The team identified milk protein entombed in dental plaque on the teeth of prehistoric farmers from Britain.
It shows that humans were consuming dairy products as early as 6,000 years ago - despite being lactose intolerant.
This could suggest they processed the raw milk into cheese, yoghurt or some other fermented product.
This would have reduced its lactose content, making it more palatable.
The team members scraped samples of plaque off the teeth, separated the different components within it and analysed them using mass spectrometry.
Read more: https://www.bbc.co.uk/news/science-environment-49650806