Soft drinks really do dissolve tooth enamel. This fact can be added to the litany of negatives that most people heard about soft drinks, including the lack of nutrients, the empty calories, their contribution to child obesity, and the way they tend to replace more nutritious drinks in many people's diets.
A study published in the journal General Dentistry in 2004 concluded that soft drinks “aggressively” harm teeth, although a spokesperson for the soft drink industry argued that the study was “not realistic.” The study featured slices of enamel from freshly pulled teeth that were placed in different types of soft drinks and weighed and measured before and after exposure. Damage to enamel begins within a few minutes of exposure, but it is cumulative exposure that leads to the most damage. In other words, people who drink soft drinks frequently are most at risk.
It is not the sugars in soft drinks that dissolve tooth enamel, but the high acid content. Diet and regular soft drinks dissolve enamel equally. The measure of acid in a liquid is measured on the pH scale, from 0 to 14. A pH of 7 is considered neutral and anything below this number is considered acidic. Water, as an example, has a pH of close to 7. In contrast, the average pH of the soft drinks sampled for the study was between 2 and 3. Battery acid has a pH of about 1.
The acids that dissolve tooth enamel that are present in soft drinks are citric acid and phosphoric acid. They are also found in sport and energy drinks, which harm teeth in the same way. Damage to the teeth happens very quickly. For example, fruit juice also has a relatively high acid content, but cola soft drinks caused ten times more damage within the first three minutes of exposure.
Other non-cola soft drinks and canned iced tea seem to be even worse. Other acidic drinks, such as brewed tea, coffee, and root beer are not as damaging, however. Beyond forgoing soft drinks, some experts urge drinking them through a straw in order to limit the amount of time that the teeth are exposed to the acid. Some also warn that eating large quantities of high-acid foods, such as lemons, yogurt, juice, and pickles, may cause similar damage to tooth enamel over time.