Special Diets

• By Suzanne Dixon, MPH, MS, RD

DASH Away from Kidney Stones

While rarely life threatening, kidney stones can cause excruciating pain—which is why most people who’ve had them will do just about anything to avoid repeating the experience. Fortunately, something as simple as what you put in your mouth can have a big impact on your risk of kidney stones.

Eating more vegetables, fruit, and low-fat dairy along with eating less salt (sodium) and foods of animal origin changes your chemistry

Deconstructing the DASH diet

Health experts have noted that the DASH diet can lower kidney stone risk. DASH, which stands for Dietary Approaches to Stop Hypertension, is a diet rich in vegetables, fruit, and low-fat dairy, and low in sodium. To further study this connection, researchers collected diet information from 3,426 people with and without a history of kidney stones. Participants were classified based on how closely they followed the DASH diet. Urine samples were analyzed for levels of substances that can affect kidney stone formation.

People who followed the DASH diet most closely secreted significantly more calcium, oxalate, citrate, and total urine volume compared with people who did not follow the diet. The DASH diet followers also had higher urine levels of potassium, magnesium, and phosphate, higher urine pH (in other words, less acidity), and lower relative supersaturation of calcium oxalate and uric acid. All of these urinary measures indicate a lower risk of forming kidney stones, and the results applied to people with and without a history of kidney stones.

Health experts know the DASH diet is associated with lower kidney stone risk, and this study demonstrates how. Eating more vegetables, fruit, and low-fat dairy along with eating less salt (sodium) and foods of animal origin changes urine chemistry. And the altered urine chemistry makes kidney stone formation less likely.

Kicking kidney stones to the curb

DASH your way to healthy kidneys with the following tips:

• Build a DASH-friendly diet by filling two-third of your plate with vegetables and fruit.
• Eat plenty of nuts, seeds, and legumes (beans and peas), also staples of a DASH-friendly eating plan.
• Make all of your grains whole grains.
• Enjoy 2 to 3 servings per day of low-fat dairy, such as skim milk and low-fat yogurt.
• Include no more than one serving per day of lean meat, poultry, and fish.
• Avoid high-fat meats and high-fat diary, such as cheese, butter, cream, and ice cream.
• Skip the salt shaker and avoid high-sodium processed foods such as crackers, chips, sauces, and dressings.
• Flavor your foods with herbs and spices such as oregano, cumin, turmeric, basil, fresh ground pepper, dill, coriander, sage, and thyme to punch up flavor without the salt.
• Drink water all day, every day; aim for a minimum of 64 ounces per day.

(Clin J Am Soc Nephrol; E-Pub Ahead of Print September 16, 2010; The DASH Diet Eating Plan, available at: www.dashdiet.org)