Date of Award

2025

Document Type

Thesis - ECU Access Only

Publisher

Edith Cowan University

Degree Name

Master of Medical and Health Science by Research

School

School of Medical and Health Sciences and Nutrition / Health Innovation Research Institute

First Supervisor

Marc Sim

Second Supervisor

Jack Dalla Via

Third Supervisor

Simone Radavelli-Bagatini

Fourth Supervisor

Cassandra Smith

Abstract

Frailty is a complex medical condition that is attracting attention globally due to the rapidly increasing ageing population. In older adults, frailty is a key contributor to functional decline with impacts on quality of life and premature mortality, which is becoming increasingly prevalent. Frailty is largely preventable, leading to a large body of research exploring strategies and interventions that may stop its onset or progression. Exercise, nutrition, behavioural and cognitive therapy, and individually adapted care are some of the common strategies to combat frailty. Notably, nutritional status is identified as a key factor in frailty assessment that has gained considerable attention. Understanding nutritional factors that contribute to its development is crucial for optimising health interventions and improving quality of life. Previous work by our research team identified that both dietary protein and dietary nitrate may play a significant role on frailty status. As such, both factors were explored independently, with the focus of my thesis on protein intake, including its source.

The literature review (Chapter 1) provides an extensive overview of existing knowledge on frailty and nutrition, whilst identifying gaps within the literature that directed the current project. As frailty is increasingly recognised as a multidimensional condition, encompassing physical, social, and cognitive aspects, the frailty index (FI) offers a more comprehensive evaluation compared to other tools such as the physical frailty phenotype. Despite this, limited studies have explored the association between protein intake and a multidimensional measure of frailty. Furthermore, the importance of plant and animal-based protein intakes to this relationship remains unclear. As part of my research project, I developed and validated a FI for community-dwelling older women, a population with the highest risk for frailty. This involved selecting 33 key variables that would best represent the multidimensional nature of frailty, including variables across numerous health domains.

My primary research project (Chapter 2) was a cross-sectional analysis of the relationship between protein intake (total, plant, and animal) and frailty, assessed using the FI, in older Australian community-dwelling women. To our knowledge, this is the first Australian study adopting the FI to explore the association between protein intake and frailty. My work identified that odds for frailty decreased progressively with higher total protein intake, with 49% lower odds when intake was ~1.6 g/kg of bodyweight per day (BW/d) (median Q4), compared to women with the lowest protein intake Q1 (median 0.77 g/kg BW/day). Plant protein intake was also associated with reduced lower frailty odds by 65% when intakes were ~0.6 g/kg BW/d (median Q4), while animal protein was associated with 28% lower odds with intakes of ~0.8 g/kg BW/d (median Q3), compared to women with the lowest intakes Q1 (median 0.27 g/kg BW/day) and (median 0.44 g/kg BW/day), respectively. These findings highlight the potential value of both animal and plant protein in preventing and managing frailty, suggesting a balanced dietary approach comprising both plant and animal protein may be most beneficial when considering frailty.

DOI

10.25958/3wzv-ry47

Download

Share

 
COinS