Famine and Disease Drove the Evolution of Lactose Tolerance in Europe
Published:09 Aug.2022 Source:University of Bristol
Until now, it was widely assumed that lactose tolerance emerged because it allowed people to consume more milk and dairy products. But this new research, led by scientists from the University of Bristol and University College London (UCL) alongside collaborators from 20 other countries, shows that famine and exposure to infectious disease best explains the evolution of our ability to consume milk and other non-fermented dairy products.
While most European adults today can drink milk without discomfort, two thirds of adults in the world today, and almost all adults 5,000 years ago, can face problems if they drink too much milk. This is because milk contains lactose, and if we don't digest this unique sugar, it will travel to our large intestine where it can cause cramps, diarrhea, and flatulence; known as lactose intolerance. However, this new research suggests that in the UK today these effects are rare.