Dietary protein intake is associated with better physical function and muscle strength among elderly women

Abstract

Dietary protein intake might be beneficial to physical function (PF) in the elderly. We examined the cross-sectional and prospective associations of protein intake of g/kg body weight (BW), fat mass (FM) and lean mass (LM) with PF in 554 women aged 65·3-71·6 years belonging to the Osteoporosis Risk Factor and Prevention Fracture Prevention Study. Participants filled a questionnaire on lifestyle factors and 3-d food record in 2002. Body composition was measured by dual-energy X-ray absorptiometry, and PF measures were performed at baseline and at 3-year follow-up. Sarcopaenia was defined using European Working Group on Sarcopenia in Older People criteria. At the baseline, women with higher protein intake (≥1·2 g/kg BW) had better performance in hand-grip strength/body mass (GS/BM) (P = 0·001), knee extension/BM (P = 0·003), one-leg stance (P = 0·047), chair rise (P = 0·043), squat (P = 0·019), squat to the ground (P = 0·001), faster walking speed for 10 m (P = 0·005) and higher short physical performance battery score (P = 0·004) compared with those with moderate and lower intakes (0·81-1·19 and ≤0·8 g/kg BW, respectively). In follow-up results, higher protein intake was associated with less decline in GS/BM, oneleg stance and tandem walk for 6 m over 3 years. Overall, results were no longer significant after controlling for FM. Associations were detected between protein intake and PF in non-sarcopaenic women but not in sarcopaenic women, except for change of GS (P = 0·037). Further, FM but not LM was negatively associated with PF measures (P < 0·050). This study suggests that higher protein intake and lower FM might be positively associated with PF in elderly women.

Even mealtime distribution of protein intake is associated with greater muscle strength, but not with 3-y physical function decline, in free-living older adults: the Quebec longitudinal study on Nutrition as a Determinant of Successful Aging (NuAge study)

“…Protein intake might improve function possibly through an effect on muscle quality (i.e., strength per kilogram of lean mass) (55) or muscle-fiber contractility (56). However, similar to the protein distribution, 3-y changes in physical performance were not affected by total dietary protein, which was consistent with other recent findings (57) but not all results (5).…”

Dietary protein is associated with musculoskeletal health independently of dietary pattern: the Framingham Third Generation Study ,

“…Greater dietary protein has been shown to reduce age-related loss of bone density (6)(7)(8), muscle mass (9)(10)(11), and muscle strength (12)(13)(14)(15). Although the benefits of attaining adequate protein in the diet to optimize musculoskeletal health have been well established, it remains unknown whether these benefits occur as a result of absolute protein intake (i.e., attaining a specific dietary allowance in grams per day) or whether maximizing protein intake from specific food sources is of importance.…”

Sarcopenia-A baby boomers dilemma for nurse practitioners to discover, diagnose, and treat

“…Greater muscle protein synthesis and muscle mass and strength have been linked with the ingestion of both a more even distribution of protein among daily meals and a sufficient total amount of protein each day. [79][80][81][82][83][84][85][86][87][88][89] Dietary protein intake among most Americans is typically higher at the evening meal versus at breakfast and lunch, and many older adults fail to consume adequate dietary protein. [82,[90][91][92][93] Nurse practitioners can educate and emphasize to their patients about the importance of eating protein-rich food sources at each meal.…”