Australian researchers tested 23 different types of sugar-free drinks—including soft drinks and sports drinks—and found those that contain acidic additives and those with low pH levels cause measurable damage to tooth enamel, even if they have no sugar.
Sugar is linked to tooth decay because it forms a plaque on the tooth surface that bacteria digest and covert to acid. This acid is what attacks the teeth by dissolving the outer layers of tooth enamel. Thus, drinks that are acidic—whether they contain sugar or not—can also erode teeth.
The researchers, from the Oral Health Cooperative Research Centre (CRC), based at the University of Melbourne, point out that many people are not aware that while reducing your sugar intake does reduce your risk of dental decay, the chemical mix of acids in some foods and drinks can cause the equally damaging condition of dental erosion. And while oral health experts generally agree that the use of sugar substitutes—including, for example, xylitol, sorbitol, and mannitol—in candy and beverages has helped reduce tooth decay in children in industrialized countries, the researchers contend that consumers should be aware that many sugar-free products remain potentially harmful to teeth due to their chemical composition.
The study measured the dental enamel softening and tooth surface loss following exposure to a range of drinks. The researchers found that the majority of soft drinks and sports drinks led to softening of dental enamel by between a third and a half. They also found that both sugary and sugar-free soft beverages—including flavored mineral waters—cause a measurable loss of tooth enamel, with no significant differences between the two types of drink. Moreover, six of the eight sports drinks tested by the researchers caused loss of dental enamel. The two that did not had a higher calcium content, the authors of the study noted.
The Oral Health CRC recommended that sugar-free products—including soft drinks, candy, and sports drinks—carry labels with information that helps consumers evaluate them in relation to their oral health.
Eric Reynolds, a professor at Melbourne Dental School and CEO of Oral Health CRC, points out that the research team even found that some sugar-free confectionary products labeled “toothfriendly” were erosive when tested. Reynolds and his colleagues recommend that people check for acidic additives, such as citric acid and phosphoric acid, in the ingredients list when deciding which sugar-free products to buy. They also suggest that after eating and drinking acidic products people should not brush their teeth immediately as this can remove the softened tooth layer. Instead, they recommend rinsing your mouth with water and wait for an hour or so before brushing. And if you drink acidic beverages—such as soda—on their own, then chewing sugarless gum afterward can help to increase saliva flow to neutralize the acid.
The researchers conclude that in their view current product testing and labeling regulations for foods and beverages are not sufficient to enable consumers to make informed choices in order to avoid the risk of dental erosion.
