Dietary Protein and Preservation of Physical Functioning Among Middle-Agedand Older Adults in the Framingham Offspring Study

摘要

Dietary protein may help prevent age-related declines in strength and functionalcapacity. This study examines the independent relationship between dietary protein andlongitudinal changes in physical functioning among adults participating in the FraminghamOffspring Study from examination 5 (1991–1995) to examination 8 (2005–2008). Proteinintakes were derived from 3-day diet records during examinations 3 and 5; functionalstatus was determined over 12 years using 7 items selected from standardizedquestionnaires. Multivariable models adjusted for age, sex, education, physical activity,smoking, height, and energy intake. Functional tasks that benefitted most from ahigher-protein diet (≥1.2 g/kg/day vs. <0.8 g/kg/day) were doing heavy work at home,walking 1/2 mile (0.8 km), going up and down stairs, stooping/kneeling/crouching, andlifting heavy items. Those with higher protein intakes were 41% less likely (95% CI: 0.43,0.82) to become dependent in 1 or more of the functional tasks over follow-up. Higherphysical activity and lower body mass index were both independently associated with lessfunctional decline. The greatest risk reductions were found among those with higherprotein intakes combined with either higher physical activity, more skeletal muscle mass,or lower body mass index. This study demonstrates that dietary protein intakes above thecurrent US Recommended Daily Allowance may slow functional decline in older adults.