British smiles have an unflattering international image, but a new study has put tartar from infamously bad teeth to good use. By analyzing the teeth of Britons from the Iron Age to the modern day they have leveraged a way to use proteins in tooth tartar to reveal what our ancestors ate. 

Dental plaque accumulates on the surface of teeth during life and is mineralized by components of saliva to form tartar or "dental calculus", entombing proteins from the food we eat in the process. Proteins are hearty molecules and can survive in tartar for thousands of years. That's good for science. 

Analyzing 100 archaeological samples from across Britain, as well as 14 samples from living dental patients and recently deceased individuals, the research team found that potential dietary proteins could be found in about one third of the analyzed samples. That's valuable. Archaeological tooth tartar had been shown to preserve milk proteins, but this shows it can also reveal more precise information about a wider range of food proteins, including those from plants.

In the modern samples, the researchers found proteins that reflected a global British diet, such as those related to potatoes, soybeans and peanuts, as well as milk proteins. Victorians ate porridge and cabbage, which shows British food was not that great then either.

Skeleton from the post-medieval period in Britain. Credit: Camilla Speller, University of York.

"It may offer a more precise way of identifying foodstuffs compared to other methods such as ancient DNA and isotope analysis as it can distinguish between different crops and indicate whether people were consuming dairy products, like milk or cheese," said senior author Dr. Camilla Speller from the Department of Archaeology at the University of York.