It is well known that sugary drinks can harm teeth and promote tooth decay. But findings from the University of Melbourne suggest that some sugar-free drinks may be just as harmful. A team from the Oral Health Cooperative Research Centre has found that additives in many sugar-free drinks can still cause tooth decay.
The culprit lies in acidity. More specifically, bacteria in the mouth uses sugar to produce acid that can dissolve tooth enamel (the outer layer of the tooth). The issue, therefore, is acidity, and acidic drinks can also erode teeth even if they have no sugar. These include sports drinks, mineral waters and diet sodas.
The study identified the primary components of sugar-free soft drinks that were responsible for low pH levels (low pH means high acidity). These are phosphoric acid, sodium citrate, citric acid, and tartrates. Most common sugar-free drinks like diet soda and sports drinks contain at least one of these substances. On average, a sugary soda has a pH of around 2.72, a sugar-free soda has a pH of around 2.97, and a sports drink has a pH of 3.24. In comparison, milk has a pH of around 6.7 and pure water has a pH of exactly seven. On the pH scale (which ranges from 0-14), seven is considered neutral.
In total, 15 drinks, sugary and sugar-free, were tested on a collection of 70 human molars for their ability to cause surface loss and enamel softening. The sugar-free drinks were found to have no significant difference in their erosive potential. Sports drinks still caused enamel loss and decay, but not to the same degree. Of the drinks tested, only two sports drinks with higher calcium contents were not found to cause significant loss of enamel.
Sugar-free drinks and sports drinks do have other effects beyond tooth decay. Researchers realize that they are a preferred beverage for many people and so offer advice for anyone looking to better protect their teeth. Besides drinking more water between meals, consumers are encouraged to check product labels for the key acidic compounds (phosphoric acid, sodium citrate, citric acid, and tartrates) and gravitate towards drinks that either do not have these ingredients or ones that also contain calcium. If a sugar-free or sugary drink is consumed, it is best to do so when eating other food at the same time.
Sources for Today’s Article:
Paddock, C., “Some Sugar-free Drinks Can Also Damage Teeth, Experts Warn,” Medical News Today web site, November 30, 2015; http://www.medicalnewstoday.com/articles/303293.php.
“The Potential of Sugar-free Beverages, Sugar-free Confectionery and Sports Drinks to Cause Dental Erosion,” Oral Health CRC web site, November 26, 2015; http://www.oralhealthcrc.org.au/sites/default/files/Dental Erosion Briefing Paper_FINAL2015.pdf.