DASH diet linked to lower kidney stone risk
(Relaxnews) – A diet high in fruits, vegetables, legumes and nuts is believed to reduce the risk of kidney stones in addition to lowering blood pressure, according to a small new study published in the March issue of the National Kidney Foundation’s American Journal of Kidney Diseases. This diet is also moderate in low-fat dairy products and low in meat, refined grains and white sugar.
Researchers compared a low-oxalate diet, which is frequently prescribed for prevention and treatment of kidney stones, to a Dietary Approaches to Stop Hypertension (DASH)-style diet, finding the latter potentially more effective in reducing risk of calcium oxalate kidney stones, the most common type.
Oxalate is found naturally in a number of nutritious foods, including sweet potatoes, kale, rice bran, beets, navy beans, almonds, spinach and rhubarb. The National Kidney Foundation notes that most kidney stones form when oxalate binds to calcium as urine is being produced by the kidneys. New research suggests that rather than eliminating oxalate foods from the diet, eating and drinking calcium and oxalate-rich foods together may be more beneficial. Oxalate and calcium are more likely to bind in the stomach and intestines when eaten together, making it less probable kidney stones will form.
Nazanin Noori, MD, PhD and other researchers studied 41 participants at The Hospital for Sick Children in Toronto over an eight-week period and found those who followed the DASH diet decreased their kidney stone risk by 35%, while those who went the low-oxalate route reduced their risk by 14%.
Levels of calcium, oxalate, citrate, sodium, potassium, magnesium, uric acid, pH and calcium oxalate in urine were studied as kidney stone “risk markers.”
“Most people do not eat single, isolated nutrients, such as oxalate, but rather meals consisting of a variety of foods,” says Noori. “So a practical diet plan for kidney stone prevention should be based on the cumulative effects of foods and the impact overall dietary patterns have on risk for stone formation rather than single nutrients.”