Want to save your kidneys? Laying off the cola may help. National Institute of Environmental Health Sciences researchers asked more than 900 people—about half recently diagnosed with kidney disease and a similar number who were healthy—about the types of beverages they drank and how often they drank them. Study participants who drank two or more servings of cola a day had more than twice the risk of kidney disease. Diet and sugar-sweetened colas had the same risk. However, risk didn’t increase for people who drank two or more noncola beverages a day. Authors of the study, published in the journal Epidemiology, suggest the culprit may be cola’s phosphoric acid content. Citric acid is used in other beverages.