As if bottled water didn’t have a bad enough rap already, it turns out it can also contribute to tooth decay. Many dentists and pediatricians are concerned that children who only drink bottled water may experience more cavities, thanks to the fact that most bottled water does not contain the fluoride that tap water does. Even worse news: Most filtered tap water doesn’t contain the mineral either, the Washington Post reports (it notes the popular Brita filters don't strip fluoride, though).
No comprehensive study has been done on the subject of bottled water and cavities, but one small study shows “a slight tendency” toward more tooth decay in children who drank more bottled water. A South Australian study showed higher numbers: Children who didn’t drink fluoridated tap water had a 52.7% higher rate of cavities in their baby teeth. What can you do? Some dentists recommend fluoride toothpaste or supplements, but it’s also important not to get too much of the mineral, as it can cause tooth discoloration.
(Read more bottled water stories.)