Short-Term Effects of a Therapeutic Diet on Biochemical Parameters in Hemodialysis Patients: A Randomized Crossover Trial.

OBJECTIVE: Although unhealthy diets exacerbate nutritional and metabolic derangements in patients with end-stage kidney disease (ESKD), how therapeutic diets that possess a variety of different dietary strategies acutely modify diverse biochemical parameters related to cardiovascular disease remains underexplored. METHODS: Thirty-three adults with end-stage kidney disease undergoing thrice-weekly hemodialysis participated in a randomized crossover trial comparing a therapeutic diet with their usual diets for 7 days, separated by a 4-week washout period. The therapeutic diet was characterized by adequate calorie and protein amounts, natural food ingredients with a low phosphorus-to-protein ratio, higher portions of plant-based food, and high fiber content. The primary outcome measure was the mean difference in the change-from-baseline intact fibroblast growth factor 23 (FGF23) level between the 2 diets. The other outcomes of interest included changes in mineral parameters, uremic toxins, and high-sensitivity C-reactive protein (hs-CRP) levels. RESULTS: Compared with the usual diet, the therapeutic diet lowered intact FGF23 levels (P = .001), decreased serum phosphate levels (P < .001), reduced intact parathyroid hormone (PTH) levels (P = .003), lowered C-terminal FGF23 levels (P = .03), increased serum calcium levels (P = .01), and tended to lower total indoxyl sulfate levels (P = .07) but had no significant effect on hs-CRP levels. Among these changes, reduction in serum phosphate level achieved in 2 days, modifications of intact PTH and calcium levels in 5 days, and reductions in intact and C-terminal FGF23 levels in 7 days of therapeutic diet intervention. CONCLUSION: Within the 1-week intervention period, the dialysis-specific therapeutic diet rapidly reversed mineral abnormalities and tended to decrease total indoxyl sulfate levels in patients undergoing hemodialysis but had no effect on inflammation. Future studies to assess the long-term effects of such therapeutic diets are recommended.

Boiling for 15 minutes improves nutrient profiles in fishes included in the diets of dialysis patients.

INTRODUCTION: Little is known about the effects of boiling on nutrient levels in fishes that have a relatively high phosphorus-to-protein ratio (PPR), which are important sources of omega-3 polyunsaturated fatty acids. We hypothesized that the beneficial effects of boiling for a shorter duration (15 min) on nutrient contents in fishes were similar to those of boiling for a longer duration (30 min), which has been shown to decrease the PPR in meat. METHODS: The protein, fat, and phosphorus contents and the PPR of three cooked fish species and their corresponding fish broths were chemically analyzed. The effects of boiling on changes in protein, fat, phosphorus, and the PPR was examined by comparing fish that were prepared with usual cooking methods (no boiling), boiled for 15 min, and boiled for 30 min. The nutrients in fish broths that were boiled for 15 min were also compared with those boiled for 30 min. FINDINGS: There were no significant differences in the changes in phosphorus, PPR, protein, and fat content in fish and fish broths prepared with the two boiling methods. In the fish boiled for 15 min, the phosphorus content was 24% lower (p = 0.001), and the PPR was 20% lower (p = 0.04) than those in nonboiled fish. Additionally, boiling for 30 min reduced the phosphorus content by 31% (p = 0.001), and the PPR by 27% (p = 0.04) compared to nonboiled fish, but the protein and fat contents were unchanged after both 15 and 30 min of boiling. DISCUSSION: The 15- and 30-min boiling methods resulted in a similar reduction in phosphorus and the PPR in fish, with minimal effects on protein and fat. A shorter duration of boiling is recommended to achieve better nutrient profiles in fishes consumed by dialysis patients.