For those of us cutting back on calories, diet sodas may be a convenient substitute for sugary, high calorie drinks. According to a new study, however, drinking two or more diet sodas a day may take a serious toll on your kidneys in the long run. The study was done by researchers at Brigham and Women's hospital, led by Julie Lin, MD, MPH, an assistant professor of medicine at Harvard Medical School. The researchers followed over 3,000 women who had submitted dietary information for the Nurses' Health Study and found that women who drank two or more diet sodas a day experienced a 30% decrease in kidney function between 1989 and 2000. “30% is considered significant,” said Lin.

Even when researchers took other factors into consideration, factors like age, high blood pressure, diabetes, and physical activity, the connection between diet sodas and kidney function remained the same. Drinking less than two diet sodas a day, however, didn't seem to have a harmful effect on kidney function, nor did the researchers find a connection between impaired kidney function and drinking other artificially sweetened beverages, such as juices or teas.