Evidence from dirty teeth: Ancient Peruvians ate well

December 1, 2008

Starch grains preserved on human teeth reveal that ancient Peruvians ate a variety of cultivated crops including squash, beans, peanuts and the fruit of cultivated pacay trees.

This finding by Dolores Piperno, staff scientist at the Smithsonian Tropical Research Institute and the National Museum of Natural History, and Tom Dillehay, professor of archaeology at Vanderbilt University, sets the date of the earliest human consumption of beans and pacay back by more than 2,000 years and indicates that New World people were committed farmers earlier than previously thought.

In northern Peru’s Ñanchoc Valley, Dillehay and colleagues recovered human teeth from hearths and floors of permanent, roundhouse structures. Human bone, plant remains and charcoal closely associated with the teeth are approximately 6,000 to 8,000 years old according to carbon- dating techniques.

Piperno examined 39 human teeth, probably from six to eight individuals. “Some teeth were dirtier than others. We found starch grains on most of the teeth. About a third of the teeth contained large numbers of starch grains,” Piperno said.

To identify the starch grains, Piperno compared the particles in tooth scrapings with her modern reference collection of starch grains from more than 500 economically important plants. “We found starch from a variety of cultivated plants: squash, Phaseolus beans—either limas or common beans, possibly, but not certainly the former, pacay and peanuts,” said Piperno. “Parts of plants that often are not evident in archeological remains, such as the flesh of squash fruits and the nuts of peanuts, do produce identifiable starch grains.”

Starch from squash found on the teeth affirms that early people were eating the plants and not simply using them for nonfood purposes, such as for making containers or net floats. Whether or not some of the earliest cultivated plants, such as squashes, were grown as dietary items has been a long-debated question among students of early agriculture.

Evidence that foods had been cooked was also visible on some of the starch grains. “We boiled beans in the lab to see what cooked starch grains looked like—and recognized these gelatinized or heat-damaged grains in the samples from the teeth,” said Piperno. Starch from raw and roasted peanuts looks similar, probably because it is protected within the hull.

Starch grains from four of the crops were found consistently through time indicating that beans, peanuts, squash and pacay were important food sources then, as they are today. “Starch analysis of teeth, which, unlike other archaeobotanical techniques, provides direct evidence of plant consumption, should greatly improve our ability to address other important questions in human dietary change relating to even earlier time periods,” said Piperno.

The results of this study appear online in Proceedings of the National Academy of Sciences, the week of Dec. 1-5, 2008.

Provided by Smithsonian Tropical Research Institute

Explore further: Dental plaque reveals key plant in prehistoric Easter Island diet

Related Stories

Study finds Neanderthals ate their veggies

December 27, 2010

A US study on Monday found that Neanderthals, prehistoric cousins of humans, ate grains and vegetables as well as meat, cooking them over fire in the same way homo sapiens did.

Recommended for you

48-million-year-old horse-like fetus discovered in Germany

October 7, 2015

A 48 million year-old horse-like equoid fetus has been discovered at the Messel pit near Frankfurt, Germany according to a study published October 7, 2015 in the open-access journal PLOS ONE by Jens Lorenz Franzen from Senckenberg ...

Chimpanzees shed light on origins of human walking

October 6, 2015

A research team led by Stony Brook University investigating human and chimpanzee locomotion have uncovered unexpected similarities in the way the two species use their upper body during two-legged walking. The results, reported ...

How much for that Nobel prize in the window?

October 3, 2015

No need to make peace in the Middle East, resolve one of science's great mysteries or pen a masterpiece: the easiest way to get yourself a Nobel prize may be to buy one.

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.