More bad news for soda drinkers (that includes both regular and diet sodas). In 2007 a study was published in General Dentistry on the  acidity of some common soft drinks, and what effect those soft drinks had when a recently extracted tooth was submerged in them for 2 days. This study was done to cause the tooth decay that soda causes.

What is pH?

Acidity ranges in general go from 0 to 14, with a pH of 7 being neutral. Pure water is typically considered neutral at pH 7, where tap water has been measured having a pH of 7.67, a slight base.

For more on Acids, Bases, and pH.

Here is a chart of the ph of some common household items:


 

Solution

pH
Acidic Lemon Juice 1.6-1.8
Vinegar 2.5
Milk 6.3-6.6
Saliva 6.2-7.4
Neutral Pure Water 7.0
Basic Blood 7.4
Egg Whites 7.6-8.0
Milk of Magnesia 10.5


 

The pH of soda pop

So how did soda fare in this study? As you could probably guess, not too well.

Here is a chart of the acidity levels of some common sodas:


Soda Name

pH
Coke 2.525
Diet Coke 3.289
Pepsi 2.530
Diet Pepsi 3.031
Dr. Pepper 2.899
Diet Dr. Pepper 3.169
Cherry Coke 2.522
RC Cola 2.387
Mr. Pibb 2.902
Mountain Dew 3.229
Diet Mountain Dew 3.365
Squirt 2.898
Surge 3.004
Slice Orange 3.059
Sprite 3.202
7 Up 3.202
Diet 7 Up 3.706
Lemon Brisk 2.868
Lemon Nestea 2.969
Mug Root beer 4.038
Tap Water 7.67


 
The worst offender was RC Cola, Cherry Coke, Coke and Pepsi not far behind. The least acidic soda was Mug Root Beer at a pH of 4.

Results of Study

The study was done by submersing teeth in soda, so although this does not show real-life drinking patterns, it does show that the longer soda is exposed to teeth, the more corrosion does occur. The authors of the study suggest drinking soda through a straw to mitigate any contact with your teeth – and that definately means no swishing. 

Finally, as you can tell, the pH of some sodas equals the pH of Vinegar! If that isn’t enough to turn your stomach, I don’t know what is!

Source: Commercial soft drinks: pH and in vitro dissolution of enamel – Jain, Nihil, Sobkowski, Agustin