But beverage industry disputes the claim, saying many factors contribute to enamel erosion.

Sports and energy drinks are causing irreversible damage to the teeth of teens and young adults in the United States, the authors of a new study claim.

High acidity levels in the drinks erode tooth enamel, the glossy outer layer of teeth, the researchers contend in the May/June issue of the journal General Dentistry.

“Young adults consume these drinks assuming that they will improve their sports performance and energy levels and that they are ‘better’ for them than soda,” study author Poonam Jain said in a news release from Academy of General Dentistry, which publishes the journal.

However, “most of these patients are shocked to learn that these drinks are essentially bathing their teeth with acid,” Jain said.For the study, the researchers analyzed acidity levels in 13 sports drinks and nine energy drinks. They found that acidity levels varied widely between brands and even flavors of the same brand. The effect on teeth of these acidity levels were assessed by immersing samples of human tooth enamel in each beverage for 15 minutes, followed by immersion in artificial saliva for two hours.

The cycle was repeated four times a day for five days, to simulate the exposure of teeth in teens and young adults who drink one of these beverages every few hours.

Damage to the tooth enamel was evident after five days, the researchers reported, and energy drinks caused twice as much damage as sports drinks.

Damage to tooth enamel is irreversible, the experts noted. Without the protection of enamel, teeth become overly sensitive and are more likely to decay and develop cavities.