If something is labelled “diet” — it must be good for you, right? It depends. Usually diet drinks do not contain sugar, which is important in reducing the risk of dental decay. However these beverages are often still acidic which can lead to tooth erosion.

Diet Coke, Coke Zero, Pepsi Max, and many other diet versions of popular soft drinks are marketed as a healthier alternative to regular soft drink. As the awareness of the potential harm that too much sugar can do, these options have exploded in popularity.

From a nutritional perspective, eliminating sugar means eliminating calories. Calories are the measure of energy  in a particular food or drink, so it sounds like a great deal to consume something that tastes good, and won’t make you fat.

But it’s not as simple as that…

Diet soft drinks contain artificial sweeteners (usually Aspartame) which many believe can have some important health impacts. Consuming these sweeteners can cause headaches, and some research suggests it could be associated with an increased risk of osteoporosis, depression, and type 2 diabetes.

While some of these associations may be correlations, not causations — but it begs the question — is it a good idea to consume something with no nutritional value?

From a Dental perspective…

The impact of diet soft drink is far easier to quantify. The pH of Coke Zero is 3.1, Diet Coke is 3.4, and Pepsi Max is 2.7. Any substance with a pH below 5.5 can cause tooth structure loss, sensitivity, and discolouration, and in our clinic diet soft drink consumption is often found to be the primary cause of dental erosion.

Diet soft drinks can be just as harmful as regular soft drink.
Diet soft drinks can be just as harmful as regular soft drink.

Even though the bacteria which cause dental decay need sugar to cause cavities, they also thrive in an acidic environment. So even if decay forming bacteria are not being fed by the sugar in soft drink, patients who consume a lot of diet soft drink are still at high risk of developing decay.

The dental symptoms of consuming too much diet soft drink include

  • Tooth sensitivity.
  • Tooth discolouration (yellowing or darkening).
  • The visible loss of tooth structure (usually seen as a flattening of the biting edges of the front teeth).
  • Increased risk of dental decay.

In general, most food and drink is OK in moderation. But don’t be fooled into thinking that diet soft drink is good for you. If you do like to enjoy one or two of these beverages on occasion, make sure you’re using a high mineral tooth paste like Pronamel, and you should also consider using a remineralising agent such as Tooth Mousse.


If you would like to discuss your diet, lifestyle and oral health needs book a consultation with Dr Kate Amos or Dr Sam Rosehill at Ethical Dental on 6652 3185 or book online.

To learn more about how your diet may be affecting your oral health check out our articles ‘Did you know…that sports drinks can be just as bad as soft drink?’, ‘Alcohol Consumption and Oral Cancer’ and ‘Did you know… too much dietary acid causes tooth erosion?’.


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