International

Renal Anaemia in the news

Avoiding phosphorus-containing food additives benefits kidney patients

• 11 February 2009
• Reuters Health

NEW YORK (Reuters Health) - Educating patients with end-stage renal disease (ESRD) to avoid processed and fast foods prepared with phosphorus-containing additives results in clinically significant improvements in serum phosphorus levels, report investigators at Case Western Reserve University in Cleveland, Ohio.

Hyperphosphatemia associated with impaired renal excretion of phosphorus increases mortality and contributes to atherosclerosis and bone disease, principal investigator Dr. Ashwini R. Sehgal and colleagues explain in the Journal of the American Medical Association for February 11.

Patients with ESRD are taught to limit intake of foods naturally high in phosphorus, such as meats, dairy products, whole grains, and nuts. However, food additives are another significant source of phosphorus. Phosphate salts are used as preservatives, stabilizers and flavor enhancers in prepared and fast foods.

To see if altering consumption of additives would reduce serum phosphorus levels, Dr. Sehgal's team conducted a cluster randomized trial at 14 hemodialysis facilities, involving 279 patients with elevated serum phosphorus.

The intervention group subjects (n = 145) were given lists of common phosphorus-containing additives to check against food items at grocery stores and fast food menu items with high phosphorus content and healthy alternatives. The control group (n = 134) received standard care.

At baseline, mean serum phosphorus level was 7.2 mg/dL in the intervention group and 7.1 mg/dL in the control group. At the end of 3 months, serum phosphorus levels had declined significantly more in the intervention group (-1.0 vs -0.4 mg/dL, p = 0.03).

"The 0.6-mg/dL larger decline ... corresponds to a 5% to 15% reduction in relative mortality risk in observational studies," Dr. Sehgal and associates write.

The authors recommend mandating phosphorus content on food labels, and creating incentives for marketing low-phosphorus products to improve the health of patients with kidney disease, and the general public as well.

JAMA 2009;301:629-635.