I went cold-turkey on all caffeine (coffee, tea, cola) about 12 years ago and just came across this article by Steven Reinberg that claims it may have been a good idea.  A report published in the October issue of the American Journal of Clinical Nutrition says that cola was associated with lower bone mineral density in women who were studied, although it did not seem to affect men’s bone density.  The reason for the effect could have to do with the level of caffeine or the amount of phosphoric acid in cola.  Apparently caffeine interferes with the absorption of calcium.  The article didn’t mention the effect of cola on the color of your teeth but I’ve always thought coffee, tea, and cola stain those pearly whites too.  Maybe that’s in the sequel study! You can read more about effect of cola on bone density for women at http://health.yahoo.com/news/167458.