DASH Diet May Lower Recurrent Kidney Stone Risk

The Dietary Approaches to Stop Hypertension (DASH) diet might be an effective alternative to the low-oxalate diet for reducing risk of kidney stone recurrence, according to research published in the March issue of the American Journal of Kidney Diseases.

Nazanin Noori, M.D., Ph.D., of the Shahid Beheshti University of Medical Sciences in Tehran, Iran, and colleagues randomly assigned recurrent kidney stone formers to follow the DASH diet (29 participants) or a low-oxalate diet (28 participants). At eight weeks, the researchers assessed changes in urinary calcium oxalate supersaturation and 24-hour urinary composition.

Among the 41 participants who completed the trial (DASH group, 21; low-oxalate group, 20), the researchers observed a trend for increase in urinary oxalate excretion for the DASH group versus the low-oxalate group (point estimate of difference, 9.0 mg/d; 95 percent confidence interval [CI], −1.1 to 19.1 mg/d; P = 0.08).

However, in the DASH group, compared with the low-oxalate group, a trend for calcium oxalate supersaturation to decrease was observed (point estimate of difference, −1.24; 95 percent CI, −2.80 to 0.32; P = 0.08) in association with an increase in magnesium and citrate excretion and urine pH.

"We conclude that the DASH diet could represent a novel strategy worthy of study in the prevention of high urinary calcium oxalate supersaturation, in addition to the conventional low-oxalate diet," the authors write.

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