This week one of my online friends sent a question about soy milk versus cow’s milk in the kidney diet. “Which is better for a person with chronic kidney disease?” was prompted when he substituted soy milk for cow’s milk in his favorite Starbuck’s coffee drink. Soy milk is made from soy beans, and any bean product is potentially a food high in potassium and high in phosphorus.
However all products are not created equal. Soy milk brands vary in potassium, phosphorus, calcium and sodium so it is essential to check the nutrition label and ingredients list. The nutrition label might list milligrams of potassium but it is not required. In some cases the label may include phosphorus expressed as a percentage of the Daily Value, which is the percent of a nutrient recommended based on a 2000 calorie healthy diet (5% or less is low and equals 50 mg phosphorus and 20% or more is high and equals 200 mg phosphorus). For people with kidney disease who have high parathyroid hormone levels or high phosphorus levels, the lowest phosphorus-containing milk substitute is best.
Potassium, Phosphorus, Sodium, Calcium and Protein in Soy Milk
Listed below are the nutrient values for an 8 ounce serving (240 ml) of several soy milk brands conpared to cow’s milk.
Soy Dream© unenriched, original or vanilla 240-260 mg Potassium, 100 mg Phosphorus, 140 mg Sodium, 40 mg Calcium, 7 g Protein
Soy Dream©, fortified 240-350 mg Potassium, 250 mg Phosphorus, 140 mg Sodium, 295 mg Calcium, 7 g Protein
Silk© soy milk 300 mg Potassium, Phosphorus not available, 120 mg Sodium, 300 mg Calcium, 7 g Protein
Silk Plus© for bone health 300 mg Potassium, Phosphorus not available, 95 mg Sodium, 400 mg Calcium, 6 g Protein
Silk Plus© omega 3, DHA 350 mg Potassium, Phosphorus not available, 120 mg Sodium, 350 mg Calcium, 7 g Protein
Edensoy© original 440 mg Potassium, 140 mg Phosphorus, 105 mg Sodium, 105 mg Calcium, 11 g Protein
Westsoy Smart Plus© 370 mg Potassium, 250 mg Phosphorus, 90 mg Sodium, 250 mg Calcium, 11 g Protein
Eden Soy© original or vanilla 290-440 mg Potassium 90-140 mg, Phosphorus, 90-105 mg Sodium, 60-80 mg Calcium, 6 g Protein
Eden Soy Extra©, fortified, original or vanilla 290-450 mg Potassium, 100-150 mg Phosphorus, 90-100 mg Sodium, 200 mg Calcium, 9-10 g Protein
Cow’s milk 370-450 mg Potassium, 220-280 mg Phosphorus, 100-145 mg Sodium, 285-350 mg Calcium, 8-10 g Protein
Benefits of soy milk versus cow’s milk for kidney disease
Replacement of animal protein with plant protein like soy in the kidney diet can reduce protein loss in the urine (proteinuria) and may help preserve kidney function for those with chronic kidney disease. This is attributed to phytoestrogens from soy. In addition to soy milk, kidney disease patients can explore other soy products like soy protein powder, nutrition bars with soy, tempeh, tofu and meat analogs made with soy. Work with your renal dietitian to see which of these foods for kidney health fit into your individual renal diet.
For more information on phytoestrogens from soy and kidney disease you may be interested in the article “Protective effects of Dietary Phytoestrogens in Chronic Renal Disease” in the Journal of Renal Nutrition, Vol 11, No 4 (October) 2001: pp 183-193.
Kidney diet resources from DaVita.com