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Paleodiet: bread, porridge and beer before farming

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Paleodiet : Bread, porridge and beer before agriculture

It was not until people started farming that they grind grain into flour and bake bread. Even hunters and gatherers produced porridge and beer on a large scale. by Andrew Curry The monuments of Göbekli Tepe are around 11,600 years old. Groups of hunters may once have met there and consumed plenty of grain dishes - and beer. Loading … © Ahmet Cigsar/Getty Images/iStock (excerpt)

On a clear day, the view extends from the ruins of Göbekli Tepe to the Syrian border 50 kilometers away. The archaeological site in southern Turkey, which is located at the highest point of a mountain range, is often referred to as the “oldest temple in the world”. The T-shaped columns and circular enclosures go back 11 & nbsp; 600 & nbsp; years. They are therefore older than the earliest clay pots in the Middle East.

The builders of the monument lived at a time when a significant moment in human history was approaching: the Neolithic Revolution. It was then that people gradually began to farm, raise crops and animals. But not so on the Göbekli Tepe. So far, there are no traces of domesticated grain at the site. Apparently the “temple-goers” had not yet started farming. Rather, they lived from hunting, as numerous animal bones show. Groups of hunters and gatherers from the wider area probably came together on Göbekli Tepe and celebrated lavish festivities with plenty of roasted meat. And perhaps such feasts gave the occasion to erect the impressive architecture.

This thesis has been around for a long time in archeology. Until a few years ago. Because the evidence has changed – thanks to researchers like Laura Dietrich from the German Archaeological Institute in Berlin. Over the past four years she has found out that the builders of Göbekli Tepe ate porridge and stew by the vat & nbsp; – and milled and processed the grain for it on an almost industrial scale. Accordingly, grains were on the menu much earlier than previously assumed & nbsp; – at a time when no one had domesticated grain.

Dietrich's work joins a growing number of research projects examining the role of cereals and other starchy foods in human nutritional history. To do this, the scientists use various methods. They examine tiny signs of use on tools or sequence the remnants of old DNA on clay pots. Some researchers even cook 12 & nbsp; 000 & nbsp; year old dishes experimentally using Stone Age methods. The archaeological guild looks even further into the past. It is quite possible that people ate starchy plants more than 100 & nbsp; 000 & nbsp; years ago.

Why the paleodiet never existed

The latest discoveries are shaking an old idea: that in the early days people lived primarily on meat. Nutritional trends such as the paleodiet, which advises avoiding grains and other starchy foods, has won this thesis many followers. But archaeologists are now finding the opposite: “We have enough evidence to show that we have overlooked an entire food category all along,” says Dorian Fuller, archaeobotanist at University College London.

Stone by stone Loading … © Hassan Yıldız (detail) Brick by Brick | The archaeologist Laura Dietrich documents rubbing stones and troughs in Göbekli Tepe's “rock garden”.

Laura Dietrich discovered the first indications of a not quite as meat-rich festival culture on Göbekli Tepe in the excavation's “rock garden”. This is what archaeologists call the area in which the stone finds are deposited. Dietrich documented rubbing stones made of basalt, troughs made of limestone and larger chunks of processed stone that the excavators repeatedly plucked from the field of ruins. The stone collection had grown steadily for a good two decades, says Dietrich. “But nobody has ever thought about the pieces.” When she began cataloging the stone finds in 2016, she was initially amazed at the sheer amount of material. The “garden” extended over an area the size of a soccer field. More than 10 & nbsp; 000 & nbsp; rubstones, almost 650 & nbsp; large stone plates and vessels & nbsp; – some of them large enough to hold 200 & nbsp; liters of liquid & nbsp; – were discovered during the excavations.

“No other settlement in the Middle East has so many rubstones, not even in the late Neolithic, when agriculture was already established,” says Dietrich. “We also have a whole range of stone vessels here – in all possible sizes. Why were there so many stone vessels? ”The researcher suspects: They were used to grind and grind grain to make porridge and brew beer. In fact, archaeologists have long assumed that the stone vats of Göbekli Tepe prove ritual beer consumption & nbsp; – however, according to the previous assumption, for rather occasional and rare moments of pleasure.

