The Economist magazine recently ran a piece on research indicating that the ability to digest milk may explain how Europe got rich (28 Mar 2015).

‘Humans can digest lactose, the main carbohydrate in milk, only with the help of an enzyme called lactase. But two-thirds of people stop producing it after they have been weaned. The lucky third—those with “lactase persistence”—continue to produce it into adulthood. A recent paper [“The role of lactase persistence in pre-colonial development”, by C Justin Cook, Journal of Economic Growth, Dec 2014] argues that this genetic quirk helps explain why some countries are rich and others poor. . . .

‘Pre-colonial countries in western Europe tended to have the highest rates of lactase persistence . . . . Some 96% of Swedes had it, for instance. The lowest levels were in Sub-Saharan Africa and South-East Asia.

‘A one-standard-deviation increase in the incidence of lactase persistence, in turn, was associated with a 40% rise in population density.

People who could digest milk, the theory goes, used resources more efficiently than those who couldn’t.

They could extract liquid energy from livestock, in addition to the wool, fertiliser, ploughing power and meat for which others raised them. . . .

All this suggests that milk-guzzling societies could support higher population densities . . . .

No single factor can explain long-run economic outcomes, of course, but Mr. Cook’s idea may be worth milking.

Read the whole article in The Economist: Milk and economic development: No use crying—The ability to digest milk may explain how Europe got rich, 28 Mar 2015.

Related
ILRI Clippings Blog: Europe’s ‘milk revolution’: First Neolithic cheese-making, then a genetic mutation allowing lactose persistence, 3 Aug 2013.