Despite Being Lactose Intolerant, Ancient Europeans Drank Milk: Study

Scientists have concluded that ancient Europeans consumed milk for millennia despite the potential digestive issues it may have brought on, throwing doubt on beliefs about how humans developed to handle it. 

Scientists have long conjectured that in societies where domesticating dairy animals was common, an enzyme required to prevent any stomach discomfort emerged quickly, as reported by the Washington Post. 

According to the study, individuals who could tolerate milk benefited from a new source of calories and protein. They passed on their genes to more healthy offspring than individuals who lacked the genetic trait known as lactase persistence, which enables individuals to continue to digest the sugar in milk as adults. 

However, a recent study proposed a radically different idea, contending that side effects like gas, bloating, and cramps were not sufficient to change the course of evolution for the genetic mutation. 

Before they developed the ability to digest it, prehistoric people in Europe may have begun ingesting milk from domesticated animals, according to the study’s authors. 

More than one hundred researchers from various disciplines, including genetics, archaeology, and epidemiology, worked together to develop the study published in the journal Nature. The researchers plotted the predicted milk intake in Europe between 9,000 and 500 years ago. 

Lactase persistence was not frequent until roughly 1,000 BCE, nearly 4,000 years after it was first discovered. According to the researchers’ analysis, animal fat remained in pottery from hundreds of archaeological sites and DNA samples from old bones. 

Furthermore, they contended that carrying the mutation became essential for survival during times of famine and epidemics rather than during periods of abundance, as undigested lactose might result in deadly bowel diseases. 

They concluded that individuals were more inclined to consume milk when all other food sources had run out and that during those times, diarrhea was more likely to worsen from a moderate to a lethal disease using archaeological records to identify periods when populations shrank. 

The study raises “fascinating questions” about whether some people who think they are lactose intolerant “might actually be fine if they drank milk,” according to George Davey Smith, an epidemiologist at the University of Bristol. He collaborated with the researchers on analyzing recent data on milk and lactase persistence in current populations. 

According to a 2014 smaller study, the mutation that enables people to digest lactose did not arise until 3,000 years ago in DNA samples from Hungary, although it might have emerged as long ago as 7,000 years ago in regions like Ireland where cheesemaking became common. 

According to Amber Milan, a specialist in dairy intolerance at the University of Auckland, the idea that the lactase mutation only became crucial to survival when Europeans started experiencing epidemics and famines is a “sound theory” and is “supported by previous research of drivers of genetic selection.” 

However, she added that she is unsure whether the new study “entirely rules out that widespread milk consumption was the evolutionary force behind lactose tolerance” due in part to the fact that the genetic data was obtained from Biobank. Biobank is a British biomedical database that contains genetic and health information from about 500,000 individuals. 

The main European genetic variant for lactase persistence has also received a lot of attention from the authors, which, while appropriate for this study, “may have missed other genetic variants that result in lactase persistence,” according to Milan.