10 March 2007

An article in the Proceedings of the Academy of Sciences of the USA shows that the ability to digest milk found among northern Europeans became dominant in that population only in the last seven thousand years. The research was done by scientists from University College, London (UCL) and Mainz University who looked in neolithic human remains for the gene that enables milk tolerance in adults.

The ability to digest milk and other dairy products is called lactase persistence or lactose tolerance and is down to an enzyme called lactase in the small intestine. Lactase breaks down lactose, the main sugar in milk, and enables it to be digested. Infants can digest milk, but in many adults the amount of lactase falls off and they become unable to handle milk. To be able to continue digesting milk people must have a variant gene which goes on producing lactase in adulthood and this is so for most people in northern Europe, the middle east, east Africa, and north America. The research suggests that the predominance of successful milk-digestion in northern Europe adults arose after the rise of dairy farming and proved evolutionarily very advantageous.

Note, about 95 percent of the White British group have the milk gene, the gene which enables lactase persistence. This means most English and Cornish people share this gene.

See BURGER J et al ‘Absence of lactase-persistence-associated allele in early neolithic Europeans’ in PNAS USA (2007) volume 104, pages 3736-3741, published 27 February 2007 online

and see Dienekes PONTIKOS Early Europeans unable to digest milk 27 February 2007

Other sources added 4 March 2009

BERSAGLIERI Todd et al ‘Genetic signatures of strong recent positive selection at the lactase gene’ in American Journal of Human Genetics June, 74, pages 1111-1120 (published online 26 April 2004)

BEJA-PEREIRA A et al ‘Gene-culture coevolution between cattle milk protein genes and human lactase genes’ in Nature genetics 1 December 2003, 35, pages 311-313 (published online 23 November 2003) with an erratum Nature genetics 1 January 2004, 36, page 106

A world map of lactose (in)tolerance is here

Update 4 August 2013
See The milk revolution on the blog of Dienekes Pontikos here.