Neanderthals had knowledge of healing plants

Karen Hardy (a dalt) i grup de grànuls de midó incrustats als càlculs dentals (a sota)

An international team of researchers, led by the Universitat Autònoma de Barcelona and the University of York, has obtained the first molecular evidence that Neanderthals not only ate a range of plant foods, but also understood its nutritional and medicinal qualities. Directed by Karen Hardy, ICREA researcher and lecturer at UAB, the study analysed the dental calculus (calcified dental plaque) of five individuals found in the cave of El Sidrón, in Asturias, and found the first evidence of the ingestion of yarrow and camomile.

18/07/2012

Until recently Neanderthals, who disappeared between 30,000 and 24,000 years ago, were thought to be predominantly meat-eaters. However, evidence of a varied diet is growing as more sophisticated analyses are undertaken.

In a recent study, researchers from Spain, the UK and Australia combined pyrolysis gas-chromatography-mass spectrometry with morphological analysis of plant microfossils to identify material trapped in dental calculus from five Neanderthals from the north Spanish site of El Sidrón and discovered the first molecular evidence for medicinal plants being used by a Neanderthal individual: yarrow and camomile. The results of the study, published in Naturwissenschaften – The Science of Nature this week, represent a new step in acquiring more in-depth knowledge about this species.

Lead author Karen Hardy, researcher at ICREA and lecturer at UAB, as well as Honorary Research Associate at the University of York, said: “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.”

Researchers combined mass spectrometry techniques and thermal desertion with morphological analysis of plant microfossils. The researchers said the starch granules and carbohydrate markers in the samples, plus evidence for plant compounds such as azulenes and coumarins, as well as possible evidence for nuts, grasses and even green vegetables, argue for a broader use of ingested plants than is often suggested by stable isotope analysis.

Antonio Rosas, of the Museum of Natural History in Madrid – CSIC (Spanish National Research Council), highlighted: “El Sidrón has allowed us to banish many of the preconceptions we had of Neanderthals. Thanks to previous studies, we know that they looked after the sick, buried their dead and decorated their bodies. Now another dimension has been added relating to their diet.”

Bitter-Tasting Plants

Studies conducted in 2009 by the excavation team at El Sidrón helped to identify the Neanderthal gene related to the perception of bitter taste. The study carried out this year has confirmed that at least one of the individuals analysed had eaten bitter-tasting plants, specifically yarrow and camomile. Dr Stephen Buckley, from the BioArCh research facility at University of York, said: “The evidence indicating this individual was eating bitter-tasting plants such as yarrow and camomile with little nutritional value is surprising. We know that Neanderthals would find these plants bitter, so it is likely these plants must have been selected for reasons other than taste.”

The study also found several organic components. The evidence of carbohydrates is confirmed by grounded and cooked starch granules observed microscopically and stemming from carbohydrate-rich plants. Smoked samples were also found, possibly from cooked or smoked food in the form of a range of chemical markers including methyl esters, phenols, and polynuclear aromatic hydrocarbons, as well as bitumen from bituminous slates.

Professor Matthew Collins, director of BioArCh, explained: “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.”

Professor Les Copeland from the Faculty of Agriculture and Environment, University of Sydney, Australia, said: “Our research confirms the varied and selective use of plants by Neanderthals.”

The study also provides evidence that the starch granules reported from El Sidrón represent the oldest granules ever to be confirmed using a biochemical test,

while ancient bacteria found embedded in the calculus offers the potential for future studies in oral health.

El Sidrón Cave
The archaeological cave site of El Sidrón, located in the Asturias region of northern Spain, contains the best collection of Neanderthal remains found in the Iberian Peninsula and one of the most important active sites in the world. Discovered in 1994, it contains some 2,000 skeletal remains of at least 13 individuals dating back some 47,300 to 50,600 years.

Fieldwork at El Sidrón, conducted by researchers from the University of Oviedo, is funded by the Department of Culture, Principality of Asturias. The dental calculus samples used in this study were provided by the laboratory leading the study of the remains discovered in El Sidrón.

Reference article: Hardy K et al. (2012). ‘Neanderthal medics? Evidence for food, cooking and medicinal plants entrapped in dental calculus’. Naturwissenschaften-The Science of Natureon Wednesday, 18 July. DOI 10.1007/s00114-012-0942-0

Images: Above: Karen Hardy. Below: starch granules trapped in the dental calculus.