Effect of Food Additives on Hyperphosphatemia Among Patients With End-stage Renal Disease

Abstract

NDIVIDUALS WITH MODERATE TOsevere renal disease have an impaired ability to excrete phosphorus. As a result, they tend to develop hyperphosphatemia, especially in settings of high phosphorus intake. Elevated serum phosphorus levels are independently associated with increased mortality and morbidity. For example, serum phosphorus levels greater than the 5.5-mg/dL level recommended by practice guidelines are independently associated with a 20% to 40% increase in mortality risk among patients with end-stage renal disease (ESRD). [1][2][3][4][5][6][7][8][9] In addition, hyperphosphatemia appears to be involved in the development of atherosclerotic heart disease, secondary hyperparathyroidism, and bone disease among renal patients. [10][11][12] High phosphorus intake may also be detrimental for the general public. The dietary phosphorus intake of individuals in the United States has been in-creasing, while intake of calcium has been decreasing. 13 There is evidence to suggest that these intake patterns in-terfere with the normal process of calcium regulation and affect both peak bone mass and rate of bone loss, even See also Patient Page.

Understanding Sources of Dietary Phosphorus in the Treatment of Patients with Chronic Kidney Disease

“…Additional studies, including randomized, controlled trials, should examine whether restriction of nonprotein sources of P is safer and more effective. A recent randomized, controlled trial showed that P intake may be decreased by restricting intake of enhanced food with P-containing additives (37). Although it is possible that this dietary modification did not substantially reduce protein intake, the latter study did not present data on this question (37).…”

“…Because humans do not express the degrading enzyme phytase, the bioavailability of P from plant-derived food is relatively low, usually Ͻ50% (36). Hence, despite the "apparently" higher P content of some plants (see Table 1), the actual result may be a lower rate of intestinal P absorption per gram of plant protein than animalbased protein (37). When healthy humans are given the same amount of dietary P from either animal or plant foods, urinary P excretion is higher with the meat-based diet (38).…”

“…Additives are used in food processing for a variety of reasons, including to extend shelf life, improve color, enhance flavor, and retain moisture (37,42). The presence of inorganic P is often obscured by the use of complex names for the ingredients (43,44).…”

“…Indeed, it is believed that Ͼ90% of inorganic P may be absorbed in the intestinal tract, as opposed to only 40 to 60% of the organic P present in natural foods (51,52). The major public health implication from these considerations is that the P burden from inorganic P-containing food additives is disproportionately high relative to organic P. In the early 1990s, P additives contributed approximately 500 mg/d P to the American diet, whereas today P additives may contribute as much as 1000 mg/d P to the average American diet (37,51,53,54).…”

Association of Dietary Phosphorus Intake and Phosphorus to Protein Ratio with Mortality in Hemodialysis Patients

“…Restriction of dietary intake of phosphorus generally requires some reduction in the allowable protein intake (8) and restricted consumption of highly processed fast and convenience foods (16). However, imposing dietary phosphorus restriction can lead to obligatory reduction in dietary protein intake, which per se is associated with protein-energy wasting (PEW) (17) and increased mortality (8).…”