Nutrition and Frailty: A Review of Clinical Intervention Studies.

Frailty is one of the major health concerns in aging. It is considered a geriatric syndrome characterized by muscle weakness, sarcopenia and fatigue. It is also associated with several adverse health outcomes, including disability. Literature shows that there are a number of studies conducted to define the relationship between frailty and nutrition. The majority is from cross sectional, longitudinal, and cohort studies. Few intervention studies using micronutrients, macronutrients, nutritional supplement, or food regimens have been found. This review examines the nutrition intervention studies targeted towards older adults with frailty, and evaluates the effectiveness of nutrition interventions on frailty indicators. Twenty-four intervention studies from six electronic databases met the inclusion criteria. Sixteen were randomized controlled clinical trials; one was a quasi-experimental design, whilst the rest were controlled trials. Participants included in the studies differed in terms of age and frailty status. The studies were inconsistent in intervention type, duration, and targeted outcomes. Most of the studies indicated that modification of nutrition quality, either by giving supplements or by improving diet intake, could improve strength, walking speed, and nutritional status in majority of frail or pre-frail older adults. However, there was limited evidence on the effectiveness of intervention on inflammatory status and other biomarkers related to frailty due to limited number of studies targeting frailty biomarkers as a major outcome.