Adding milk to tea helps negate the drink's tendency to stain teeth, according to Ava Chow, assistant professor at the U of A School of Dentistry.
Chow and a group of students took samples of extracted teeth from the U of A's oral surgery clinic and incubated them in tea or tea with milk. The results were dramatic - the teeth in the tea with milk showed significantly less staining.
Chow said it's worth noting that other studies suggest that adding milk to tea could negate the antioxidant and cardiovascular benefits of tea, so adding milk might not appeal to those who drink tea for these benefits.