LONDON, Feb. 27 (UPI) -- British researchers say lactose intolerance, the inability to digest dairy products, in Europeans goes back to the Stone Age.
Genetic research by a team from University College London and Mainz University, Germany suggests that all European adults living between 6,000 BC and 5,000 BC were unable to absorb lactose, The Telegraph newspaper reported.
DNA tests on Neolithic skeletons from some of the earliest farming communities in Europe suggest the ability to digest milk was developed after cattle farming was introduced in Europe some 9,000 years ago, "making it the most rapidly evolved European trait of the past 30,000 years," said Dr. Mark Thomas of UCL.
In a release, Thomas said the ability to drink milk gave some early Europeans a big survival advantage, pointing to "the continuous supply of milk compared to the boom and bust of seasonal crops; its nourishing qualities; and the fact that it's uncontaminated by parasites, unlike stream water, making it a safer drink."
He said it "is the most advantageous trait that's evolved in Europeans in the recent past."