»Everyone who has already cooked something , know: Sometimes something burns «(Lucy Kubiak-Martens, archaeobotanist, BIAX Consult Biological Archeology & Environmental Reconstruction)

Eliciting their former purpose from the stones of Göbekli Tepe is tricky. Meat meals leave much clearer marks. Simply because the bones of slaughtered animals outlast time more often and better than grain or other vegetable foods. And because organic remains are so fragile, archaeobotany – the science of how humans once used plants – proves to be arduous and time-consuming work : The specialists usually come with buckets, sieves and fine nets to wash out the excavation earth. The heavy crumbs of earth and stone sink into the water, and tiny organic residues such as seeds, charred wood and burned food float on top. But most of what the archaeobotanists fish out are the remains of uncooked food: grass seeds, grains or grape seeds, which can at least be counted and determined. This shows which vegetation once prevailed in the vicinity of a site. If there are conspicuously large quantities of a species, it appears to have been a useful plant that humans may even have grown.

One of the earliest records of plant domestication are grains of einkorn. Specimens also came to light near Göbekli Tepe. They differ slightly from the wild form of wheat, both externally and genetically. The einkorn from Göbekli Tepe, on the other hand, resembles the original form. As a result, no one had grown any grain there or was still at the very beginning. However, experts also suspect that it took centuries for the shape of the grains to change through breeding.

Small and large kitchen disasters

What is much more difficult to detect are cooked vegetables or grains. However, archaeologists have found a largely neglected source to identify what was once dishes: charred leftovers. So what was left over if the stew sat on the fire too long, pieces of bread fell through the grate or a whole loaf burned in the oven. “Everyone who has cooked something knows: Sometimes something burns,” explains archaeobotanist Lucy Kubiak-Martens from BIAX Consult Biological Archeology & nbsp; & nbsp; & nbsp; Environmental Reconstruction in Zaandam, the Netherlands.

Remains of smaller and larger kitchen disasters are difficult to analyze and until a few years ago hardly found scientific fans. “It's just complicated material & nbsp; – fragile, ugly stuff,” says Andreas Heiss, archaeobotanist at the Austrian Academy of Sciences in Vienna. “Most researchers simply shy away from it.” In addition, ceramic shards to which burned food stuck were often cleaned or disposed of as “heavy pottery”. Charred food could sometimes be documented as probable food that could not be examined and then ended up in the depot or thrown away.

The way to change this is to go to the stove. In any case, this was the idea behind Soultana Valamoti, who works as an archaeobotanist at Aristotle University in Thessaloniki, Greece. It is no coincidence that Valamoti is a passionate cook. In the first years of her research career, she dragged buckets and sieves from excavation site to excavation site all over Greece, searching museum depots for old plant remains. Valamoti was convinced that burned leftovers represented an untapped and fertile field of archeology. If only you could find a way to identify them analytically.

The fast food of the Bronze Age Loading … © Nature from Valamoti, S.M. et al .: Deciphering ancient recipes ’from charred cereal fragments: An integrated methodological approach using experimental, ethnographic and archaeological evidence. Journal of Archaeological Science 128, 2021, fig. 18 a + c; Curry, A .: How ancient people fell in love with bread, beer and other carbs. Nature 594, 2021; German version: Spectrum of Science (excerpt)

That is why Valamoti converted her laboratory into an experimental kitchen more than two decades ago. She grated wheat, cooked bulgur from it, and burned it on the stove to simulate a millennia-old kitchen accident. In fact, their cremated remains resembled 4000 year old specimens from a site in northern Greece. This type of grain preparation has its origin at least in the Bronze Age.

Let the bread, porridge and bulgur burn in a controlled manner

Valamoti continued to experiment for years. Since 2016, thanks to a grant from the European Research Council, she has been able to create a reference collection with more than 300 crispy charred samples from ancient times and experimentally produced equivalents. She mixed dough, baked bread, cooked porridge, bulgur and a traditional Greek dish called trachana made from old wheat and barley & nbsp; – and let all the dishes burn in the oven under controlled conditions.

