A diet designed to prevent high blood pressure might also help ward off kidney stones, a new study suggests.
Participants who followed the DASH diet (Dietary Approaches to Stop Hypertension), which is high in fruits, vegetables, nuts and legumes, dairy products and whole grains, and is low in sweetened beverages and red and processed meats, excreted more urine than those who did not follow the diet, despite similar fluid intake.
Kidney stones can form when there is not enough liquid to dissolve the minerals and salts that make up urine.
The urine of DASH dieters contained more citrate, a compound that breaks down calcium stones, than the urine of others in the analysis, according to the researchers. The study also indicated that there may be other important, and perhaps as of yet unidentified, kidney stone inhibitors in dairy products and plants .
The investigators studied urine samples of 3,426 individuals with and without a history of kidney stones over a 24-hour period in the Health Professionals Follow-up Study (HPFS) and the Nurses' Health Studies (NHS) I and II.
The study participants were part of a previous, larger study which found that a DASH-style diet was associated with a generally reduced risk of kidney stone formation.
The researchers speculated that higher urine volumes were, at least in part, a result of the higher amount of water found in the foods eaten as part of the DASH-style diet.
The data suggest that diet could be important for keeping stones from reappearing in people who suffer from them, according to the researchers. Future research, such a trial in which participants are randomly chosen to follow either the DASH diet or a normal diet, will be needed to determine whether the diet does indeed prevent kidney stone recurrence, the researchers said.
The study will be published in upcoming issue of the Clinical Journal of the American Society Nephrology.
The study was conducted by Dr. Eric Taylor, of Brigham and Women's Hospital in Boston, Mass., and colleagues.