Inadequate Awareness among Chronic Kidney Disease Patients Regarding Food and Drinks Containing Artificially Added Phosphate

Abstract

Hyperphosphatemia is an important determinant of morbidity and mortality in patients with chronic kidney disease (CKD). Patients with CKD are advised to consume a low phosphate diet and are often prescribed phosphate-lowering drug therapy. However, commercially processed food and drinks often contain phosphate compounds, but the phosphate level is not usually provided in the ingredient list, which makes it difficult for CKD patients to choose a correct diet. We conducted a survey of the awareness of food/beverages containing artificially added phosphate among CKD patients undergoing hemodialysis. The subjects were 153 patients (77 males and 76 females; average age 56±11 years) who were randomly selected from the Dialysis Center of Hirosaki City, Japan. The subjects were provided with a list of questions. The survey results showed that 93% of the subjects were aware of the presence of high sugar content in soda, whereas only 25% were aware of the presence of phosphate (phosphoric acid) in such drinks. Despite 78% of the subjects being aware of the detrimental effects of consumption of a high phosphate diet, 43% drank at least 1 to 5 cans of soda per week and about 17% consumed “fast food” once each week. We also assessed the immediate effects of high-phosphate containing carbonated soda consumption by determining urinary calcium, phosphate, protein and sugar contents in overnight fasted healthy volunteers (n = 55; average age 20.7±0.3 years old, 20 males and 35 females). Significantly higher urinary calcium (adjusted using urinary creatinine) excretion was found 2 h after consuming 350 ml of carbonated soda compared to the fasting baseline level (0.15±0.01 vs. 0.09±0.01, p = 0.001). Our survey results suggest that CKD patients undergoing hemodialysis are not adequately aware of the hidden source of phosphate in their diet, and emphasize the need for educational initiatives to raise awareness of this issue among CKD patients.

Dysregulation of phosphate metabolism and conditions associated with phosphate toxicity

“…3,43,45,79 Recent survey results highlight that even future medical professionals and CKD patients undergoing hemodialysis are not adequately aware of the hidden source of phosphate in their diet, and emphasize the need for educational initiatives to raise awareness of the risk posed by dietary items with hidden phosphate ingredients. 100,101 Taking into account human and animal observations, maintaining phosphate balance through adequate dietary intake appears to be important for a healthy life and for longevity. In addition, phosphate imbalance owing to bone-kidney miscommunication can induce serious debilitating complications.…”

What is the Level of Awareness About the Foods Containing Inorganic Phosphorus in Patients with Chronic Renal Failure?

“…The survey was adapted from the study by Shutto et al The patients were surveyed before and after education on nutrition, twice in the course of one year. 3 Survey 1 was conducted in January 2016, while survey 2 was conducted in January 2017.…”

“…of dietary phosphorus intake, and treatment using phosphorus-lowering drugs are the essential measures. [1][2][3] In a patient undergoing regular hemodialysis (HD) treatment three times weekly, the amount of phosphorus removed by dialysis is approximately 3.000 mg/week. 5 However, HD alone is not enough to yield a negative phosphorus balance.…”

“…1 The added inorganic phosphorus is often omitted on the product nutrition facts/labels. 1,3 As a result of improper dietary preferences, the daily phosphorus intake of CRF patients can be increased. 1 Thus, we should educate our patients on reading nutrition labels.…”

Phosphate toxicity: a stealth biochemical stress factor?

“…Although measuring extracellular serum phosphate is the gold standard to estimate the overall phosphate status of the body, the amount of intracellular phosphate distribution or phosphate storage or the amount of phosphate uptake is not taken into consideration in such traditional methods of serum measurement. Moreover, lack of public awareness of getting too much dietary phosphorus [13,14], which might not always be reflected by serum phosphate levels, is gradually becoming a public health concern as dietary phosphate burden from consumption of an unhealthy diet is linked to various non-communicable diseases and eventual mortality [15]. …”