»It was the fast food of the past « (Soultana Valamoti, archaeobotanist, Aristotle University of Thessaloniki)

She then looked at the pieces under the microscope, magnified 750 to 1000 times, in order to identify typical changes in the cell structure that occur during cooking, baking and cooking. When magnified, the grains differ depending on whether they were cooked or fresh, whether they were ground or left whole, whether they were dried or soaked. When baking bread, for example, special bubbles form, while cooking, on the other hand, the starch in the grain gels before it charring, says Valamoti. “We can see all of this in the scanning electron microscope.”

Through her experiments and comparisons with prehistoric specimens, Valamoti has found out more than would be possible with the mere determination of plant species. She has reconstructed the cooking methods and dishes of Bronze Age Greece. Apparently, people there have been eating bulgur for at least 4000 years, according to a study from 2021. Barley or wheat was boiled and the grain allowed to dry to later soak if necessary. So “you could process the harvest in large quantities and take advantage of the hot sun,” says Valamoti. “People lived on their grain that way all year round. It was the fast food of the past «, says the archaeobotanist.

The vegetable diet is in the genes

Other researchers are also looking for traces of ancient mishaps around the hearth fire. Remnants of burnt food “provide us with direct evidence of food,” says Amaia Arranz-Otaegui. The archeobotanist at the Paris Museum of Natural History is convinced that the research field of food archeology would be “like a revolution”. The food would “offer a completely new source of information.” Before that, there was hardly any evidence that early humans also ate plants. Although “we always suspected that the early hominins and the early homo sapiens lived on starch, we had no evidence”, emphasizes Lucy Kubiak-Martens.

Genetic data support the fact that people have been consuming starchy food for a long time. Compared to other primates, the genome of Homo sapiens contains more copies of the gene that produces enzymes for digesting starch. “Humans have up to 20 copies, chimpanzees only two,” says Cynthia Larbey, archaeobotanist at the University of Cambridge, who was involved in the 2016 study. This genetic adaptation in the human lineage shaped the diet of our ancestors – and that of today's humans. “Starchy food seems to have offered a selection advantage for Homo sapiens,” explains Larbey.

During field work Loading … © Joe Roe (detail) Working in the fields | Amaia Arranz-Otaegui (right) examines grain that grows near the Jordanian site of Shubayqa & nbsp; 1. The archaeobotanist and her team found that people were baking bread about 14,000 years ago – long before grain was domesticated.

In search of solid archaeological evidence, the researcher looked at around 120 & nbsp; 000 & nbsp; year old hearths in South Africa. She picked peanut-sized remains of charred plants from the findings and analyzed the pieces. And indeed: using the scanning electron microscope, she identified cell tissue from starchy plants. Larbey had found the earliest evidence that people cooked dishes containing starch. “From 65 & nbsp; 000 & nbsp; to 120 & nbsp; 000 & nbsp; years ago they prepared roots and tubers,” says Larbey. The evidence covers a remarkably long period, especially when compared to the animal remains from the same site. “In the course of time, hunting techniques and strategies changed, but you kept cooking and eating plants.”

The early humans apparently had a balanced diet: They used starchy plants as a source of calories when few wild animals roamed around or were difficult to kill. “And if you ventured into new ecosystems and were able to find carbohydrates there, then you had secured an important staple food”, adds Larbey.

Vegetarian meals in the tartar of the Neanderthals

Plant-based nutrition is likely to have played an important role as early as the Neanderthals. In 2011, the paleoanthropologist Amanda Henry from the University of Leiden examined the plaque of those early humans who lived around 40 & nbsp; 000 to 46 & nbsp; 000 & nbsp; years ago in what is now Iran and Belgium. The tartar contained microfossils from plants. Apparently both the Neanderthals in Europe and those in the Near East had cooked and ate starchy foods such as tubers, grains or dates. “Plants are omnipresent in our environment,” says Henry. “So it's no surprise that we use them.”

“The old-fashioned idea that hunters and gatherers didn't eat starch is nonsense” (Dorian Fuller, archaeobotanist, University College London)

In May 2021, paleogeneticists working with Christina Warinner at Harvard University reported that they had succeeded in extracting bacterial DNA from the dental plaque of Neanderthals. Among them was a sample from the tooth of an individual who had lived 100 & nbsp; 000 & nbsp; years ago in what is now Serbia. Some of the identified types of bacteria are able to break down starch into sugar. Presumably, the Neanderthals had already adapted to a plant-based diet. A similar microbiome was found in the tartar of early anatomically modern humans. Apparently they also ate starchy plants.

