Direct evidence for milk consumption detected in the plaque of human teeth from the Bronze Age to the present day is presented in Scientific Reports this week. Such evidence can be used to investigate patterns in dairy consumption in different populations and how this behavior has evolved. For example, the dental record detects a decline in milk consumption in Greenland’s medieval Norse colonies that coincides with a point in time when it is predicted that the colony underwent a dramatic dietary shift.
Humans have used animal milk as a food source for at least 8,500 years, but direct measurements of milk consumption have been hard to come by, which has impeded efforts to understand in detail the origins, spread, and scope of ancient dairying. Christina Warinner and colleagues demonstrate that a milk-whey protein called beta-lactoglobulin (BLG) preserved in dental plaque can provide direct evidence of milk consumption. This marker can distinguish between cattle, sheep, and goat milk consumption.
By analyzing just under 100 dental samples from Europe, Asia and Africa dating from the Bronze Age to the present day, the authors detect milk proteins in the teeth of populations associated with a history of dairying traditions (Europe and northern Southwest Asia), but find no BLG in samples from Central West Africa, where dairy consumption was historically very low. The authors conclude that their BLG-detection method can be used to explore cultural, social and environmental factors that have influenced dairy consumption in the past.