Friday 4 September 2009

A Short History of Milk Drinking


by Kathryn Hadley

It was previously believed that milk drinking began in dairy farming communities in northern Europe. Through a process of natural selection to compensate for vitamin D deficiencies due to a lack of daylight, communities in northern Europe were believed to have undergone a genetic mutation which enabled them produce the enzyme lactase necessary to digest the milk sugar lactose. The production of lactase is a characteristic known as lactase persistence. Although the majority of Europeans produce lactase throughout their life, most adults worldwide do not produce the enzyme lactase. However, the latest research by scientists from University College London has revealed that this genetic mutation first occurred, instead, in dairy farming communities in central Europe 7,500 years ago, in the region between the central Balkans and central Europe.

According to previous studies, dairying developed in south-eastern Europe soon after the arrival of farming. Milk proteins have been discovered, for example, in present-day Romania and Hungary in ceramic vessels which date back between 7,900 and 7,450 years. Traces of fats have also suggested that dairying began in England some 6,100 years ago. It is believed that Germanic and Celtic people practiced cattle dairying and drank significant amounts of fresh milk, however, it is most likely that milk was first used to make cheese, butter and yoghurt rather than drunk fresh.

Professor Mark Thomas, UCL Genetics, Evolution and Environment, explained:
‘Most Europeans continue to produce lactase throughout their life, a
characteristic known as lactase persistence. In Europe, a single genetic change
(13,910*T) is strongly associated with lactase persistence and appears to have
given people with it a big survival advantage. Since adult consumption of fresh
milk was only possible after the domestication of animals, it is likely that
lactase persistence co-evolved with the cultural practice of dairying, although
it was not known when it first arose in Europe or what factors drove its rapid
spread. Our study simulated the spread of lactase persistence and farming in
Europe, and found that lactase persistence appears to have begun around 7,500
years ago between the central Balkans and central Europe, probably among people
of the Linearbandkeramik culture. But contrary to popular belief, we also found
that a need for dietary vitamin D was not necessary to explain why lactase
persistence is common in northern Europe today.’

The results of the study were published last week in the journal PLoS Computational Biology in ‘The Origins of Lactose Persistence in Europe’ by Yuval Itan, Adam Powell, Mark Beaumont, Joachim Burger and Mark Thomas. The article is available on the website of PLoS Computational Biology. http://www.ploscompbiol.org/
Picture:
Map showing origin of milk drinking in Europe (UCL)

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