A recent study has identified the first direct evidence of milk consumption by humans anywhere in the world, by analysing the teeth of Neolithic individuals from Britain.
Researchers led by archaeologists from the University of York used proteomic analysis to study ten skeletons from three early and middle Neolithic sites in Britain: Hambledon Hill, Hazleton North, and Banbury Lane. This process involved scraping samples of calculus from their teeth, extracting the proteins within it, and analysing them using mass spectrometry. As dental plaque mineralises and turns into calculus it entraps and preserves ancient biomolecules and microdebris. This means that the calculus contains a direct record of a person’s diet. The study found beta-lactoglobulin (BLG), a milk protein, in seven of the individuals, demonstrating that they had been consuming milk in some form.
There has long been debate surrounding the origins of dairy consumption in European populations, as well as when the ability to digest milk as adults developed. In order for humans to digest lactose, the main carbohydrate in milk, it has to be broken down by lactase so that it can be absorbed within the intestine. This ability is present in infants, but humans naturally stop producing lactase after weaning, unless a genetic mutation is present that allows for its continued production into adulthood – this mutation is known as lactase persistence (LP). It was previously assumed that positive selection of LP (and therefore the ability to digest milk) developed at the same time as dairy farming, but recent work suggests that LP remained rare in European Neolithic, and even Bronze Age populations, and is likely to be a more recent development.
The fact that the Neolithic people examined in this study were consuming milk, whilst also most likely being lactose intolerant, is intriguing. It is possible that they were consuming very small amounts of raw milk, or that they were eating milk that had been processed in some way, for example as cheese, or in the form of fermented milk products such as yoghurt, buttermilk, or kefir.
It is hoped that in the future it may be possible to determine whether different amounts of dairy, or dairy from different animals, were being consumed by different members of society, allowing for greater examination of British Neolithic social structure, as well as of milk consumption and processing.
The paper detailing this study and its results can be read for free at: https://link.springer.com/ article/10.1007/s12520-01900911-7