5 Surprising Things That Age You
What it ages: Your bones
The science: Older women who drank a cola every day had significantly lower bone-mineral density than those who consumed less than one cola per month, according to a study in the American Journal of Clinical Nutrition. It's not exactly clear why cola had this effect, but the study researchers believe that it could be the combination of caffeine and phosphoric acid (which most other carbonated drinks don't have) that causes the problem.
What you can do: Cut back. Keep in mind that diet cola had similar effects and, to a lesser extent, so did decaf versions. If you need bubbles, try seltzer instead.