These findings contradict the widespread opinion that our ancestors spent their time around the campfire and only ate mammoth steaks & nbsp; – keyword paleodiet. Its supporters demand that we do without grain or potatoes because our hunter-gatherer ancestors did not feed on them, they were not evolutionarily prepared for them. But it is now clear that since the Paleolithic, various human forms, as soon as they were able to control the fire, also prepared and ate carbohydrate-containing foods. “The old-fashioned idea that hunters and gatherers didn't eat starch is nonsense,” says archaeobotanist Dorian Fuller.

Who were the cooks?

In order to find out how people once worked at the hearth fire, archaeologists want to research the cooks themselves. Scientists have long been concerned with household and everyday life in bygone cultures. “We're trying to find sources of information that tell us more about these people who don't appear in written sources,” explains archaeologist Sarah Graff from Arizona State University in Tempe.

So far, researchers have come across plant remains, they mostly classified the finds as “eco-facts” – as natural, more or less accidentally created objects. Seeds, pollen and burned wood were mainly used to reconstruct the vegetation of a region. That has now changed. Leftovers provide information about activities that require manual skills, certain skills and deliberate action. “Finding a prepared food must be understood primarily as an artifact and secondly as a plant species to be determined,” says Fuller. »Heated, fermented, soaked & nbsp; – the activity of preparing food can be compared to pottery.«

Because archaeologists are working more and more closely with researchers from neighboring disciplines, more and more astonishing parallels are opening up across times and cultures. In Baden-Württemberg and Switzerland, for example, excavators discovered unusually shaped remains of fire at Neolithic sites more than 5000 years old. At first glance it seemed as if the contents of a large clay pot had been heated until the liquid had evaporated and the organic matter burned itself in. At first, the excavators suspected that the charred crusts came from storage vessels for grain that were destroyed in a fire. In the scanning electron microscope, however, it was noticed that the cell walls of individual grains were unusually thin. Something else seemed to have happened here.

Heiss and Valamoti compared the leftovers with those from ancient Egyptian breweries, which belonged to around the same time. Their conclusion: The thin cell walls were created by germination or malting, an important phase in the brewing process. The early farmers in the Alpine region brewed beer. “We came to a completely different result than initially assumed,” says Heiss.

Telltale bubbles in & nbsp; bread

The art of bread-making seems to go back even further than the craft of brewing. Arranz-Otaegui was doing research at a 14 & nbsp; 500 & nbsp; year old site in Jordan when she was picking burned bits of “possible food” from the hearths of former hunter-gatherer cultures. She placed the black remains in a scanning electron microscope and showed images of them to the archaeobotanist Lara González Carretero from the Museum of London Archeology. González Carretero works at the Neolithic settlement Çatalhöyük in Turkey, where she is looking for traces of bread bakers. The two researchers were astonished when they saw the charred fragments from Jordan enlarged: They discovered the very same bubbles that are typical for bread.

Most archaeologists assume that bread was only made with the Neolithic Revolution came onto the human diet. Grain farming and agriculture established themselves 5000 & nbsp; years after breadcrumbs fell into the hearth of hunters and gatherers. It seems that the early bakers in Jordan processed wild wheat.

The find could explain why the Neolithic Revolution occurred in the first place, why it took place around the world, independently of one another, multiple times and at different times. Before agriculture existed, bread may have been a luxury product. It took a lot of time and labor to gather enough wild grain. Perhaps the effort provided the reason to accelerate “earning a living”. Arranz-Otaegui is convinced that the need for bread & nbsp; – at least in the Middle East & nbsp; – led to the domestication of wheat. Because they were looking for a way to always be able to bake enough bread. “What we found out in Jordan also changes our picture of the big picture,” explains Arranz-Otaegui. “One of the most important questions in archeology is: what made the transition to agriculture? And now we see that hunters and gatherers used grain. «

Ancient stove Loading … © Alexis Pantos (detail) Ancient stove | Researchers discovered burnt remains of bread at this fireplace at the Shubayqa & nbsp; 1 site in Jordan. The charred pastry is older than the earliest evidence of agriculture.

