Dairy pastoralism in the highlands of ancient Tibet

Roughly 3500 years ago, inhabitants of the Tibetan Plateau began exploiting dairy pastoralism as way to secure a mobile supply of food and adapt to the region’s cold, arid environment, according to an analysis of ancient protein samples (Sci. Adv. 2023, DOI: 10.1126/sciadv.adf0345)

Earlier studies, based on archeological findings, suggest that cultivating frost-tolerant barley was a key element of the strategy that enabled people to begin permanently occupying the plateau around that time. But those studies focused on select portions of the highlands that are lower in altitude than surrounding areas and more suitable to farming.

Searching for clues to explain how ancient people adapted to living 3700 m above sea level in one of the most inhospitable regions on Earth, an international team of researchers collected samples of dental calculus from the human remains of 40 individuals excavated from Tibet and western Qinghai. As dental calculus forms, it traps food proteins and other substances in a calcified matrix, sometimes securely storing dietary information from long ago.

The team, which includes Li Tang and Nicole Boivin of the Max Planck Institute for the Science of Human History, Jena, used radiocarbon dating and mass spectrometry-based protein sequencing techniques to analyze the samples. They conclude that dairy products from sheep, goats, and possibly cattle or yak supported ancient pastoralists in permanently occupying the Tibetan Plateau.They also note that dairy herding appears to have been a means of supplying nutrition to a wide range of individuals and was not limited by gender, social status, or age. The team found that one of the subjects was just six or seven years old, marking the first time that this method was used to identify milk proteins in an ancient child.