How long have humans eaten wheat

During fermentation, bacteria break down milk sugars including lactase, turning them into acids and easing digestion for those with lactose intolerance.

Gone with those sugars, however, is a good chunk of the food's caloric content. A recent genetic study found that adult lactose tolerance was less common in Roman Britain than today, meaning its evolution has continued throughout Europe's recorded history.

These days, many humans have access to plentiful alternative foods as well as lactose-free milk or lactase pills that help them digest regular dairy. In other words, we can circumvent some impacts of natural selection. That means traits like lactose tolerance might not have the same direct impacts on survival or reproduction that they once did—at least in some parts of the world.

Yet trouble digesting gluten— the main protein found in wheat — is another relatively recent snag in human evolution. Humans didn't start storing and eating grains regularly until around 20, years ago, and wheat domestication didn't begin in earnest until about 10, years ago. Since wheat and rye became a staple of human diets, however, we've have had a relatively high frequency of celiac disease. The answer lies in our immune response.

A system of genes known as the human leukocyte antigens take part in the fight against disease, and frequently produce new variations to battle ever-changing infections. Unfortunately, for individuals with celiac disease, this system mistakes the human digestive system for a disease and attacks the lining of the gut. Yet despite the obvious drawbacks of celiac disease, ongoing evolution doesn't seem to be making it less frequent.

The genetic variants behind celiac disease seem to be just as common now as they've been since humans began eating wheat. Unintended trade-offs are common in evolution. Eating the same domesticated grain every day gave early farmers cavities and periodontal disease rarely found in hunter-gatherers, says Larsen.

When farmers began domesticating animals, those cattle, sheep, and goats became sources of milk and meat but also of parasites and new infectious diseases. Farmers suffered from iron deficiency and developmental delays, and they shrank in stature. Despite boosting population numbers, the lifestyle and diet of farmers were clearly not as healthy as the lifestyle and diet of hunter-gatherers.

The Inuit of Greenland survived for generations eating almost nothing but meat in a landscape too harsh for most plants. Today markets offer more variety, but a taste for meat persists. But most also endure lean times when they eat less than a handful of meat each week.

Year-round observations confirm that hunter-gatherers often have dismal success as hunters. The Hadza and Kung bushmen of Africa, for example, fail to get meat more than half the time when they venture forth with bows and arrows.

No one eats meat all that often, except in the Arctic, where Inuit and other groups traditionally got as much as 99 percent of their calories from seals, narwhals, and fish.

The Hadza get almost 70 percent of their calories from plants. The Kung traditionally rely on tubers and mongongo nuts, the Aka and Baka Pygmies of the Congo River Basin on yams, the Tsimane and Yanomami Indians of the Amazon on plantains and manioc, the Australian Aboriginals on nut grass and water chestnuts. They want meat, sure. But what they actually live on is plant foods. Our teeth, jaws, and faces have gotten smaller, and our DNA has changed since the invention of agriculture.

One striking piece of evidence is lactose tolerance. As a result, they stopped making the enzyme lactase, which breaks down the lactose into simple sugars. After humans began herding cattle, it became tremendously advantageous to digest milk, and lactose tolerance evolved independently among cattle herders in Europe, the Middle East, and Africa.

Humans also vary in their ability to extract sugars from starchy foods as they chew them, depending on how many copies of a certain gene they inherit. Populations that traditionally ate more starchy foods, such as the Hadza, have more copies of the gene than the Yakut meat-eaters of Siberia, and their saliva helps break down starches before the food reaches their stomachs.

There is tremendous variation in what foods humans can thrive on, depending on genetic inheritance. The Nochmani of the Nicobar Islands off the coast of India get by on protein from insects.

Studies suggest that indigenous groups get into trouble when they abandon their traditional diets and active lifestyles for Western living. Diabetes was virtually unknown, for instance, among the Maya of Central America until the s. Siberian nomads such as the Evenk reindeer herders and the Yakut ate diets heavy in meat, yet they had almost no heart disease until after the fall of the Soviet Union, when many settled in towns and began eating market foods. Today about half the Yakut living in villages are overweight, and almost a third have hypertension, says Leonard.

But scientists can tell whether our ancestors ate meat by analysing their bones and, says Cordain, "in the bones we dig up from Africa from two million years ago, and from Neanderthals in Europe, and Homo erectus in Asia, there's not a single exception. They were all omnivores and ate a lot of meat.

Zuk also mentions one anthropological theory: that before he were hunters, we scavenged other animals' prey. Sanders, who is chair of the Coeliac UK Health Advisory Committee, says he is inclined to agree with the statement that our bodies aren't designed to eat gluten, or at least quite so much of it, which is why coeliac's disease, gluten allergy and intolerance are all on the rise.

These sorts of decisions are a personal calculation and come down to common sense. Would you subscribe to a way of eating because it is billed as evolutionarily correct? Back to our roots: would humans be better off eating a paleolithic diet? Raw foodists and other campaign groups are eager for us to return to the sort of food our ancient ancestors ate. But how much truth is there in their various claims, and is there any real benefit for us in the 21st century?

Were our ancestors faddy when it came to their diet? Evolution lessons Guess what? Although cupcakes and crumpets were still a long way off during the Middle Stone Age, new evidence suggests that at least some humans of that time period were eating starchy, cereal-based snacks as early as , years ago. The findings, gleaned from grass seed residue found on ancient African stone tools, are detailed online Thursday in Science.

Researchers have assumed that humans were foraging for fruits, nuts and roots long before , years ago, but cereal grains are quite a new addition to the early prehistoric gastronomic picture. Plant domestication, most scientists think, made its debut some 10, years ago, with grain storage cropping up about 11, years ago. An ancient site in Israel yielded a hearty collection of grains, which were dated to about 23, years ago, according to a Proceedings of the National Academy of Sciences paper.

But such an early appearance of wild cereals in the human diet—as this new paper proposes—would push the assumed date of substantial grass-seed eating back more than 70, years. Mercader and a team from Mozambique's University of Eduardo Molande had uncovered hundreds of ancient artifacts in a limestone cave near Lake Nissa in Mozambique. Analyzing the surface of 70 of these tools, Mercader found some 2, granules of plant starch, which, he reasons, could not have accidentally come from growing plants in such dark reaches of the cave.