Phosphorus Additives and Their Impact on Phosphorus Content in Foods-An Analysis of the USDAs Branded Foods Product Database.

OBJECTIVES: The frequency of phosphate additives reported in the United States Department of Agriculture Branded Foods Product Database and how these additives impact phosphate content is unknown. METHODS: All products included in the Branded Foods Product Database reporting phosphorus content were reviewed for presence of phosphate salts and/or lecithin additives. RESULTS: Phosphorus content information was available for 3,466 (1.45%) food items, of these 1791 (51.6%) contained additives. Median phosphorus content was lowest in products with lecithin only compared to products without phosphorus additives (86 [54-200] vs. 145 [77-351] mg per 100 g, P < .01), which was not different from products with phosphate salts (176 [101-276] mg per 100 g, P = .22) or products with both phosphate salts and lecithin (161 [99-285] mg per 100 g, P = 1.00). The impact of a phosphorus salt on phosphorus content (mg per 100) was explored among ultra-processed products grouped by similar phosphorus contents. The phosphorus content of in in nondairy alternatives, dairy, plant proteins, and grains were significantly higher when the product contained a phosphate salt compared to products without a phosphate salt. For all products phosphorus and potassium content were correlated, but the relationship was stronger for when a potassium phosphate additive was present compared to absent (rho = 0.81 vs. 0.53, P < .05). Similar patterns were seen for sodium, calcium, and iron with stronger correlations with phosphate content for products with additives than those without (calcium phosphate: rho = 0.47 vs. 0.32; iron phosphate: rho = 0.47 vs. 0.33; sodium phosphate: rho = 0.45 vs. 0.07. All P < .05). The relationship between phosphate and sodium for products without phosphate additives was weak. CONCLUSIONS: Lecithin may not be associated with increased phosphorus content. Calcium, potassium, sodium, and iron phosphorus salts appear to be associated with increases in the composite mineral and phosphorus content, with the strongest correlation between potassium and phosphorus content.

Currently Available Handouts for Low Phosphorus Diets in Chronic Kidney Disease Continue to Restrict Plant Proteins and Minimally Processed Dairy Products.

OBJECTIVES: The 2020 Kidney Disease Outcome Quality Initiative guidelines recommend adjusting phosphorus intake to achieve and maintain normal serum phosphorus levels for adults living with chronic kidney disease. These guidelines also recommend considering the dietary source of phosphorus as different sources have different bioavailability; however, phosphorus food lists are not provided. Therefore, the aim of this study is to investigate the current teaching materials in Canada regarding low phosphorus diet. DESIGN AND METHODS: Using a geographical approach, websites from each province and territories' government, health, and renal programs (where applicable) were reviewed for resources on dietary phosphorus restriction in chronic kidney disease. All publicly available handouts/booklets/printable webpages were obtained and reviewed for recommendations on how to implement a low phosphorus diet. RESULTS: Sixty-one resources in total met inclusion criteria (52 handouts from health agencies in 6 provinces and 9 handouts from the Kidney Foundation of Canada). Items with minimal nutrition value, such as cola, beer and cocoa, chocolate, and baking powder, were the most commonly restricted with 84% (51/61) resources making this recommendation. Plant proteins and minimally processed dairy were restricted in 80% (49/61) of resources. Processed animal meat was recommended to be restricted in 70% (43/61) of resources and whole grains in 65% (40/61). Sixty-three percent of the handouts (39/61) discuss avoiding phosphorus additives. CONCLUSIONS: Many resources restrict items with minimal nutrition value to lower phosphorus intake; however, plant foods, including plant proteins and whole grains, continue to be restricted in the majority of resources, despite having lower bioavailability. The 2020 Kidney Disease Outcome Quality Initiative guidelines recommend considering bioavailability of phosphorus source when implementing low phosphorus diets; current handouts in Canada would likely benefit from review.

Soaking to Reduce Potassium and Phosphorus Content of Foods.

OBJECTIVES: To achieve and maintain normal serum potassium and phosphorus levels reducing potassium and phosphorus intake is frequently recommended for adults living with chronic kidney disease. Exploring food preparation methods to reduce potassium and phosphorus content appears warranted. The study aim is to determine the impact of soaking foods in hot water on potassium and phosphorus content in a variety of plant- and animal-based foods. METHODS: Twenty foods were selected that are common staples in Brazilian diet patterns. Food was soaked for 5-10 minutes in deionized water that had been brought to a boil and then removed from heat using a 5-part water to 1-part sample ratio. The potassium content was determined by flame photometry. The phosphorus content was determined by visible ultraviolet spectrophotometry. RESULTS: Soaking foods resulted in a reduction in potassium and phosphorus. Potassium reduction in beef, green leafy vegetables, and grains was 40-49%; in chicken, fish, and nonleafy vegetables 30-39%; and tubers 10-20%. Phosphorus reduction in grains and beans was 30-39%; in nonleafy vegetables 20-29%; and beef, chicken, and fish 10-20%. CONCLUSIONS: Soaking foods in hot water for 5-10 minutes reduces potassium and phosphorus content. Using this technique to prepare foods may be a more acceptable alternative to longer demineralization periods making it easier for adults living with chronic kidney disease to follow diet recommendations.

Sarcopenia and sarcopenic obesity in chronic kidney disease: update on prevalence, outcomes, risk factors and nutrition treatment.

