Nutritional Adequacy of Essential Nutrients in Low Protein Animal-Based and Plant-Based Diets in the United States for Chronic Kidney Disease Patients

Achieving High Protein Quality Is a Challenge in Vegan Diets: A Narrative Review

The transition toward plant-based (PB) diets has gained attention as a plausible step toward achieving sustainable and healthy dietary goals. However, the complete elimination of all animal-sourced foods from the diet (ie, a vegan diet) may have nutritional ramifications that warrant close examination. Two such concerns are the adequacy and bioavailability of amino acids (AAs) from plant-sourced foods and the consequences for older vegan populations who have elevated AA requirements. This narrative review describes the challenges of achieving high protein quality from vegan diets. Data were synthesized from peer-reviewed research articles and reviews. Plant-sourced proteins provide poorer distribution of indispensable AAs (IAAs) and have poorer digestibility, partly due to their inherent structural components within the food matrix. The review addresses complexities of combinations of varied plant protein sources and why the inclusion of novel PB alternatives adds uncertainty to the achievement of adequate protein adequacy. Meal distribution patterns of protein and the ensuing physiological impacts deserve further research and are outlined in this review. Particular attention is given to describing the challenges of achieving sufficient protein and IAA intakes by aging populations who choose to follow a vegan diet. This review contributes to the emerging discussions of nutritional risks associated with vegan diets and adds perspective to the current dietary shifts toward PB diets.

Protein Intake and Mortality in Older Adults With Chronic Kidney Disease

Importance

Avoiding high protein intake in older adults with chronic kidney disease (CKD) may reduce the risk of kidney function decline, but whether it can be suboptimal for survival is not well known.

Objective

To estimate the associations of total, animal, and plant protein intake with all-cause mortality in older adults with mild or moderate CKD and compare the results to those of older persons without CKD.

Design, Setting, and Participants

Data from 3 cohorts (Study on Cardiovascular Health, Nutrition and Frailty in Older Adults in Spain 1 and 2 and the Swedish National Study on Aging and Care in Kungsholmen [in Sweden]) composed of community-dwelling adults 60 years or older were used. Participants were recruited between March 2001 and June 2017 and followed up for mortality from December 2021 to January 2024. Those with no information on diet or mortality, with CKD stages 4 or 5, or undergoing kidney replacement therapy and kidney transplant recipients were excluded. Data were originally analyzed from June 2023 to February 2024 and reanalyzed in May 2024.

Exposures

Cumulative protein intake, estimated via validated dietary histories and food frequency questionnaires.

Main Outcomes and Measures

The study outcome was 10-year all-cause mortality, ascertained with national death registers. Chronic kidney disease was ascertained according to estimated glomerular filtration rates, urine albumin excretion, and diagnoses from medical records.

Results

The study sample consisted of 8543 participants and 14 399 observations. Of the 4789 observations with CKD stages 1 to 3, 2726 (56.9%) corresponded to female sex, and mean (SD) age was 78.0 (7.2) years. During the follow-up period, 1468 deaths were recorded. Higher total protein intake was associated with lower mortality among participants with CKD; adjusted hazard ratio (HR) for 1.00 vs 0.80 g/kg/d was 0.88 (95% CI, 0.79-0.98); for 1.20 vs 0.80 g/kg/d, 0.79 (95% CI, 0.66-0.95); and for 1.40 vs 0.80 g/kg/d, 0.73 (95% CI, 0.57-0.92). Associations with mortality were comparable for plant and animal protein (HRs, 0.80 [95% CI, 0.65-0.98] and 0.88 [95% CI, 0.81-0.95] per 0.20-g/kg/d increment, respectively) and for total protein intake in participants younger than 75 years vs 75 years or older (HRs, 0.94 [95% CI, 0.85-1.04] and 0.91 [95% CI, 0.85-0.98] per 0.20-g/kg/d increment in total protein intake, respectively). However, the hazards were lower among participants without CKD than in those with CKD (HRs, 0.85 [95% CI, 0.79-0.92] and 0.92 [95% CI, 0.86-0.98] per 0.20-g/kg/d increment, respectively; P = .02 for interaction).

Conclusions and Relevance

In this multicohort study of older adults, higher intake of total, animal, and plant protein was associated with lower mortality in participants with CKD. Associations were stronger in those without CKD, suggesting that the benefits of proteins may outweigh the downsides in older adults with mild or moderate CKD.

A Therapeutic Approach in the Management of Chronic Kidney Disease: Plant-Based Dietary Models and Associated Parameters

PURPOSE OF REVIEW

Chronic kidney disease is one of the leading causes of death worldwide today. Nutrition and nutrition-related factors have a very important role in both the prevention and management of the disease. Plant-based dietary practices are one of the promising approaches to chronic kidney disease. This review aims to examine the potential benefits and risks of plant-based diet models on symptoms and indices used in diet quality in chronic kidney disease.

RECENT FINDINGS

Recently, a growing body of evidence has shown that, unlike animal-based diets, diets rich in plant-based nutrients may play an active role in the incidence of chronic kidney disease in many ways and the management of common symptoms, such as metabolic acidosis, uremic toxicity, and hyperphosphatemia. Implementation of existing plant-based dietary patterns in patients with chronic kidney disease may increase the efficacy of the diet and improve patients' quality of life by expanding their food choices. While there are concerns about creatine deficiency, dietary adequacy, and accessibility regarding plant-based diets, available information is limited.

Dieta de la Milpa: A Culturally-Concordant Plant-Based Dietary Pattern for Hispanic/Latine People with Chronic Kidney Disease

Chronic kidney disease (CKD) disproportionately affects minorities in the United States, including the Hispanic/Latine population, and is a public health concern in Latin American countries. An emphasis on healthy dietary patterns, including the Mediterranean and the Dietary Approaches to Stop Hypertension (DASH) diets, has been suggested as they are associated with a lower incidence of CKD, slower CKD progression, and lower mortality in kidney failure. However, their applicability may be limited in people from Latin America. The Dieta de la Milpa (Diet of the Cornfield) was recently described as the dietary pattern of choice for people from Mesoamerica (Central Mexico and Central America). This dietary pattern highlights the intake of four plant-based staple foods from this geographical region, corn/maize, common beans, pumpkins/squashes, and chilies, complemented with seasonal and local intake of plant-based foods and a lower intake of animal-based foods, collectively classified into ten food groups. Limited preclinical and clinical studies suggest several health benefits, including cardiometabolic health, but there is currently no data concerning CKD. In this narrative review, we describe and highlight the potential benefits of the Dieta de la Milpa in CKD, including acid-base balance, protein source, potassium and phosphorus management, impact on the gut microbiota, inflammation, and cultural appropriateness. Despite these potential benefits, this dietary pattern has not been tested in people with CKD. Therefore, we suggest key research questions targeting measurement of adherence, feasibility, and effectiveness of the Dieta de la Milpa in people with CKD.