Neanderthals ate plants as food and knew about their healing properties, according to a University of York report.

Neanderthals, members of a species closely related to modern humans, were believed to be meat-eaters. But now, an international team of scientists has found that they ate plants too. The discovery was made while analysing five Neanderthals' teeth obtained from the El Sidrón in north Spain.

During the study, scientists used thermal desorption and pyrolysis-gas chromatography-mass spectrometry to identify both polymeric organic components in the dental calculus (calcified dental plaque) from the Neanderthals' teeth.

Researchers found several chemicals such as methyl esters, phenols, and polynuclear aromatic hydrocarbons, in the dental calculus. Analysis of the chemicals revealed that they ate plants; they also roasted some plants and consumed them.

"Using mass spectrometry, we were able to identify the building blocks of carbohydrates in the calculus of two adults, one individual in particular having apparently eaten several different carbohydrate-rich foods. Combined with the microscopic analysis it also demonstrates how dental calculus can provide a rich source of information," said Professor Matthew Collins, who heads the BioArCh research facility at York, in a statement.

Researchers claim that varied use of plants found in their teeth clearly shows that the Neanderthals had knowledge of their natural surroundings which included the ability to select and use certain plants for their nutritional value and for self-medication.

"The varied use of plants we identified suggests that the Neanderthal occupants of El Sidrón had a sophisticated knowledge of their natural surroundings which included the ability to select and use certain plants for their nutritional value and for self-medication. While meat was clearly important, our research points to an even more complex diet than has previously been supposed," said Karen Hardy, researcher at the Universitat Autònoma de Barcelona (UAB), in a statement

Antonio Rosas, of the Museum of Natural History in Madrid, said El Sidrón had enabled scientists to banish many of the preconceptions about Neanderthals. He cited previous studies to point out that Neanderthals looked after the sick, buried their dead and decorated their bodies. "Now another dimension has been added relating to their diet and self-medication," he said, in a statement.