How many Australian adolescents have frequent toothache?

Eight percent and could it be from sugar-sweetened beverages? This study highlights toothache is 2.5 times more likely where > 500ml per day of sugar-sweetened beverage is consumed

Soft drinks, fruit juice and energy drink contribute to sugar intake

Too much sugar in the diet is a public health concern and linked to unhealthy weight gain and dental caries.  WHO recommend sugar intake should be less than 10% of total energy intake and substantial oral health benefits have been recognised when sugar intake is less than 5% of total energy intake (1).

An earlier blog discusses the WHO sugar recommendation

However, in Australia, many adolescents exceed this recommendation and sugar contributes to 15% of adolescents energy intake (2).  Sugar-sweetened beverages (SSB) are a contributor of added sugar in the Australian adolescent diet.  Dr Louise Hardy, from the University of New South Wales, looked at the oral health issues (OHI), the prevalence of obesity and its association with the consumption of sugar-sweetened beverages in Australian adolescents in her recent study (3).

What causes tooth decay?

Acid is a by-product of bacteria in the mouth, feeding on sugars from food.  It is the acid which decays the teeth.

The authors (from the study) say …

There were clear and consistent associations between OHI and the consumption of energy, sports drinks and flavoured water, more so than the traditional soft drink. Additionally, the prevalence of unhealthy weight was higher in the consumers of these same drinks.

This was a concern, as the perception of these, more modern, beverages as a healthy alternative is at the expense of healthy teeth.

Sports drinks are primarily marketed to provide hydration during physical activity.  Energy drinks are promoted to provide increased energy, enhance mental alertness, physical performance and better health with added antioxidants and vitamins but this is all detrimental to teeth, and there are other discussions about whether young people require drinks with caffeine and other stimulants.

Reducing the frequency and volume of SSBs to young people could have a significant impact on adolescent oral health.

Source of data and its limitations

This cross-sectional study (3) used data collected from the 2015 NSW Schools Physical Activity and Nutrition Survey (SPANS).  The 3,671 participants were aged between 10 and 16 years.

Trained field staff collected height and weight measurements and a weight to height ratio (WtH) were calculated.

The consumption of SSB data was collected through a validated short food frequency questionnaire (FFQ) and included soft drinks, diet soft drinks, sports drinks, fruit juice, flavoured water and energy drinks. Even though the FFQ was validated, it did have inconsistencies with the quantities of SSB’s consumed e.g. the question on energy drinks was about times consumed (per week) whereas the other SSB questions collected volume per day or week, so some adjustments were made to standardise this inconsistency.

There was no clinical dental examination to determine the prevalence of OHI.  Instead, two questions were asked from the National Dental Telephone Survey.  These validated questions have a strong correlation with the presence of dental caries.  An OHI was defined where there were ‘often’ or ‘very often’ toothaches or problems with the mouth or teeth so some foods were avoided.

The statistical analysis considered the frequency of teeth brushing (OHI) and level of physical activity (for weight), along with age, sex, socio-economic status, residence (urban or rural) and language background.

As expected the data showed an association between SSB and OHI

In total, 8% (266 adolescents) of the study group experienced frequent OHI.  Eleven percent (384 adolescents) of the study group did not drink SSBs.

The overall outcome showed 16% (539 adolescents) of the study group drank more than 2 cups of any SSB per day and were 2.5 to 3 times more likely to have OHI than someone who did not drink SSBs.  The result was dose responsive, therefore, the prospect of an OHI increased as consumption of SSB’s increased.

Looking at one class of SSBs, the prevalence of OHI was highest in diet soft drinkers but this only affected 2% (83 adolescents) of the study group.  These 83 adolescents consumed more than 1 cup of diet soft drink per day and were 4-5 times more likely to have OHI than the remaining 3377 adolescents, who consumed less than 1 cup of diet soft drink per day.

For consumers of diet soft drinks the prevalence of OHI was considered high and without a reason, even though it affected only a small group the researchers felt it could be worth exploring whether the prevalence was due to the artificial sweeteners or some other habit undertaken by this segment of the population i.e. sucking confectionary?

In another class, 20% (671 adolescents) of the study group regularly consumed energy drinks and were twice as likely to have OHI as those who did not drink energy drinks at all.

One person could be in more than one class of SSB as more than half the study group consumed a range of SSBs.

But no association between SSBs and weight …

In total, 27% (961 adolescents) were in an unhealthy weight range.

The overall result did not show any association of SSBs with unhealthy weight.  This is not consistent with meta-analyses suggesting higher intakes of SSBs are associated with unhealthy weight outcomes.  However, this study showed regular consumers of energy drinks were 1.3 to 1.6 times more likely to have an unhealthy weight or WtH ratio than non-consumers of energy drinks.

This study adds weight to the argument that adolescents should reduce their consumption of sugar-sweetened beverages

NSW Ministry of Health funded this study and the authors state no conflicting interests.


  1. World Health Organisation. Guideline: Sugars intake for adults and children. Geneva: World Health Organisation, 2015.
  2. Lei L, Rangan A, Flood V, Louie J. Dietary intake and food sources of added sugar in the Australian population. British Journal of Nutrition 2016;115:868-77. doi: 10.1017/S0007114515005255.
  3. Hardy LL, Bell J, Bauman A, Mihrshahi S. Association between adolescents’ consumption of total and different types of sugar-sweetened beverages with oral health impacts and weight status. Australian and New Zealand Journal of Public Health:n/a-n/a. doi: 10.1111/1753-6405.12749.