What’s This About Soy Milk?
Posted on Monday, July 30th, 2012
A sure way to grab attention is to play contrarian and make claims that go against common sense. In the health world, these often run along the lines of “what you thought was bad is actually good for you, and what you thought was good is actually bad.” To wit, an item that made the news earlier this month:
Soy milk may be worse for your teeth than cow’s milk, a new study suggests.
As if cow’s milk were bad for your teeth? (There are good reasons some people choose to avoid it, but keeping their teeth in good shape isn’t one of them.) But we digress.
What to make of this claim that soy milk can wreck your teeth?
To be frank, not much.
The study discussed in the above news item, published in the Journal of Dentistry, compared acid production by s. mutans when feeding on “soy beverages” to production when feeding on cow milk. Microbes in dishes of cow milk produced acid at a rate “five to six times lower at pH 6.5 than in the soy beverages and three to five times lower at pH 5.5.”
The dental concern is that the greater acidity may lead to more tooth decay, at least in comparison to cow milk. Only more research, though, can confirm if this is so. It’s a little early to be declaring soy milk “bad for teeth” (even if there is, as in the news item, a question mark tagged onto the phrase).
One other thing to keep in mind is that conditions in the mouth turn more acidic whenever we eat anything. After about a half hour, pH returns to normal and you can safely brush your teeth. But one other new study suggests a potential complication when it comes to oral pH: the potential impact of tooth erosion.
Published in Caries Research, the study found that conditions grew more acidic after drinking orange juice with a water chaser – and stayed that way longer – for people with degraded tooth enamel than those with enamel intact. Their saliva’s ability to neutralize acids was also impaired.
A bit of a vicious cycle seems at work here: too much exposure to acids leads to erosion, while erosion may contribute to conditions that encourage even more erosion.
How to avoid the problem? Here are some good tips.
Image by Timothy Valentine, via Flickr