Leucine-enriched Protein Supplementation for the Pre-frail: What Are the Benefits?
It is known that one in five adults with pre-frailty progresses to frailty over a 3-year period. Low protein and energy intake, increased prevalence of multimorbidity, and a sedentary lifestyle are well-characterised drivers of sarcopenia. Consequently, they act as catalysts of older adults’ transition to frailty. In this vein, stimulating increased muscle protein synthesis through regular physical exercise and protein-enriched diet consumption is pivotal for pre-frail older adults. Current U.S. Food and Nutrition Board guidelines recommend a dietary allowance of 0.8 g/kg of protein per day for older adults. However, this amount may be insufficient for those with pre-frailty due to their low-grade inflammation, multimorbidity, and increased susceptibility to anabolic resistance.
This study aimed to examine the impact of leucine-enriched protein supplementation with or without exercise on 1) physical function, 2) body composition, and 3) systemic inflammation in pre-frail older adults with a daily protein consumption of ≤1 g/kg.
Key learnings:
At the three-month mark, significant improvements in physical function (gait speed, 5× STS, GDS and total SPPB scores, perceived health), as well as body composition (FFMI, ASMI, and body cell mass) and systemic inflammation (IL-6 and TNF-α levels), were noted in participants undergoing both nutritional and exercise interventions. Conversely, patients who exclusively received leucine-enriched protein supplementation only noted significant improvements in body cell mass and inflammatory biomarkers. Importantly, these changes were not sustained after discontinuing the interventions, indicating their significant contribution to the reported outcomes. Future research must aim to validate these findings in larger longitudinal randomised trials recruiting pre-frail older adults with insufficient protein intake.
Reviewed by: S. Duarte
Authors: Merchant RA, Chan YH, Anbarasan D et al.
Published in: Frontiers in Medicine (August 2023)
