Prevention of Loss of Muscle Mass and Function in Older Adults during COVID-19 Lockdown: Potential Role of Dietary Essential Amino Acids

Abstract

As the COVID-19 pandemic became a global emergency, social distancing, quarantine, and limitations in outdoor activities have resulted in an environment of enforced physical inactivity (EPI). A prolonged period of EPI in older individuals accelerates the deterioration of skeletal muscle health, including loss of muscle mass and function, commonly referred to as sarcopenia. Sarcopenia is associated with an increased likelihood of the progression of diabetes, obesity, and/or depression. Well-known approaches to mitigate the symptoms of sarcopenia include participation in resistance exercise training and/or intake of balanced essential amino acids (EAAs) and high-quality (i.e., containing high EEAs) protein. As the pandemic situation discourages physical exercise, nutritional approaches, especially dietary EAA intake, could be a good alternative for counteracting against EPI-promoted loss of muscle mass and function. Therefore, in the present review, we cover (1) the impact of EPI-induced muscle loss and function on health, (2) the therapeutic potential of dietary EAAs for muscle health (e.g., muscle mass and function) in the EPI condition in comparison with protein sources, and finally (3) practical guidelines of dietary EAA intake for optimal anabolic response in EPI.

Impact of the COVID-19 pandemic on risk of sarcopenia: From lockdown and infection perspectives: A systematic review and meta-analysis

“…[39] Therefore, the adoption of preventive measures against sarcopenia, such as sufficient dietary protein consumption and resistance training, is crucial. [40] This review is the first meta-analysis of the impact of the COVID-19 pandemic on the risk of sarcopenia, including observational studies and randomized controlled trials conducted in different countries. However, it inevitably had some limitations.…”

Organokines in COVID-19: A Systematic Review

“…The MaFbx/MuRF1 is a wellestablished inducer of sarcopenia. The IGF-1-AKT-mTOR induces muscle hypertrophy when stimulated, but when inhibited during disease immobilization, it causes muscle degeneration [18,139,140].…”

“…When myostatin activation is elevated, such as during COVID-19 infection, the SMAD complexes become less unavailable to the BMPs, and the skeletal muscles lose proteins. Taken together, all events during new onset acute sarcopenia in COVID-19 infection induced muscular autophagy via increased mitochondrial dysfunction and decreased mitochondrial biogenesis, which decreases skeletal muscles synthesis and increases not only myofibrillar breakdown but also skeletal muscles degradation [18,[140][141][142].…”

Physical Activity and Diet in Older Women: A Narrative Review

“…A prolonged period of sedentary behaviour and inactivity in older individuals accelerates the deterioration of skeletal muscle health, including loss of muscle mass and function. Decreased muscle mass in older adults is associated with increased mortality and reduced quality of life [77].…”