Diet Soda, Sodium Tied to Kidney Trouble: Studies

Nov. 3 -- MONDAY, Nov. 2 (HealthDay News) -- A diet high in salt or artificially sweetened drinks increases the risk of kidney function decline, two studies show.

"There are currently limited data on the role of diet in kidney disease," researcher Dr. Julie Lin, of Brigham and Women's Hospital in Boston, said in a news release. "While more study is needed, our research suggests that higher sodium and artificially sweetened soda intake are associated with greater rate of decline in kidney function."

The first study looked at diet and kidney function decline in more than 3,000 women enrolled in the national Nurses' Health Study. The researchers found that "in women with well-preserved kidney function, higher dietary sodium intake was associated with greater kidney function decline, which is consistent with experimental animal data that high sodium intake promotes progressive kidney disease."

The second study looked at the association between sugar- and artificially-sweetened beverages and kidney function decline in the same group of women. The researchers found an association between two or more servings per day of artificially sweetened soda and a two-fold increased risk of faster kidney function decline. There was no connection between sugar-sweetened beverages and kidney function decline.

The association between artificially sweetened beverages and kidney function decline persisted after Lin and colleague Dr. Gary Curhan accounted for other factors, such as age, obesity, high blood pressure, diabetes, smoking, physical activity, caloric intake and cardiovascular disease.

Further study is needed to better understand how artificial sweeteners influence kidney function decline, the researchers said.

The studies were to be presented this week at the annual meeting of the American Society of Nephrology, in San Diego.

More information

The U.S. National Kidney Disease Education Program offers tips on how to keep your kidneys healthy.

SOURCE: American Society of Nephrology, news release, Oct. 31, 2009