The Case Against Sugar

The Greek philosopher Aristotle was the first person to observe that sugary foods (he singled out soft figs in particular) caused tooth decay and at the time, no one believed him. Of course, in the centuries since Aristotle’s sage observation, the detrimental effects of sugar on oral health have become common knowledge and are expounded by dentists around the world. But why is sugar so bad? And is it possible to have the occasional sugary treat and still maintain good oral hygiene? This week we look at the relationship between sugar and dental health and how best to balance the two.

Why is sugar so bad for teeth?

Sugar on its own isn’t bad for teeth, it’s the acid produced by naturally occurring bacteria in the mouth that causes decalcification and demineralisation, ultimately leading to tooth decay.  There are two different strains of ‘bad’ bacteria which naturally occur in the mouth. These are Streptococcus mutans and Streptococcus sorbrinus and they feed off sugars, breaking them down into different types of sugar and ultimately into acid. Most foods contain some type of sugar but simple sugar (as in the sweetener) is the most fermentable, meaning it’s the fastest and easiest for the bacteria to break down in the mouth and is therefore the most likely to result in acid production. Time and the pre-existing condition of the teeth also play a role in whether the acids cause permanent damage.


What kinds of dietary habits increase the likelihood of tooth decay?

Sugary drinks

Liquid sugar in the forms of fruit juice, energy drinks, sports drinks and soft drinks have been linked by numerous studies to higher instances of tooth decay. One study found that consumption of sugary drinks directly correlated in the number of cavities developed by Australian children. Another study found that drinking even one occasional sugary drink increased the likelihood of losing between 1 and 5 teeth by 44%.


Sipping as opposed to gulping down sugary drinks has been shown to increase your risk of cavity development as it exposes your teeth to sugar for a longer period.

Sticky or chewy foods

Hard candy, breath mints, lollypops and chewable lollies are often associated with tooth decay as they not only stay in your mouth longer, but that they can also become stuck between the teeth and thus not easily washed away with saliva or drinks. This gives the bacteria longer to turn the sugar into acid.


Is there anything I can do to mitigate the effects of my sweet tooth?

Eat less sugar

A study found that limiting your daily sugar consumption to under 10% of your daily calorie intake can dramatically decrease the risk of tooth decay.

Drink sugary or acidic beverages with a straw

This will reduce the exposure of your teeth to sugar and acids.

Eat sugar as part of a meal

Eating or drinking sugary substances as part of a meal also limits the amount your teeth are exposed to sugar.

Improve the saliva flow in your mouth

Do this by eating raw fruit and vegetables as well as by staying hydrated with plenty of water.

Maintain good oral hygiene

Brushing and flossing your teeth at least twice a day keeps bacteria and acid levels in your mouth down to a minimum.