Cutting Phosphorus Additives Reduces Hyperphosphatemia
In a study, 69.7% of intervention patients attained serum phosphorus levels below 5.5 mg/dL, compared with just 18.5% of control patients.
Replacing processed foods containing phosphorus additives with homemade and store-bought alternatives improves phosphorus control without compromising nutritional status, a small study confirms.
“This study shows the importance of using individualized nutritional counseling among ESRD patients in combination with phosphate binders to reduce serum phosphorus levels,” Margareth Lage Leite de Fornasari, RD, PhD, and Yvoty Alves dos Santos Sens, MD, PhD, of São Paulo School of Medical Sciences in Brazil, said in the Journal of Renal Nutrition.
The investigators randomly assigned 134 conventional hemodialysis (HD) patients with hyperphosphatemia (serum phosphorus above 5.5 mg/dL) to either an intervention group taught to replace food additives or to a control group dispensed usual advice on reducing dietary phosphorus as part of a renal diet. Both groups completed 3-day dietary recalls and food diaries at the beginning and end of the 3-month study that included a HD day, a nondialysis day, and a weekend day.
The researchers estimated patients' phosphorus additive intake using information on the labels of foods they commonly consumed. According to 1 estimate, additives account for more than 30% of dietary phosphorus intake; and an estimated 90% of inorganic phosphorus is absorbed. Americans' average daily intake of dietary phosphorus is nearly double the recommended limit. Phosphate binder and vitamin D therapies were kept the same during the study. Both groups had similar serum phosphorus levels, nutritional status, and energy intake at the beginning of the study.
Patients in the intervention group additionally received personalized counseling on substituting foods with phosphorus additives with similar items without additives and were given recipes. Individual advice was reinforced throughout the study.
After 3 months, serum phosphorus levels fell in the intervention group from 7.2 to 5.0 mg/dL, but changed little in the control group. A total of 69.7% of intervention patients attained serum phosphorus below 5.5 mg/dL compared with only 18.5% of control participants.
All patients maintained their nutritional status, energy intake, protein intake, and normalized protein nitrogen appearance (a more accurate protein measure) from baseline to the study's end. Although intervention patients replaced phosphorus-containing food additives with similar foods without additives, their nutritional status was not compromised. Average body mass index remained within Kidney Disease: Improving Global Outcomes' (KDIGO) parameters, for example.
1. 1. de Fornasari MLL and dos Santos Sens YA, MD, PhD. Replacing Phosphorus-Containing Food Additives With Foods Without Additives Reduces Phosphatemia in End-Stage Renal Disease Patients: A Randomized Clinical Trial. J Renal Nutr. doi: 10.1053/j.jrn.2016.08.009.