The hardest, most durable substance in your body is tooth enamel. But according to a new study, if you drink certain beverages on a regular basis you may be stripping that enamel away, opening the door to a variety of dental problems. Researchers in the UK exposed healthy molars and premolars to several types of beverages for a period of 14 days, equivalent to more than 12 years of regular intake. The study tested several sports drinks, energy drinks, fitness water, bottled lemonade, cola and iced tea. Surprisingly, cola didn't fare too badly. The greatest enamel damage was caused by sports drinks, energy drinks and lemonade. Fitness water, cola and iced tea were all found to be considerably less corrosive to enamel. This is not the first study to find a link between enamel damage and an intake of sports drinks. No surprise then that in a competitive industry that grosses about $5 billion a year, manufacturers are looking for ways to produce drinks that go easy on enamel. GlaxoSmithKline scientists are developing a sports drink with high calcium content (enamel is mostly made of calcium salts) and a higher pH level compared to other sports drinks. The results of one study indicate that this new drink (not yet on the market) may cause far less enamel erosion. Of course, most sports drinks are loaded with sugar, artificial flavorings and other additives that may cause more problems than just enamel loss over the long term. It gives a whole new meaning to the question they ask on one of those commercials: "Is it in you?"