Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, Netherlands.
Research Centre on Aging, Centre intégré universitaire de santé et de services sociaux de l'Estrie-Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie-CHUS), Sherbrooke, Quebec, Canada.
Am J Clin Nutr. 2021 Apr 6;113(4):972-983. doi: 10.1093/ajcn/nqaa360.
Dietary protein has been related to muscle function in aging. Beyond total intake, parameters such as protein distribution across meals might also be important.
We aimed to examine prospective associations of different protein intake parameters with muscle strength and physical performance in community-dwelling older men and women.
In total, 524 men and 574 women aged 67-84 y at baseline (T1) were followed annually for 3 y (T2, T3, T4). Outcomes included handgrip strength (kPa), knee extensor strength (kg), and physical performance (Timed Up and Go, s) at T4, and their 3-y changes (T4 minus T1). Protein intake parameters were assessed using nine 24-h recalls collected over 3 y (T1, T2, T3) and included daily total intake (g/d), number of protein-providing meals and snacks, and protein distribution across meals (expressed as CV). Associations were examined by multivariable linear regression models including all protein intake parameters simultaneously. Also, the optimal protein dose (g) per meal for the maximum effect size of total daily intake was determined.
Higher daily protein intake was associated with better knee extensor strength and physical performance at T4 in both sexes and less physical performance decline in women. Optimal protein doses per meal were 30-35 g in men and 35-50 g in women for these outcomes. In men, more uneven protein distribution was associated with better physical performance at T4 and less handgrip strength decline. In women, a higher number of protein-providing snacks was associated with better handgrip strength and knee extensor strength at T4 and less handgrip strength decline. In neither sex was number of protein-providing meals associated with outcomes.
Higher daily protein intake, up to 30-50 g protein/meal, may contribute to better knee extensor strength and physical performance in generally well-functioning older men and women. More aspects of protein intake may contribute to muscle strength and physical performance than solely the daily quantity, notably the protein dose per meal.
膳食蛋白质与衰老过程中的肌肉功能有关。除了总摄入量外，蛋白质在各餐中的分布等参数也可能很重要。
我们旨在研究不同蛋白质摄入参数与社区居住的老年男性和女性肌肉力量和身体表现的前瞻性关联。
共有 524 名男性和 574 名女性在基线（T1）时年龄为 67-84 岁，随访 3 年（T2、T3、T4）。结局包括 T4 时的手握力（kPa）、膝关节伸肌力量（kg）和身体表现（起立行走测试，s），以及 3 年的变化（T4 减去 T1）。蛋白质摄入参数通过在 3 年内收集的 9 次 24 小时回顾法（T1、T2、T3）评估，包括每日总摄入量（g/d）、提供蛋白质的餐数和小吃数以及各餐之间的蛋白质分布（以 CV 表示）。通过同时包含所有蛋白质摄入参数的多变量线性回归模型检查关联。还确定了每餐最大总日摄入量的最佳蛋白质剂量（g）。
在两性中，较高的每日蛋白质摄入量与 T4 时更好的膝关节伸肌力量和身体表现相关，而女性的身体表现下降幅度较小。对于这些结局，男性每餐的最佳蛋白质剂量为 30-35 g，女性为 35-50 g。在男性中，蛋白质分布越不均匀，T4 时的身体表现越好，手握力下降幅度越小。在女性中，提供蛋白质的小吃数量越多，T4 时的手握力和膝关节伸肌力量越好，手握力下降幅度越小。在两性中，提供蛋白质的餐数与结局均无关。
较高的每日蛋白质摄入量，高达 30-50 g 蛋白质/餐，可能有助于一般身体功能良好的老年男性和女性更好地维持膝关节伸肌力量和身体表现。与每日蛋白质总量相比，蛋白质摄入的更多方面可能对肌肉力量和身体表现有贡献，尤其是每餐的蛋白质剂量。
