(ORDO NEWS) — A new study has shown that the human ability to digest milk sugar had no effect on the prevalence of consumption of dairy products.
The earliest finds that testify to dairy farming were made in Northwestern Anatolia and date back to the 7th millennium BC. Apparently, both it and milk processing technologies were brought by the first farmers to Europe along the Mediterranean coast and through the Balkans.
The very fact that adult prehistoric people drank milk has not yet been explained by scientists. The fact is that normally in our species there was no allele responsible for the production of lactase throughout life (this is called lactase persistence).
Lactase is an enzyme that breaks down and digests lactose, milk sugar. That is, genes that ensure the digestion of lactose were not present either in our ancestors who lived in Africa or in Neolithic Europeans. Nevertheless, they all drank milk.
The journal Nature published an article by an international scientific team led by Professor Richard P. Evershed from the University of Bristol (UK). The researchers summarized data on the findings of prehistoric remains of milk on ceramics and its traces in tartar.
Despite the fact that the importation of dairy farming to Europe through the Mediterranean and the Balkans is considered generally accepted, no traces of milk consumption have yet been found at the Neolithic sites of Northern Greece.
At the same time, already in the 4th millennium BC, the inhabitants of the British Isles and Ireland were quite experienced dairy farmers.
Around the same time, milk began to be intensively eaten on the territory of modern Denmark, and a little later – at the beginning of the 3rd millennium BC – representatives of the battle-axe culture on the territory of modern Finland (now there is the highest per capita milk consumption in the world).
Ancient DNA evidence shows that most, if not all, early Neolithic inhabitants could not break down lactose as adults.
Only in the Bronze and Iron Ages, due to the appearance of a new mutation, adults begin to assimilate milk normally, but not throughout Europe. The main Eurasian allele responsible for lactase persistence is still geographically distributed extremely unevenly.
In total, scientists used in their work data on the findings of 6899 remains of animal fat from 13,181 pots from 554 sites. All these sites have been reliably dated by radiocarbon dating. As a result, the researchers obtained information about the frequency of milk use throughout prehistoric Europe from 7000 to 1500 BC.
They found that the use of milk was widespread throughout the European Neolithic, and very widely, and corresponds to the spread of agriculture on the continent.
Comparing data on milk consumption with the results of ancient DNA analysis, scientists came to the conclusion that they do not match at all. That is, early assumptions that adults began to drink milk more often, because they had an allele that provides the breakdown of milk sugar, turned out to be wrong.
Milk consumption did not increase gradually throughout the European Neolithic from an initially low level: the level was immediately high, although the ability to break down lactose was then extremely rare.
The researchers thus proved that the scale of prehistoric milk consumption does nothing to explain the distribution of lactase persistence genes and, therefore, the intensity of selection for these genes.
At the beginning of 2021, a paper was published in the journal Nature Communications , the authors of which studied the same issue using African finds.
They, like their colleagues, came to the conclusion that ancient people drank milk as adults, although they could not break down lactose. Based on this, scientists stated that, most likely, people did not eat milk in its pure form, but fermented milk products, in which the lactose content is much lower.
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