Drinking sports and energy drinks is the same as "bathing your teeth with acid", dentists say.
Researchers immersed samples of tooth enamel in 22 different brands of energy drink for 15 minutes at a time. They then left them in artificial saliva for two hours. The cycle was repeated four times a day.
This simulated "the same exposure that a large proportion of teens and young adults are subjecting their teeth to on a regular basis when they drink one of these beverages every few hours," researchers said.
Damage to the enamel was evident after just five days.
"Young adults consume these drinks assuming that they will improve their sports performance and energy levels and that they are 'better' for them than other soft drinks," said Dr Poonam Jain, from the Academy of General Dentistry (AGD) in the US.