Animal protein intake reduces risk of functional impairment and strength loss in older adults

Summary Background & aims Protein intake has been shown to lower risk of aging-related functional decline. The goal of this study was to assess long-term effects of weight-adjusted animal (AP) and plant protein (PP) intakes on aging-related change in functional status and grip strength. Methods Framingham Offspring Study participants (n = 1896, 891 men and 1005 women), ≥age 50, were followed for an average of 14.4 years. Protein intake derived from two sets of 3-day diet records (exams 3 and 5) was expressed as both weight-adjusted intake (from residuals) and per kilogram of body weight (g/kg/d). Seven tasks from two standardized assessments (Nagi and the Rosow–Breslau scales) were selected to determine functional status at exams 5–9. Functional impairment was defined as failure to complete (or having a lot of difficulty completing) a given task. Grip strength was assessed by dynamometer at exams 7–9. Results Participants with higher (vs. lower) weight-adjusted intakes of AP and PP maintained higher functional scores (p = 0.001 and p  Conclusions Higher AP intake and higher levels of physical activity and SMM were independently associated with lower risks of functional impairment and greater preservation of grip strength in adults over the age of 50 years.