The next item on the archaeobotanists' menu is the prehistoric salad buffet – also a neglected area of ​​former diets. Researchers are currently working on methods to detect traces of raw vegetables. Uncooked greens are even less evident in the archaeological findings than heated seeds and grains. Lucy Kubiak-Martens calls it the missing link in research on prehistoric eating habits. “There is no way of using charred leftovers to prove that humans once ate green lettuce.” But there is at least one genre that is probably informative: “You would be surprised if you knew how many green vegetables can be found in human coprolites,” says Kubiak-Martens. We are talking about fossilized or preserved faeces. The Dutch researcher received a grant in 2019 to study 6,300 & nbsp; year old coprolites that have survived in wetland areas in the Netherlands. The scientist hopes that the excretions will reveal what was served up by early farmers in Europe.

Old meals cooked anew

Some researchers go out of their way to uncover prehistoric eating habits. As in the case of Göbekli Tepe. Hardly any organic remains came to light there – and thus far too little to reconstruct the vegetable diet of the time. For this reason Laura Dietrich approached the problem differently. Instead of cooking the dishes from back then, she took the traditional kitchen utensils and reproduced them.

In her experimental kitchen in Berlin, Dietrich demonstrates her process, which not only takes a lot of time, but also requires a lot of physical effort. She made a handy grating stone about the size of a bread roll out of black basalt. Dietrich photographs the piece from 144 different angles. Then she grinds flour. For eight hours she grinds four kilograms of einkorn with the basalt. Then Dietrich photographs the stone, also known as the runner, again. She loads the images into a software program that uses them to create two 3-D models. Their conclusion: The grinding of fine flour, which is good for baking bread, leaves different marks on the stone surface than if the grain is only roughly ground, for example to cook porridge or brew beer.

The beer from Göbekli Tepe & nbsp; – »a bit bitter, but drinkable when you're thirsty and live in the Neolithic Age« (Laura Dietrich, archaeologist, German Archaeological Institute Berlin)

Now that the archaeologist has thousands of rubstones in her hand, she can often feel what they were used for as soon as she touches them. “I touch the stones to feel the signs of wear,” she says. “The fingers can feel changes on the nano-level.” Dietrich compared the signs of use on her copies with those on runners in the rock garden of Göbekli Tepe. She found out that the specimens there were rarely used to grind fine bread flour. Much more often, people only roughly ground the grain, as Dietrich describes in a study in 2020. Just enough to break open the hard outer shell, the bran. This made it easier to cook the grain into porridge or ferment into beer.

The researcher wanted to test her hypothesis. She commissioned a stonemason to recreate a stone tub from Göbekli Tepe with a capacity of 30 liters. Together with her team, Dietrich cooked porridge with it in 2019 by placing hot stones in the container. In the vessel she also brewed Neolithic beer from hand-crushed germinated grain, i.e. from malt. The result was “a bit bitter, but drinkable”, says Dietrich, “if you are thirsty and live in the Neolithic”.

Lots of grain in Göbekli & nbsp; Tepe

What was going on in Göbekli Tepe 12 & nbsp; 000 & nbsp; years ago? Apparently something that archaeologists actually suspect much later. The rubbing stones and troughs show that the builders of the site were very familiar with the wild grain and knew how to prepare it. Basically, they were early farmers even though they did not have domesticated crops. “These are the best rubbing stones ever & nbsp; – and I've seen a lot of rubbing stones,” says Dietrich. »The people in Göbekli Tepe knew what they were doing and how to handle grain. They were past the phase of experimentation. «

Dietrich's experiments have changed the interpretation of Göbekli Tepe. Previously, most archaeologists assumed that numerous hunters would meet on the hill at festival times, eat grilled antelope and drink lukewarm beer by the barrel. “Nobody considered the possibility that plant-based food was consumed here on a large scale,” says Dietrich.

In a study from 2020, she explains that the “barbecue-and-beer” – Scenario for Göbekli Tepe does not apply at all. The many tools for grain processing show that grain was a staple food there even before the transition to arable farming & nbsp; – and not only in fermented form as an occasional luxury item.

© Springer Nature Limited

© Springer Nature Limited
Nature, 10.1038/d41586-021- 01681-w, 2021

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