Switch to water, or to 100 percent fruit juices that don't require artificial sweeteners.

Unkind cup: Too much diet soda may be bad for your kidneys.

RODALE NEWS, EMMAUS, PA— Diet soda may speed up the decline of your kidneys, according to a new study. Many people assume that artificial sweeteners make diet soda bad for you—as in the numerous Internet rumors linking aspartame, the most widely used artificial sweetener in diet sodas, to everything from cancer to multiple sclerosis to Gulf War syndrome. Those rumors have never been confirmed, but the new study does cast doubt on the ubiquitous sweetener.

THE DETAILS: Research exploring whether its effects on kidneys makes diet soda bad for you was presented at the American Society of Nephrology's annual Renal Week conference. Researchers collected data from 730 diabetic women participating in a kidney study that was part of the larger Nurses' Health Study. The women had supplied data at three points over the course of six years on how often they consumed sugar-sweetened beverages or artificially sweetened sodas—less than once a month, one to four times per month, two to six times per week, one to two per day, or more than two per day. The researchers then collected data on blood tests that had been performed 11 years apart to look for certain elements that signal healthy kidney functioning. After adjustments for age, diet, and lifestyle factors like smoking, the data revealed that women who drank more than two diet sodas per day had a twofold increase in risk for kidney function decline.