Senior nutrionist Rose Carr answers questions about maintaining our pearly whites.
Q: A friend told me sugar-free drinks were no better for my teeth than sugary drinks. Is that true?
A: It is true that frequent exposure to sugar-free drinks, as well as acidic foods, can harm your teeth. While bacterial plaque uses carbohydrates to produce acids that demineralise teeth, acidic food and drinks can harm teeth through dental erosion. This is where the enamel surface of teeth is slowly dissolved by these acids. Many sugar-free drinks, fruit juices and even muesli bars are high in acid, and dentists recommend they should be consumed with meals when they will be less harmful. Grazing and sipping throughout the day both increase the risk to our teeth as we may be effectively bathing them in acid.
Q: Is dried fruit healthy? I have heard it can be really bad for your teeth?
A: Dried fruit can be a healthy addition to our diets, although it is important to remember it is a very concentrated source of energy compared to the original fruit and won’t fill us up as much.
But dried fruit are not so teeth-friendly: they’re high in sugars (to feed the bacteria in plaque) and acids (to dissolve tooth enamel). And the stickier the dried fruit, the worse it can be, as the longer it sticks to your teeth the more damage can be done. Every time we eat or drink something containing carbohydrates, any harmful bacteria on the teeth will begin producing acid. The demineralisation process will then continue for 20-30 minutes or longer if food is stuck around the teeth. Again the advice is to avoid nibbling throughout the day.
Q: How can chewing gum after you eat help prevent tooth decay?
A: Studies have found that chewing sugar-free gum after a meal helps to clear food debris from the mouth and stimulates the production of saliva by as much as ten times the normal rate. Saliva plays an important role in reducing the risk of decay and helping to remineralise teeth. Saliva removes food debris from the mouth, neutralises the acids and provides calcium and phosphate to the teeth in the process of remineralisation. Saliva can also store and release fluoride, which inhibits the production of bacterial acid, remineralises teeth and hardens teeth so they’re less soluble.
While chewing sugar-free gum may be helpful, it is not a substitute for brushing teeth twice daily, and remember that chewing a gum containing sugar will feed the harmful bacteria and can increase tooth decay.
Q: Is there anything we eat that is good for teeth?
A: Reduced-fat milk and dairy products are a good source of a range of minerals – especially calcium – important for teeth. And although milk contains the sugar lactose, it has been shown to not harm teeth. Whole grains and nuts stimulate the flow of saliva because we need to chew them, while black tea can increase fluoride concentration in the mouth, helping protect teeth.
Finishing a meal with a hard cheese is teeth-friendly on two fronts: it stimulates saliva flow and it contains calcium, phosphate and casein which all help protect against demineralisation. Hard cheeses, however, are also high in saturated fats so we recommend moderation.