- Age 2 to 5: ~1 in 4 (~25%) had caries on their primary ("baby") teeth.
- Age 6 to 11: 21% with caries on their permanent ("adult") teeth.
- Age 12 to 19: 58% (!!!) with caries on their permanent teeth. Ouch!!
An obvious solution seems to be....Let's keep eating and drinking sweet-tasting stuff, but "sugar-free". I can't get cavities without sugar, right? It is commendable that the average person tends to be becoming more health-conscious, and this creates some pressure on the industries selling them food. The manufacturers of beverage and confectionery have responded by offering a wide range of "sugar-free", "low-sugar" and "healthy" products, commercialized as "diet" vitamin drinks, sport drinks, ice teas, fruit chews and so on. the sugar-free market is predicted to explode in the near future since there are clear links between high sugar intake and diabetes and obesity, and incidentally for a lot of people, dental caries. So things are looking promising for teeth, right?
Unfortunately, as it often turns out to be, it is not that simple. The mechanism of dental decay, or cavity, or carie, has been studied and shown to be, in short: bacteria settle on and around teeth, get sugar from diet (you probably never thought you were feeding so many little organisms while eating for yourself), use that sugar to make energy for themselves and reject their waste, an acid. That acid then attacks the surface of the tooth, basically dissolving and weakening it over time. Even brushing and flossing will not save the teeth if enough acid is poured over them, since the bacteria are relentless workers, going 24/7.
So why are sugar-free drinks and candies bad? Because they skip the middle man, the sugar, to go directly to the offending substance, the acid. They do not lead DIRECTLY to cavities, but many of them can dissolve/weaken/strip away the outer layer of a tooth. We have all felt our teeth as "chalky" or rough after drinking something acidic. This is caused by acids like phosphoric acids (sodas), citric acid (lemon and lime-flavored drinks, mainly; citrate is a chelator, a substance that binds calcium and take it away from the tooth) and tartrates. Confectionery add to this list malic and fumaric acids. Over time, the teeth will become "etched", or "eroded", showing a chalky surface, then eventually pits, scalloping and depressions that can reach deeper layers of the tooth, such as the dentin, and even the pulp! This direct damage will result in tooth sensitivity and will favor the development of caries.
This was demonstrated by researchers from the Melbourne University's Oral Health Cooperative Research Center. They tested a lot of sugar-free soft drinks, sport drinks and sweets. A link to the full study will be found at the end of my blog. In short, they found out that:
- Of the 15 soft drinks they tested, ALL OF THEM LED TO SIGNIFICANT EROSION OF THE DENTAL ENAMEL, WITH NO DIFFERENCE BETWEEN THE SUGARED AND SUGAR-FREE DRINKS.
- Soft drinks (carbonated, either sugared or sugar-free) were worse than sport drinks. Coca-Cola was used as a comparison and created the highest amount of surface loss.
- Milk drinks (basically neutral pH) did not create surface erosion.
- 6 out of 8 (75%) of sport drinks created significant loss and softening of enamel - but less than sodas (except for Gatorade lemon-lime, basically as bad as Coca Cola), therefore it appears to be the less of two evils. The two of them that did well had higher calcium levels, maybe something to look for (unfortunately, those two were also the losers of a palatability test, as luck would have it)!
- Interestingly, SPRING WATER, WHICH WAS USED AS A CONTROL, CAUSED THE ENAMEL SURFACE TO ACTUALLY GET HARDER.
- Sugar-free candies also proved to be an acidic disaster, since 2/3 of those tested had a pH level below 4.5, which means tooth demineralization.
I would like to point out that years ago, while in elementary school, for science class my daughter Caroline did the classic study of "what happens when you put teeth in various sodas". Her limited conclusions were that they ALL turned teeth softer and chalkier over a couple weeks, diet sodas somewhat less than sugared ones, clear ones (Sprite) less than dark ones (Pepsi, Coke), and the worst disaster was Mountain Dew, probably both full of sugar AND extremely acidic. She may have been onto something, even though it was never published unfortunately!
What would be the recommendations then? In short:
- Drink water, the best of all. FLUORINATED WATER IS EVEN BETTER (reminds me of something I have seen written recently in a blog somewhere!) :)
- Minimize the use of sugared and sugar-free drinks and candies. If you have to do it, do it "short and sweet" and as little as you can. Repetition and chronicity are the main offenders here. A quick acid bath does less damage than a prolonged one!
- If you have to eat or drink something acidic, do it at meal time, then rinse your mouth with water, and WAIT AN HOUR before brushing (saliva has elements that help fight the softening of the enamel, while immediate tooth brushing will tend to remove the softened/weakened enamel).
- If you want to suck on a candy, preferably use a sugar-free one, and menthol or mint flavored instead of the highly acidic lemon or fruit-flavored ones.
- Careful even with the real fruit juices! They contain sugar, are acidic, and can also create erosion if taken repeatedly or chronically.
- Sugar-free gum seems to be "ok", since some research has suggested that the saliva stimulation brings more of the good saliva stuff in and can actually help harden the enamel.
- See your dentist...Early dental erosion can be treated in the dental office with fluorides...But further damages may bring the need for all our armamentarium, from fillings to root canals to crown and bridges!
So we have a good study, with lots of numbers, that support those findings. Makes sense, right? And it rather supports our own observations as dentists.
Guess who does not agree? Of course, you got it: The American Beverage Association, a HUGE industry, was quick to point out that caries and erosion varied with individuals and is determined by a lot of factors. Duh....We knew that, but it does not exclude a fact that they are a MAJOR one in creating caries (it has been established that the main cause of dental erosion is repeated exposure to acids in food and drinks)*. Also it said that since low- and no-calorie sweeteners have been proven safe by the U.S. Food and Drug Administration and its counterparts around the world, then there should be "no reason why the average individual should avoid them". Duh and re-duh...Safe for what? Colon cancer? That does not prove it is not highly deleterious to teeth, an important part of people's life and health. Another great example of fighting for your commercial interests above everything else, including scientific findings...But then we have been used to that phenomenon with the tobacco companies. Nothing new!
While on the topic of the excess of sugars in kid's diet, another interesting study would be this one:
Although not without potential flaws from a scientific standpoint, I think it is interesting to note that the industry that came to call the study "flawed" was...The Sugar Industry Association. I am certain that it comes as a big surprise to you.
I hope this was of some interest for you. Do not forget to brush your teeth and floss!!
Christiane Ashba, DMD
* Salas MMS et al 2015. Estimated prevalence of erosive tooth wear in permanent teeth of children and adolescents. An epidemiological systematic review and meta-regression analysis. Journal of Dentistry, 43: 42-50.
Link to Study: