A loss of muscle mass, called sarcopenia, is a physiological age-related process and involves a progressive reduction of muscle strength. The physiological lean mass loss is believed to be in the order of about 3-8% per decade after the age of 30. Sarcopenic muscle loss is differentiated as either physiological or pathological. In the latter case, lean mass loss can also affect our ability to carry out daily activities.
Some of the main factors causing sarcopenia include physical inactivity, immobilisation, prolonged bed rest, the consequences of trauma, acute and chronic diseases, a reduced dietary intake of proteins, malnutrition, senescence, andropause and menopause. In particular, forced bed rest due to trauma or illness entails a rapid loss of mass and muscle strength, especially in the elderly, with the risk of a loss of personal autonomy.
The consequences of muscle mass loss
The loss of muscle mass with relative increase in fat mass causes a reduction in muscle strength, increased risk of falls due to the compromised stabilising effect of the muscles, reduced autonomy, and a predisposition to infectious processes. A ‘vicious cycle’ is thus created, which progressively aggravates the sarcopenia, worsening the decline of the person’s overall condition. The consequences of lean mass loss can affect numerous functions performed by proteins in the body (structural, enzymatic, transport, movement, respiratory, cardiac, immune, hormonal, gene).
Essential amino acids
Essential amino acids constitute the necessary building blocks for protein synthesis. In the elderly, taking a supplement with essential amino acids during forced bed rest, even for short periods, helps to preserve lean mass as well as muscle, cardiac and respiratory functionality. Studies have also shown that taking essential amino acids accelerates the reparative process in trophic ulcers. Another effect induced by essential amino acids is the facilitation and acceleration of functional recovery in subjects who have undergone surgery, especially in the orthopaedic field. Supplementation with essential amino acids is also helpful in physiological conditions in adults seeking to tone their body, by promoting an increase in lean mass with respect to fat mass, and also to maintain a healthy weight.