What is sarcopenia and how do you prevent the loss of muscle mass at older age?

Sarcopenia is the age-related loss of both muscle mass and muscle strength or physical performance. Low muscle mass alone is not sufficient for a diagnosis: muscle function must also be impaired. Reviews estimate the prevalence at 5 to 10 percent in the general population, but depending on the measurement method used, this can rise to as much as 24 percent. In addition to ageing itself, physical inactivity, chronic disease and insufficient protein intake all play a role.

Sarcopenia has tangible consequences. Low handgrip strength and slow walking speed each independently predict falls, hip fractures, mobility problems and premature death in community-dwelling older adults. A notable detail: in several large studies of community-dwelling older adults, the amount of muscle mass measured on a scan turned out NOT to be independently associated with those outcomes. What matters, therefore, is more what your muscles can do than how much tissue is measurable. In people who simultaneously have low muscle mass and high fat mass (sarcopenic obesity), the risks are even greater.

Resistance training is the best-supported approach to preventing or treating sarcopenia. It is not feasible for everyone, however, particularly for people with physical limitations. Nutrition is the second pillar: a protein intake of at least 1.2 to 1.6 grams per kilogram of body weight per day appears to work better than the commonly recommended 0.8 grams. The amount per meal and the timing of intake also play a role. Concerns about kidney or bone damage from higher protein intake are not supported by the available research in healthy adults.

A combination of adequate protein, physical exercise and addressing underlying inflammation produces the best results. Medications specifically targeting muscle building, such as agents that block an inhibitor of muscle growth, are still being investigated and have not yet been proven effective for routine use.

Sarcopenia is established by measuring muscle mass and testing muscle function, for example through a walking speed test or handgrip strength measurement. A walking speed below 1 metre per second combined with low muscle mass is a commonly used diagnostic threshold. No usable blood markers are currently available.