If you typically add a splash of milk to your teacup, you may have a new reason to smile.
Researchers from Canada found that adding milk to tea may prevent the drink from staining teeth.
"Tea is the second most consumed drink in the world, and the way it’s processed affects how teeth are stained, said lead study author Ava Chow, PhD, an assistant professor at the University of Alberta’s School of Dentistry, in a press release. "The more the tea is processed or oxidized, the higher its staining properties are. But we’ve found that the addition of milk to tea reduces the tea’s ability to stain teeth."
Water-soluble compounds called tannins are responsible for tea-related teeth stains. Dr. Chow and team looked at whether the addition of milk would make a difference.
When added to tea, milk was found to have a similar effect as using teeth bleaching products.
According to these researchers, the protective effect comes from a protein found in milk called casein, which binds to the tannins
This binding process may help keep teeth pearly white and free of stains.
Dr. Chow and team looked at extracted teeth, determining their natural color with an instrument called a spectrophotometer before exposing them to the tea.
The teeth were then soaked in either a solution of tea of a solution of tea with milk for 24 hours, after which they were reexamined with the spectrophotometer.
"The results we found showed that casein is the component of milk that is responsible for the reduction of tea-induced staining," Dr. Chow said. "The magnitude of the color change observed in our experiments is comparable to the color change seen by vital bleaching products and more effective than whitening toothpastes."
This study was published in the November 2014 issue of the International Journal of Dental Hygiene.
The University of Alberta funded this research. No conflicts of interest were disclosed.