Patient preference may play bigger role in phosphorous control vs ‘healthy’ food access
A study of patients who received dialysis at centers across the United States revealed no link between neighborhood food environment – including access to “healthy foods” and socioeconomic status – and hyperphosphatemia.
This finding led Vishnu S. Potluri, MD, MPH, of the Perelman School of Medicine at the University of Pennsylvania, and colleagues to suggest factors such as individual food preference, nutritional education and food labeling may have more of an impact on serum phosphorous management.
“Foods rich in phosphorus are prevalent in the American diet,” Potluri and colleagues wrote. “Geographic areas with more poverty often have less availability of low-phosphorus alternatives, including fruits and vegetables. Because of the phosphorus-rich content of many types of food, we hypothesized that restrictions on food availability might affect phosphorus control for patients on dialysis, acknowledging that dietary choices are complex and depend on multiple factors, including gustatory preferences, sociocultural norms and comorbidities such as diabetes, income and nutrition literacy.”
For the study, researchers included 258,510 patients who received chronic hemodialysis between 2005 and 2013 (45% were women; 32% were Black patients; 15% were Hispanic patients).
Using the criteria defined by the CDC and Prevention Modified Retail Food Environment Index to categorize neighborhood availability of healthy food, Potluri and colleagues found patients had a median of 25 “less-healthy” food outlets available to them compared with a median of four “healthy” food outlets.
Despite this, researchers observed no association between living in a neighborhood with increased availability of healthy food and lower phosphorus levels. In addition, neighborhood income did not appear to affect phosphorous levels.
As for factors more closely associated with phosphorous levels, researchers determined patient age and race had an impact.
More specifically, they found older patients had a lower serum phosphorus than younger patients (serum phosphorus was 0.3 mg/dL lower for every 10-year increase in age), while patients who self-identified as Black or Hispanic had slightly lower phosphorous levels than white patients (0.2 mg/dL and 0.1 mg/dL, respectively).
“Understanding a patient’s income, food availability near where they live and their personal preferences can help develop personalized dietary plans to reduce dietary phosphorus intake,” the researchers wrote of their findings. “Future remedies to improve phosphorus control may require addressing these issues, as well as the pervasive problem of inadequate labeling.”
In terms of “inadequate labeling,” Potluri and colleagues highlighted that the FDA does not require food manufacturers to include phosphorous content.
“When the phosphorus content of food is listed on labels, the label can be challenging to interpret or the phosphorus content may be inaccurately stated,” they contended, adding “many patients on chronic dialysis have low health and nutrition literacy and limited income, creating further barriers to selecting meals low in phosphorus.”