Those who prefer a bit of milk in their tea have a reason to smile: according to research from the University of Alberta, a splash of dairy in a cup of tea can help keep teeth pearly white.

Ava Chow, an assistant professor at the university’s school of dentistry, originally designed the project as a way to introduce undergrad students to research.

Using samples that had already been extracted from the mouth, Chow and her students compared the colour of teeth before and after soaking them in tea for 24 hours.

“Tea is the second most consumed drink in the world and the way it’s processed effects how teeth are stained. The more the tea is processed or oxidized, the higher its staining properties are,” Chow said in a news release. “But we’ve found that the addition of milk to tea reduces the tea’s ability to stain teeth.”

One batch of teeth were kept in a controlled solution of tea, while another batch were kept in a solution that was 20 per cent milk, 80 per cent tea. Both samples were kept at 37 degrees for a full day.

The teeth kept in milky tea, Chow said, showed significantly less staining.