested area, showed a mainly vegetarian regimen. Again, it included wild mushrooms, as well as pine nuts, but there was no sign of meat being eaten. Rather less appealingly, the Spanish Neanderthals would supplement their diets with moss and tree bark.  

Because Neanderthals had no access to professional dental cleaning services, the plaque provides a lifelong indicator of what the cavemen were eating.

"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," said lead author Laura Weyrich, from the  University of Adelaide's Australian Centre for Ancient DNA.

Hervé Bocherens, a paleobiologist at the University of Tübingen, Germany, told Nature that the fact no evidence of meat was found in the mouths of the Spanish Neanderthals did not mean they were vegetarian. DNA databases that cover extinct species that Neanderthals might have eaten simply do not exist, said Bocherens.

Using nature's pharmacy?

Among the more surprising finds was one from an individual who had suffered a dental abscess and appeared to have been eating poplar tree bark that contained salicylic acid - the active ingredient of aspirin. There was also evidence of natural antibiotic mold (penicillin) being present.

"Apparently, Neanderthals possessed a good knowledge of medicinal plants and their various anti-inflammatory and pain-relieving properties, and seem to be self-medicating," said Professor Alan Cooper, director of ACAD. "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."