Food additives harmful for kidney patients.

Two hundred seventy-nine patients with end-stage renal disease and hyperphosphatemia were randomly assigned to an intervention group or a control group. The intervention group received education on avoiding foods with phosphorus additives when purchasing groceries or visiting fast-food restaurants. The control group received usual care. After three months, the decline in serum phosphorus levels was 0.6 mg/dl greater in the intervention group than in the control group (p = 0.03).

Comment: Patients with end-stage renal disease have an impaired capacity to excrete phosphorus and are at risk of developing hyperphosphatemia, which can increase morbidity and mortality. Renal patients are therefore advised to restrict intake of high-phosphorus foods (such as meats, dairy products, whole grains, and nuts), and are also treated with phosphate binders. In recent years, phosphorus-containing food additives (primarily in processed and fast foods, particularly meats, cheeses, baked goods, and beverages) have become an important source of dietary phosphorus, contributing up to one-third of total phosphorus intake in the general population. The results of this study suggest that avoiding these foods could improve long-term outcomes in patients with chronic renal failure.

Sullivan C et al. Effect of food additives on hyperphosphatemia among patients with end-stage renal disease: a randomized controlled trial. JAMA. 2009;301:629-635.

by Alan R. Gaby, MD

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