Ancient leftovers show the real Paleo diet was a veggie feast

Today’s Paleo diet cookbooks might be missing a few pages. Archaeological excavations at a Stone Age site in Israel have revealed the first direct evidence of the sort of plants that our distant human ancestors ate with their meat and fish. Their tastes were more adventurous than we might expect, with roasted acorns and sedges both on the menu.

Archaeologists tend to emphasise the role of meat in ancient human diets, largely because the butchered bones of wild animals are so likely to be preserved at dig sites. Edible plants may have been overlooked simply because their remains don’t survive so well.

The Gesher Benot Ya’aqov site in northern Israel provides some of our first direct evidence of what plants early humans ate. The site was occupied 780,000 years ago, probably by Homo erectus or a very closely related species. Deep in history, waterlogging helped preserve evidence of its inhabitants’ diets – plants as well as meat.

Yoel Melamed and Naama Goren-Inbar at Bar-Ilan University in Ramat Gan, Israel, and their colleagues have compiled data on the diversity and abundance of plant remains during periods when there is evidence of human activity. They also looked at the plant remains from time frames when there is no evidence humans were present. By comparing the two sets of data, they could get a reasonable idea of which plants humans were deliberately gathering from their surroundings.

It turns out the ancient humans had extraordinarily broad tastes. They collected no fewer than 55 different kind of plant – harvesting their nuts, fruits, seeds and underground stems or eating them as vegetables (see “The real Paleo diet”, below).

“The modern human diet is clearly restricted when compared to the [early] hominin diet or even to the early farmers’ diet,” says Goren-Inbar.

Such broad tastes were probably essential, she says – they gave early humans a good chance of finding palatable food all year round. “It gives one a substantial element of security when particular sources become rare or absent.”

The work is a wonderful new resource, says Peter Ungar at the University of Arkansas in Fayetteville. “Any new data we can get concerning hominin palaeoecology during this very important period of human evolution is more than welcome.”

We know from previous work at Gesher Benot Ya’aqov that the early humans were adventurous in the way they ate animals as well: Goren-Inbar has found evidence for the consumption of elephant brain. So did early humans prefer to temper their meat-eating with a certain amount of veg, and if so, how much?

“There probably was no single balance between meat and plant,” says Ungar. “Human evolution is a work in progress, and diets likely varied along a continuum in both time and space.”

However, Amanda Henry at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, thinks that early human diets may have tipped towards being plant-rich. “We need plant-derived nutrients to survive – vitamin C and fibre, for example,” she says. “Hominins were probably predominantly vegetarians.”

Despite the diverse array of plants collected at Gesher Benot Ya’aqov, it’s very unlikely the people who lived there could have remained healthy as strict vegetarians, says Henry. “But only a very little amount of animal protein and fat is needed to supplement a predominantly plant-based diet.”

Either way, the team now suggest that a wide variety of plants would have been a major feature of what early human ate way before the dawn of agriculture. The site of Gesher Benot Ya’aqov also preserves some of the earliest evidence for controlled fire use, and tools would have enabled the hominins to process foods before cooking them.

Their knowledge of the environment allowed them to exploit plants seasonally – potentially allowing them to inhabit the same location year round.

Source: newscientist.com