Association between dietary protein intake and frailty index among home-dwelling older adults; an 8-year follow-up study

BACKGROUND: The World's population is getting older, and healthy behavior such as a healthy diet may prevent the development of frailty and promote healthy ageing. In this study, we aimed to investigate the association between dietary protein intake and longitudinal changes in frailty among older, home-dwelling subjects. METHOD: Data were obtained from 130 home-dwelling, Norwegian older adults (70+) at baseline and after 8-year follow-up. Frailty was measured by a frailty index (FI) based on an accumulation of 38 deficits, scored 0-1. Dietary protein intake was collected by 2 × 24-h recall per visit. The association between dietary intake at baseline and change in FI was analysed by linear regression modelling. Changes in diet and changes in FI between the two visits were analyzed by Spearman's rank correlation coefficient. RESULTS: The FI score significantly increased from baseline to follow-up (0.12 vs 0.2, p < 0.001), and more subjects were categorised as frail at the follow-up visit (3% vs 33%, p < 0.001). Overall, there was no significant association between dietary protein intake at baseline or change in dietary intake and change in FI score. We did, however, observe a decreased intake of protein (E %) and meat (g) after 8-year follow-up. CONCLUSIONS: Our findings suggest that frailty accelerates with age, independent of dietary protein intake. A healthy diet may delay the rate of frailty, however, even if the dietary intake of protein remains stable after 8-year follow-up, it could not prevent the frailty process in our study population. Thus, more studies are needed to describe what factors that might accelerate or prevent the accumulation of frailty deficits with advancing years.