Background: Consumption of high-quality protein foods or supplements are associated with acutely elevating muscle protein synthesis and suggested to assist with muscle preservation across the aging process. Maintaining muscle mass, in return, is hypothesized to be beneficial for improving markers of physical function, which is important not only in older adults but also middle-aged populations. On a per gram basis, lean beef is one of the densest proteins and a strong contributor of the amino acid leucine, an activator of muscle protein translation efficiency within skeletal muscle.
Aim: To review evidence for evaluating the associations between beef intake and functional performance in middle-aged and older adults. Methods A narrative search was conducted through October, 2019.
Results: Included articles was 20; nine randomized controlled trials, six cross-sectional investigations, three prospective cohort, and two randomized repeated measures studies. Almost all of the studies did not evaluate beef consumption directly, but instead evaluated beef consumption as part of animal-based protein consumption. No studies directly compared the associations of beef consumption to functional performance.
Conclusion: Based on the articles in this review, evidence of a direct relationship between beef intake and functional performance in middle-age and older adults is lacking. Dietary assessments did not distinguish beef from other foods, thereby making it challenging to determine a causal impact of beef on specific measures of functional performance. Therefore, we suggest that more studies directly measure beef consumption and determine how beef is associated with functional performance. Such information will provide insights for interventions aiming to preserve functioning through diet.