Provision of High Protein Foods Slows the Age-Related Decline in Nutritional Status in Aged Care Residents: A Cluster-Randomised Controlled Trial

Abstract

Objectives: Malnutrition, particularly protein insufficiency, is common in institutionalised older adults and increases morbidity, mortality, and costs. We aimed to determine whether 12 months supplementation using high-protein foods (milk, cheese, yoghurt) prevents malnutrition in older adults. Design: Cluster randomised control study. Setting: Sixty Australian aged care facilities. Participants: Older adults living in aged care homes (n=654, mean age 86.7±7.2 years, 72% females). Intervention: Facilities randomly allocated to a high-protein (n=30 intervention) or regular (n=30 controls) menu. Measurements: Nutritional status assessed using the Mini Nutrition Assessment (MNA) tool and fasting morning blood samples (n=302) assayed for haemoglobin (Hb) and albumin. Food intake was monitored 3-monthly using visual plate waste assessment. Measurements at baseline and month 12 were analysed using random effects model accounting for clustering (facility), repeated measure and confounders. Results: Addition of 11g of protein as 1.5 servings of high-protein foods daily preserved nutritional status that deteriorated in controls [MNA screen (−0.68, 95%CI: −1.03, −0.32, p<0.001) and total (−0.90, 95%CI: −1.45, −0.35, p=0.001) scores], resulting in group differences in MNA screen (0.62, 95%CI: 0.17, 1.06, p=0.007) and total (0.81, 95%CI: 0.11, 1.51, p=0.023) scores and group difference in Hb (3.60g/L, 95%CI: 0.18, 7.03, p=0.039), the net result of preservation with intervention (0.19g/L, 95%CI: −2.04, 2.42, p=0.896) and a decline in controls (−3.41g/L, 95%CI: −6.01, −0.82, p=0.010). No group differences were observed for serum albumin. Conclusion: Consumption of high-protein foods is a pragmatic approach to maintaining nutritional status in older adults in aged-care.