Adequate dietary protein is associated with better physical performance among post-menopausal women 60–90 years

Abstract

Objectives Sarcopenia, the involuntary loss of skeletal muscle with age, affects up to one-quarter of older adults. Evidence indicates a positive association between dietary protein intake and lean muscle mass and strength among older persons, but information on dietary protein’s effect on physical performance in older adults has received less attention. Design Cross-sectional observational analysis of the relationship of dietary protein on body composition and physical performance. Setting Clinical research center. Participants 387 healthy women aged 60 – 90 years (mean 72.7 ± 7.0 y). Measurements Measures included body composition (fat-free mass, appendicular skeletal mass and fat mass) via dual x-ray absorptiometry (DXA), physical performance (Physical Performance Test [PPT] and Short Physical Performance Battery [SPPB]), handgrip strength, Physical Activity Scale in the Elderly (PASE), quality of life measure (SF-8), falls, fractures, nutrient and macromolecule intake (four-day food record). Independent samples t-tests determined mean differences between the above or below RDA protein groups. Statistical Analysis Analysis of covariance was used to control for body mass index (BMI) between groups when assessing physical performance, physical activity and health-related quality of life. Results The subjects consumed an average of 72.2 g protein/day representing 1.1 g protein/kg body weight/day. Subjects were categorized as below the recommended daily allowance (RDA) for protein (defined as less than 0.8 g protein/kg) or at or above the RDA (equal to or higher than 0.8 g protein/kg). Ninety-seven subjects (25%) were in the low protein group, and 290 (75%) were in the higher protein group. Women in the higher protein group had lower body mass, including fat and lean mass, and fat-to-lean ratio than those in the lower-protein group (p <0.001). Composite scores of upper and lower extremity strength were impaired in the group with low protein intake; SPPB score was 9.9±1.9 compared to 10.6±1.6 in those with higher protein intake and PPT was 19.8± 2.9 compared to 20.9± 2.1 in the low and higher protein groups, respectively. The results were attenuated by correction for BMI, but remained significant. The physical component of the SF-8 was also lower in the low protein group but did not remain significant when controlling for BMI. No significant differences were found in hand grip strength or reported physical activity. Conclusion Healthy, older postmenopausal women consumed, on average, 1.1 g/kg/d protein, although 25% consumed less than the RDA. Those in the low protein group had higher body fat and fat-to-lean ratio than those who consumed the higher protein diet. Upper and lower extremity function was impaired in those who consumed a low protein diet compared to those with a higher protein intake. Protein intake should be considered when evaluating the multi-factorial loss of physical function in older women.

Higher Protein but Not Energy Intake Is Associated With a Lower Prevalence of Frailty Among Community-Dwelling Older Adults in the French Three-City Cohort

“…38 Nevertheless, more research is needed in order to confirm this hypothesis because it is well established that an adequate caloric intake is needed to optimally utilize dietary protein to maintain muscle function rather than as E source. 39 Notwithstanding the importance of our results, this study has several limits. First, its cross-sectional design makes it difficult to assess the temporal relationship between protein intake and frailty.…”

Diet-induced acidosis and alkali supplementation

“…On the other side, protein consumption seems to be crucial for bone matrix development and overall bone health, especially in young and elderly subjects (Bonjour 2005;Gaffney-Stomberg et al 2009). Moreover, increase in dietary protein intake has also been correlated to a rise in IGF-I, muscle protein synthesis and physical performance, which are linked to bone status gain and decreased fracture risk (Alexy et al 2005;Heaney & Layman 2008;Gregorio et al 2014).…”

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)

“…Dietary proteins have been proposed as potentially important modifiable factors for maintaining physical performance in older adults (3)(4)(5). However, the effect of protein intake or supplementation on physical performance in elderly individuals at a population level remains to be clarified because inconsistent results have been reported in both cross-sectional (3,6) and longitudinal (4,5,7) studies.…”