PURPOSE OF REVIEW: This review summarizes literature from the last 18 months reporting on sarcopenia (or its components) in chronic kidney disease (CKD). RECENT FINDINGS: The prevalence of sarcopenia in CKD is reported to be 5-62.5%, with higher rates observed later in the disease. Sarcopenic obesity rates are reported to be 2-23%. Sarcopenia in CKD is associated with increased risk of mortality, cardiovascular disease and vascular calcification. Risk factors include kidney disease itself and the impacts of CKD on lifestyle (reduced physical activity, diet changes). In earlier stages of CKD, if the risks from sarcopenia outweigh the risk of reaching end-stage renal disease, ensuring adequate energy intake combined with modest protein liberalization and physical activity may be indicated. Protein intakes above 1.3 g/kg of body weight per day should be avoided. For dialysis patients, interventions that provide a combination of carbohydrate, protein and fat appear more effective than those that provide protein alone, though it may take as long as 48 weeks for detectable changes in muscle mass. SUMMARY: Sarcopenia is prevalent in CKD as kidney disease significantly impacts muscle mass and function. Nutrition interventions can improve components of sarcopenia, with an emphasis on adequate energy and protein.

Comparison of diet quality tools to assess nutritional adequacy for adults living with kidney disease.

There is no specific diet quality tool recommended for adults living with chronic kidney disease (CKD). Identifying how diet quality tools assess nutritional adequacy and correlate with potassium and phosphorus (nutrients of interest in CKD) is warranted. Our aim was to compare Mediterranean Diet Scores (MDS), Healthy Eating Index (HEI), and Healthy Food Diversity (HFD) to determine their correlation with nutrient intake in adults living with diabetes and CKD. Using data from a longitudinal study of 50 participants with diabetes and CKD, diet quality was assessed at baseline and 1 or more times at annual visits up to 5 years (complete diet records n = 178). Diet quality was investigated for correlation with nutrient intake. Compared with HEI and HFD, MDS was poorly correlated with nutrient intake (all r values <0.40). HFD and HEI were moderately correlated with potassium (r = 0.66, P < 0.01 and r = 0.57, P < 0.01, respectively). HEI was weakly correlated with phosphorus (r = 0.365, P < 0.01). MDS recommends moderation of dairy and meat, this may have specific benefits for CKD as these are both sources of phosphorus, as such high MDS were associated with lower phosphorus intake. This study suggests that development of a renal specific diet quality assessment tool may be useful; however, further studies are needed.

Potassium content of the American food supply and implications for the management of hyperkalemia in dialysis: An analysis of the Branded Product Database.

Ultraprocessed foods can be a source of potassium additives. Excess potassium consumption can lead to hyperkalemia. How frequently potassium additives are found in the food supply and how they impact potassium content is not well documented. Using the Branded Product Database, ingredient lists were searched for "potassium" to identify products containing additives. For products listing potassium content, accuracy of potassium content reporting and how potassium content differed with additive use was also assessed. A total of 239,089 products were included, 35,102 (14.7%) contained potassium additives, and 13,685 (5.7%) provided potassium content. Potassium additives were most commonly found in dairy products, supplements, and mixed foods (at 37%, 34%, and 28%, respectively). Potassium additives in mixed foods and vegetables and fruits were associated with 71% and 28% more potassium per serving, respectively (p < 0.01). Potassium content increased by 1874 mg (66%) when a 1-day sample menu compared foods with and without additives. Potassium content of foods with and without additives is not well documented. Potassium additives are prevalent and can be associated with increased potassium content. However, more information is needed to better understand how different additives used in different foods change potassium content.

The Impact of Protein Type on Phosphorus Intake, Serum Phosphate Concentrations, and Nutrition Status in Adults with Chronic Kidney Disease: A Critical Review.

Lower phosphorus intake to prevent hyperphosphatemia for those with chronic kidney disease (CKD) is often recommended. Plant proteins are frequently restricted for their high phosphorus content despite having lower bioavailability. To summarize the evidence on protein type and dietary phosphorus intake, serum phosphate concentrations, and nutritional adequacy in adults with CKD, a search in MEDLINE via Ovid was conducted. Citation lists were reviewed to identify any additional articles. Sixteen articles were included-7 intervention (n = 290) and 9 observational (n = 4933). All intervention trials reported high-plant-protein diets provided adequate protein and adhered to low phosphorus diet guidelines. All intervention trials reported higher plant-protein intake was associated with lower serum phosphate; however, only 2 achieved statistical significance. For observational studies, 2 reported that higher proportions of plant to animal protein resulted in lower phosphorus intake but equivalent serum phosphate concentrations. Two reported that plant protein and animal protein had equivalent correlation values to phosphorus intake and no correlation to serum phosphate concentrations. One trial reported lower total phosphorus and protein intake among those who consumed more plant proteins but did not examine serum concentrations. Four reported lower serum phosphate concentrations among those who consumed more plant proteins but did not report dietary phosphorus intake. Of the observational studies that reported on protein intake, all reported lower protein intake among those with higher versus lower plant-protein intake. BMI tended to be lower among those consuming more plant protein. There was not a consistent relation between protein type and albumin concentrations. Routine restriction of plant-protein foods to prevent hyperphosphatemia in CKD would likely benefit from re-evaluation, as evidence does not suggest that higher plant-protein intake leads to higher serum phosphate concentrations or worse nutritional status, although longer-duration intervention trials with larger sample sizes appear to be warranted.