Regular or Diet Soda – Which is Worse for Your Teeth?

A new study reveals a surprising result when comparing the effects regular and diet sodas have on tooth decay.


Replacing sugary sodas with diet sodas is one controversial recommendation for losing weight. Plus, everyone knows that sugar consumption is a leading cause of tooth decay and yet another reason for choosing artificially sweetened beverages over naturally sweetened beverages. But is this reasoning sound? Are diet sodas and the like really better for your teeth than sugar-laden sodas?

According to the recent findings of new study revealed by Australian scientists, the answer is “No.”

Researcher Laureate Professor Eric Reynolds, CEO of the Oral Health Cooperative Research Centre, University of Melbourne says that it’s important for health-conscious consumers to be aware that diet and sugar-free beverages and candy can still wreak havoc on your dental health.

As part of a dental erosion study at The Oral Health Cooperative Research Centre in Melbourne, Australia, researchers tested the erosive potential of 15 beverages commonly sold in Australian school canteens, including three sugar-free soft drinks. The drinks were tested on extracted human molars that were free of dental caries.

What the data showed was that the majority of the beverages tested caused softening of the tooth enamel by 30 to 50 per cent. Furthermore, there was no significant differences found when comparing the damage caused between sugar-containing and sugar-free soft drinks – including the increasingly popular flavoured mineral waters.

So why are sugar-free beverages as equally damaging to teeth as regular soda? According to the study, it has to do with a combination of acidic pH levels and the ability of some food acids to bind to calcium. The study reports that many of the beverages have pH levels as low as 2.4 – a result of including flavouring food acids such as phosphoric acid, sodium citrate, citric acid and tartrates to the drink formulations, all of which actively bind to the protective calcium in teeth.

“Many people are not aware that while reducing your sugar intake does reduce your risk of dental decay, the chemical mix of acids in some foods and drinks can cause the equally damaging condition of dental erosion,” stated Eric Reynolds for CBS News.

The researchers intend for their findings to be used toward better consumer information and product labelling to help consumers make better oral health-related decisions when they choose what to eat or drink.

And while some may argue that acidic fruits such as oranges, which have a high concentration of citric acid in them, could be considered enamel-damaging as well, the authors of the study point out that, “Yes, natural foods like oranges and lemons contain citric acid, but we don’t tend to eat these in excess and frequently. There are also other ingredients in fruit that counter dental erosion. When you add purified citric acid to carbonated drinks, they have the potential to do damage.”

The following are recommendations by the authors of the study on what you should do to keep your teeth healthy:


Tips to avoid tooth erosion and decay

• Fluoridated tap water is always the best option for teeth. Milk is excellent because it’s not erosive at all. But be aware that bottled water doesn’t have the same benefits, particularly for children.

• Sports drinks, even sugar-free kinds, are also bad for enamel. Water is just as good at rehydrating.

• Sugar-free candy often contains citric acid and can cause significant problems. It’s best to keep consumption of candy of all kinds to a minimum.

• After drinking or eating acidic foods and beverages, don’t brush your teeth straight away. Some people brush too hard and wear away the enamel with the combination of abrasion and erosion. It’s better to drink tap water, rinse it around and harden up the enamel before you brush.

• Check ingredients for acidic additives, especially citric acid (ingredient number 330) and phosphoric acid (ingredient number 338).

• Have regular check-ups with your oral health professional. – by Tim Boyer



Why those sugar-free products damage your teeth” by Laureate Professor Eric Reynolds, CEO of the Oral Health Cooperative Research Centre, University ofMelbourne.

Oral Health CRC Briefing Paper: “The potential of sugar-free beverages, sugar-free confectionery and sports drinks to cause dental erosion”.