Kidney Diet Tips

What does baking soda have to do with kidney disease?

iStock_000004059651BiscuitBaking soda, also known as sodium bicarbonate, is a common ingredient in quick breads, cakes and cookies.  My grandmother added a little as the final ingredient to her famous peanut brittle candy.   My dad drank baking soda-spiked water as a treatment for indigestion.  Search any refrigerator in an American household and you’re likely to find a box of Arm & Hammer® baking soda to absorb and eliminate food odors.

One of the headliners in this week’s Renal Business Today’s eNewsletter is fizzy tablet“Baking Soda Slows Progression of Chronic Kidney Disease”.  The article sites a Royal London Hospital based research study published online in the Journal of the American Society of Nephrology.  A group of patients with advance chronic kidney disease (CKD) were given a daily sodium bicarbonate tablet.  Decline in kidney function for this group was greatly decreased compared to the group who did not receive the sodium bicarbonate.  Additional studies are required before recommending this treatment but there’s hope in knowing this simple treatment may help your kidneys last longer.

In advanced kidney disease, accumulation of waste products such as sulfates, phosphates and uric acid cause an imbalance in the blood pH, resulting in a condition called metabolic acidosis.  Meta what???  It’s a medical term that means there’s too much acid in the blood.  It’s detected by measuring CO2 levels—normal is 22 mmol/L; as levels go lower, acidosis increases.   Normally to restore things to normal you breathe faster to get rid of CO2 and your kidneys clear more acid through the urine while making more bicarbonate.   With kidney failure, this doesn’t happen.  In the above mentioned study, the sodium bicarbonate tablets helped by increasing bicarbonate levels to restore normal blood pH.

There’s a nutritional benefit to correcting metabolic acidosis.  When too much acid builds up in the blood, proteins in the body break down, causing loss of protein stores from muscles, organs and tissues.  Chronic metabolic acidosis can also cause loss of bone minerals and contribute to bone disease.   These problems have been detected and studied in people with CKD stages 3, 4 and 5.

What can you do? Learn more about metabolic acidosis and how it is related to kidney disease.  Your doctor monitors your blood work and can let you know if your CO2 level is normal or if you are at risk for acidosis.   If you are on dialysis, your renal dietitian can also answer questions about your CO2 level.   Self-prescribed treatment with sodium bicarbonate is not recommended as any therapy for kidney patients must be closely monitored.

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Sara Colman, RD, CDE

Sara is a renal dietitian with over 20 years experience working with people with diabetes and kidney disease. She is co-author of the popular kidney cookbook "Cooking for David: A Culinary Dialysis Cookbook". Sara is currently the Manager of Kidney Care Nutrition for DaVita. She analyzes recipes and creates content, resources and tools for the kidney community. In her spare time Sara loves to spend time with her young grandson, including fun times together in her kitchen.