Association of Plant-Based Protein Intake with Cognitive Function in Adults with CKD

BACKGROUND
Patients with chronic kidney disease (CKD) have accelerated cardiovascular and cognitive aging when compared to the non-CKD population. This cognitive decline contributes to excessive rates of physical and functional decline, reduced quality of life, and mortality in the CKD population. Mediterranean diets, a plant-forward diet, have been associated with positive cognitive performance in the general non-CKD population and with some beneficial outcomes in CKD. However, it is still unclear whether plant-based diets are associated with cognitive decline in patients with CKD.


METHODS
Using the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-14 data, we conducted a secondary analysis evaluating the relationship of plant-based and unprocessed plant protein with cognitive outcomes measures in eligible participants aged 60 years and older. All data was extracted from the available NHANES demographic, questionnaire, examination, and laboratory data. CKD was calculated and defined in participants as urine albumin to creatinine ratio ≥30mg/g and/or estimated glomerular filtration rate (eGFR) <60 mL/min). In incremental models, we adjusted for total energy intake, age, sex, race/ethnicity, body mass index (BMI), total energy intake, diabetes, hypertension, education, smoking, and alcohol.


RESULTS
Higher plant-based protein above median dietary intakes were significantly associated with higher executive function scores in participants with CKD (p<0.05). For all subjects and in those with CKD, plant-based protein was significantly associated (p<0.05) with higher composite cognitive scores in nearly all statistical models. Higher unprocessed plant protein was significantly associated (p<0.05) with higher composite cognitive scores in all categorical models.


CONCLUSIONS
Higher plant protein intake was a significant predictor of certain individual and composite cognitive score measures within the general and in the CKD population. Future interventional trials are needed to determine if increasing plant-based protein intake improves measures of cognition in patients with CKD.

Background: Plant-based eating is of growing interest in management of CKD due to several reasons, including the proposed lower P bioavailability from plant sources.However, few data are available on the P content of emerging plant-based products.In this study, we aimed to quantify P in several popular food categories of plant-based foods (soy or other pulse-based) and compared to their animal protein counterparts.Our results for plant-based dairy and ground beef alternatives were presented at the National Kidney Foundation Spring Clinical Meeting 2022 and overall showed that P content and P-to-protein ratio were lower in soy-compared to pulse-based products, and soy products were comparable to their animal protein counterparts.
Methods: Here, we present results for plant-based chicken/turkey, sausage/bacon, yogurt/cheese, and other popular soy/pulse products.Products were prepared according to package directions, freeze-dried, ashed and analyzed for P content using MP-AES.
Results: Analyzed P content ranged from 116-196 mg P/100g, 80-293 mg P/100g, and 5-346 mg P/100g for plant-based chicken/turkey, bacon/sausage, and yogurt/cheese products, respectively.For comparison, P content from animal sources in the categories of chicken/turkey, bacon/sausage, and yogurt/cheese ranged from 125-273 mg P/100g, 122-237 mg P/100g, and 105-1223 mg P/100g.Analyzed P content of other soy products (i.e., tofu, tempeh, etc.) ranged from 145-571 mg P/100g and of other pulse products (i.e., chickpea, green lentils, etc.) ranged from 52-166 mg P/100g.Nine of the 40 products analyzed had least one inorganic phosphate additive listed on the label.Total P content of plant-based chicken/turkey alternatives was lowest in pulse-based products, but the P-to-protein ratio was lowest in a soy-based chicken product (3.8 mg/g).Total P content of soy-based cheese products was lower than pulse-or animal-based.However, these soybased cheeses contained no protein, and animal-and pulse-based cheese products had the highest P-to-protein ratios of all food studied, 85.6 mg/g and 103.6 mg/g.
Conclusions: These data show the wide variation in P content and P-to-protein ratio of both plant-based products and their animal-based counterparts.Further quantification and reporting of P content in emerging plant-based products is needed for appropriate recommendations for patients with CKD.
Results: Therapeutic strategies to control Pi-responsive factors were generally as expected with LaC reducing HPD-induced increase in FGF23 and CNC lowering PTH in response to HPD.VitD did not produce an effect and surprisingly Zol somewhat exacerbated response to HPD.Though some strategies controlled systemic, high Pirelated effects, all were generally ineffective at blunting bone loss-except Zol.Changes in kidney-related gene expression-i.e.Klotho, Pi transporters, Lipocalin-2-were influenced by dietary Pi and at least partially corrected with Pi-normalizing strategies.Reducing Pi consumption (LPD) lowered systemic Pi factors and improved bone volume over NPD.
Conclusions: Though individually existing, clinically used therapies are generally effective at correcting some aspects of systemic phosphate dysbiosis in mice, they generally do not correct negative consequences on bone volume.This suggests that the negative health consequences of dysregulated phosphate homeostasis, even in the context of normal renal function, are multifactorial and cannot be fully alleviated with existing clinically used therapies.
Funding: Veterans Affairs Support
Background: Several observational studies reported on a U-shaped association between sodium intake and mortality, which raises questions about the safety of low sodium intake and hampers widespread acceptance of public health campaigns and dietary guidelines.We investigated whether concomitant low protein intake explained the lower part of this U-shaped association between sodium intake and all-cause mortality.
Methods: We investigated the associations between sodium intake (24 h sodium excretion) and all-cause mortality, including the interaction with protein intake (Maroni formula), using multivariable Cox regression in a gender and socioeconomic status balanced Lifelines cohort.
Results: A total of 1603 individuals aged between 60 and 75 years was included.After a median follow-up of 8.9 years, 125 (7.8%) deaths occurred.Both the highest (Q4, >4.7 g/day; HR 1.74 [95%CI 1.03-2.95])and the lowest quartile of sodium intake (Q1, 0.7-2.8g/day; 2.05 [1.16-3.62];p=0.01) were associated with increased risk of allcause mortality compared with the third quartile of sodium intake (Q3, 3.6-4.7 g/day), independent of potential confounders.A significant interaction with protein intake (P-interaction=0.006)was found, with the increased risk of low sodium intake being reversed to reduced risk by concomitant high protein intake, while the increased risk was magnified by concomitant low protein intake (see figure 1).
Conclusions: We found that both high and low levels of sodium intake were associated with increased all-cause mortality.However, higher protein intake annihilated the excess mortality observed in subjects on low sodium intake.A joint low intake of sodium and protein is associated with a particularly high mortality risk, allegedly due to a poor nutritional status.This backs up guidelines advocating to lower sodium intake while also highlighting the importance of recognizing overall nutritional status.

Background:
Dietary inorganic phosphorus (Pi) regulation is crucial for treating CKD patients as excess serum Pi can lead to comorbidities.Studies show high +Pi may negatively impact those with clinically normal renal function via partly understood mechanisms like increased Pi-responsive factors (PTH, osteopontin [OPN], FGF23), kidney damage, and decreased bone volume.Clinicians commonly administer Lanthanum Carbonate (LaC) Pi-binder to reduce serum Pi, Vitamin D (VitD) to increase bone strength, Cinacalcet (CNC) to suppress PTH, and Zoledronate (Zol) to prevent bone loss.Our study investigates these pharmacologic strategies compared to a low Pi diet to reduce excess Pi's negative health consequences.

Therapeutic Strategies for Reversing the Negative Health Effects of a High Phosphate Diet in Mice
Uma D. Alappan, 1 Jamie Arnst, 1 Manjula Viggeswarapu, 2 George R. Beck. 1,21 Emory University School of Medicine, Atlanta, GA; 2 VA Medical Center Atlanta, Decatur, GA.