Science In Action Index and Data

Most people lose the ability to produce lactase in adulthood. Only in some populations is the ability to digest lactose widespread in adults. These figures represent various methods of assessing adult lactose tolerance. Also note that some of the populations (for example Australian Aborigines) may have received the adult-lactase-persistence form of the gene by recent interbreeding.

POPULATION	LACTOSE INTOLERANT ADULTS
U.S. & Mexico
European Americans	2-19%
Latinos	52%
African Americans	70-77%
Native Americans	95%
Asian Americans	95-100%
Mexico	83%
Europe
Sweden	4%
Switzerland	12%
Spain	15%
Finland	18%
Estonia	28%
England	32%
Hungary	37%
Greece	88%
Jordan	79%
Africa
Southern Sudan (cattle herders)	17%
Ibo and Yoruba (Nigeria)	99%
Masai, East Africa	60%
Bantu, Gabon	65%
Fulani	25%
Asia
Japan	90%
Thailand	99%
Australia (Aborigines)	85%

Sources: Robert D. McCracken, "Lactase Deficiency: An Example of Dietary Evolution," Current Anthropology 12 (Oct.-Dec. 1971, pp. 479-517), Norman Kretchner, "Lactose and Lactase," Scientific American 277 (Oct. 1972, pp. 71-78), and others. Largely lifted from this site.
This table is referred to in the post on Evolution of Adult Lactose Tolerance at Science in Action.

posted by David