But the total amount of sugar you eat has less impact on cavities than the pattern in which you consume it. Tooth decay occurs when the bacteria that line the teeth feed on simple sugars, creating acid that destroys enamel. When you eat something sweet, it takes the bacteria about 20 seconds to convert it to acid, which then lasts for about 30 minutes.
That means that a can of soda is a lot less harmful to your teeth when consumed in a few minutes instead of over a couple hours with repeated sips, said Carole Palmer, a professor of public health and community service at Tufts University School of Dental Medicine. “Every time you present sugar to the bacteria, you’ll get acid formation,” said Dr. Palmer, who recently published a paper exploring dental myths in the journal Nutrition Today. “The things that are going to increase the risk of decay would not be the total amount of sugar at all, but what your feeding pattern is like. Are you someone that’s constantly sipping? Do you get one soda and keep it on your desk all afternoon? Do you get a cup of coffee with sugar and sip it all morning?”
For the same reason, many dentists advise parents not to use spill-resistant sippy cups too often, which have been linked in some studies to tooth decay in toddlers. Dr. Palmer points out that it’s not just sugar, but anything with acid, like diet soda. One study even found that sour candy was significantly more destructive to tooth enamel than regular, sweet candy because of its acid levels.
THE BOTTOM LINE Small amounts of sugar eaten frequently increase cavities more than large amounts eaten infrequently.
This article by Anahad O'Connerappeared in the 8-17-10 Science section of the New York Times:Any Questions? Call Dr. Bard Levey 914-271-6225
