There’s research that links drinking certain types of soda with weaker bones—but carbonation doesn’t seem to be the problem.(In fact, sparkling mineral waters sometimes contain a little calcium and magnesium.) The likely cause? Phosphoric acid, which is unique to colas. When the body breaks down this compound, the acidity (or concentration of free hydrogen ions) of the blood increases. To neutralize acidity, hydrogen ions bind with minerals, including calcium and magnesium. If they’re not available in the blood the body draws calcium from bones. The occasional cola drinker probably needn’t worry. The real risk is for those who drink cola every day.