Association between protein intake from animal and plant sources and the presence of frailty in community-dwelling Australian women

We investigated the cross-sectional association between total, animal and plant protein intake with the presence of a multidimensional measure of frailty in older women. Participants included 1380 community-dwelling Australian women, mean (SD) age 75.1 (2.7) years. A validated food frequency questionnaire was used to determine total, plant, and animal protein intake. Frailty was assessed using a frailty index across numerous health domains (scored 0–1, ≥0.25 indicating frailty). Cross-sectional associations were analysed using multivariable-adjusted logistic regression models. In total, 275 (19.9%) women were identified as frail. A non-linear inverse association was observed between higher intakes of total protein and the odds for frailty. Compared to lowest protein intakes (Quartile [Q]1, 0.77 g/kg BW/d), greater intakes (up to 1.66 g/kg BW/d, Q4; OR 0.51 95%CI 0.31–0.82) were associated with lower odds for frailty. Higher plant (∼0.60 g/kg BW/d [Q4 vs Q1: OR 0.35 95%CI 0.22–0.57]) and animal (up to ∼0.80 g/kg BW/d; [Q3 vs Q1: OR 0.72 95%CI 0.53–0.97] protein intakes, were associated with lower odds for frailty. Older women consuming higher total protein, including a combination of animal and plant sources, were less likely to be frail, with intakes of ∼1.1–1.6 g/kg likely to be most beneficial.