New research shows that dairy products have made life easier for thousands of years. Even in places that are a challenge for anyone, like the Tibetan Plateau - the “roof of the world.”

Genetic engineering due to natural selection at several genomic loci certainly made early Tibetans better able to survive high elevations, but those did nothing for calorie requirements. A new study finds that dairy made it possible. Ancient proteins from the dental calculus of 40 human individuals from 15 sites across the interior plateau show that dairying was introduced onto the hinterland plateau by at least 3,500 years ago.

Dental calculus of the highest altitude individual investigated in the study (cal. 601-758 CE). Credit: Li Tang

Goats, sheep, possibly cattle and yak, everyone was consuming dairy. It made areas too extreme for crop cultivation. The work is possible because proteomics is more advanced than analyzing the remains of animals and the interiors of food containers for evidence of dairying.  All the individuals with evidence for milk consumption were recovered from sites higher than 3700 meters above sea level; almost half were above 4000 meters above sea level, with the highest at the extreme altitude of 4654 meters above sea level.