The relationship between nutrition and frailty: Effects of protein intake, nutritional supplementation, vitamin D and exercise on muscle metabolism in the elderly. A systematic review

Background: Frailty is a geriatric syndrome that predicts the onset of disability, morbidity and mortality in elderly people; it is a state of pre-disability and is reversible. The aim of this review is to assess how nutrition influences both the risk of developing frailty and its treatment. Data sources: We searched two databases, PubMed and Web of Science. We included epidemiologic studies and clinical trials carried out on people aged over 65 years. We included 32 studies with a total of over 50,000 participants. Results: The prevalence of frailty is ranges from 15% among elderly people living in the community to 54% among those hospitalized. Furthermore, the prevalence of frailty is disproportionately high among elderly people who are malnourished. Malnutrition, which is very prevalent in geriatric populations, is one of the main risk factors for the onset of frailty. A good nutritional status and, wherever necessary, supplementation with macronutrients and micronutrients reduce the risk of developing frailty. Physical exercise has been shown to improve functional status, helps to prevent frailty and is an effective treatment to reverse it. Despite the relatively large number of studies included, this review has some limitations. Firstly, variability in the design of the studies and their different aims reduce their comparability. Secondly, several of the studies did not adequately define frailty. Conclusions: Poor nutritional status is associated with the onset of frailty. Screening and early diagnosis of malnutrition and frailty in elderly people will help to prevent the onset of disability. Effective treatment is based on correction of the macro- and micronutrient deficit and physical exercise. (C) 2016 Elsevier Ireland Ltd. All rights reserved.