The Journal of Nutrition conducted a study of sparkling and still mineral water. The study participants were asked to drink 1 liter of either the sparkling or still each day for two months, followed by two months on the other water. It was found that drinking sparkling water brought about significant reductions in the level of low density lipoprotein (LDL) cholesterol (generally regarded as a risk factor for heart disease), as well as a significant increase in levels of high density lipoprotein (HDL) cholesterol (generally taken to reduce heart disease risk). These and other biochemical changes induced by drinking sparkling water were estimated to reduce the women’s risk of developing heart disease over the next decade by about a third.