Sports drinks are so acidic that they wear down tooth enamel—and brushing can worsen the problem.
How sports drinks weaken teeth. I'm Bob Hirshon and this is Science Update.
Sipping sports drinks all day won't turn you into a star athlete—but it might rot your teeth. This according to Mark Wolff of the New York University College of Dentistry. Although these drinks do contain sugars, which are known to damage teeth, Wolff says they’re not the main problem.
What's interesting about these drinks is they skip the entire process of putting sugar and bacteria together to make acids, and they deliver acids to you.
Mainly citric acid, which creates a tangy flavor, but also weakens tooth enamel. Wolff's team showed that cow teeth dunked in sports drinks for just an hour tended to soften up. What's more, Wolff says brushing right away can actually cause more damage by scraping off the softened enamel. He says if you want an all-day beverage, stick to water. I'm Bob Hirshon for AAAS, the Science Society.
Making Sense of the Research
Sports drinks have become incredibly popular over the past two decades, and now account for billions of dollars in sales and a significant chunk of the soft drink market. The first sports drink was invented to help the University of Florida's football team rehydrate and replace electrolytes after practices in the hot summer preseason. Since then, the drink has made its way onto the mass market, and has inspired many competitors. If you walk into a convenience store today, you may find entire refrigerator cases devoted just to sports drinks.
Because they were invented for athletes, sports drinks might seem healthier than soda or other sugary beverages. That may be why some people carry them around throughout the day, and sip them like water. However, in reality, sports drinks are mostly just sugar water, and few people who aren't serious competitive athletes have any need to be drinking them. Water is all you really need after moderate exercise.
Aside from providing empty calories, this study suggests that sports drinks may, over time, pose a significant threat to dental health. Normally, tooth decay is caused by bacteria that produce acids in the presence of sugar. (That's why you hear that sugar “causes” cavities, even though the cause is indirect.) However, as Wolff points out, sports drinks actually contain acids, which can wear away at your tooth enamel over time. Because this kind of damage affects the whole tooth and not one particular spot, you might not notice it right away. But eventually, it can weaken your teeth, leaving them more vulnerable to chipping and cracking.
As you heard, Wolff's team soaked cow teeth in sports drinks; after about an hour, the teeth showed significant enamel erosion. Although nobody holds one sip of a beverage in his or her mouth for an hour, the same effect could be achieved by sipping on a sports drink all day long. (In contrast, with other acidic beverages, like orange juice, people tend to drink them in one sitting.)
You also heard that brushing right away can actually make matters worse, by scraping the softened enamel right off. Wolff explains that your saliva will generally re-mineralize your teeth and harden the enamel after a certain amount of time has passed. However, if you brush your teeth before that happens, you can permanently remove the enamel.
Wolff notes that it's much better to drink water, which doesn't erode your tooth enamel, than to drink sports drinks and then wait for your teeth to re-mineralize. In fact, your saliva may not be able to repair all the damage, if you drink sports drinks too often. Wolff says he's seeing more and more patients with significant enamel erosion, due in part to the sports drink craze.
Now try and answer these questions:
How do sports drinks erode enamel?
How is this different from the way sugar leads to cavities?
Why are sports drinks more problematic than other acidic beverages?
Can you think of other products associated with health or fitness that may actually cause health problems?
You may want to check out the April 24, 2009 Science Update Podcast to hear further information about this Science Update and the other programs for that week. This podcast's topics include: why bone loss can be slowed but not reversed, genes that turn carbohydrates to fat, how sports drinks damage teeth, and more.
For a different take on tooth enamel, check out the National Geographic News article Radiation in Teeth Can Help Date, ID Bodies, Experts Say.