Acid in drinks and how it causes cavities

Here at Lincoln Pediatric Dentistry, we spend the majority of our time educating our patients and their parents about how to prevent decay. Of course we talk about brushing and flossing, but one huge factor in preventing cavities is avoiding sugary and acidic drinks that can cause enamel erosion. Learning if a drink contains sugar is fairly easy; you just need to read the nutrition label. But it can be more difficult to know if a drink is acidic.

Acidity is measured on the pH scale. The scale ranges from 0 to 14 with 0 being very acidic (battery acid) and 14 being very basic (liquid drain cleaner). Water is considered neutral at 7, which is ideal!

It is interesting to know that a drink can be acidic without containing much/any sugar. How can this be possible? Take Diet Coke for example. While it does not technically contain any sugar, its pH level is considered very acidic at 3. Below is a short list of some popular beverages and their pH levels.

For a full list of pH values of sodas, energy drinks, juices and sports drinks, click this link:

The pH of beverages in the United States

While some of these pH values may not be very surprising, some are quite shocking. You may think that sodas are the worst beverage choice, but notice that Grape Powerade and Orange Gatorade are even more acidic than Diet Coke at lower than 3 on the pH scale.

Naturally, the best way to prevent enamel erosion is to avoid drinks under 5.5 on the pH scale. Avoid carbonated drinks by swapping them out with milk, water or tea. If you do choose an acidic beverage, alternate sips of water with the beverage. This will help wash the acid out of the mouth. Sipping the beverage through a straw can also help keep it off your teeth. Once you have finished the drink, wait at least a half an hour before brushing. Why? The acid softens the tooth’s enamel, so brushing immediately after you finish an acidic drink can actually cause damage. It is best to rinse with tap water then brush.

So remember cavities form in acidic environments. While sugar and acid separately are bad for your teeth, when a drink is high in sugar AND very acidic, it is working against you in two ways. We know it can be difficult to make the right choice every time. When in doubt, choose water! Your enamel will thank you!