Sarcopenia
Progressive age-related loss of muscle mass and strength, starting from age 30 and accelerating after 60, with major consequences for independence and health.
Sarcopenia is the muscle wasting of ageing. From age 30, you lose about 3 to 8% of muscle mass per decade, accelerating after 60 (up to 1 to 2% a year). It reduces strength, balance and metabolism, and increases the risk of falls, fractures, loss of independence and mortality.
An original angle (anabolic resistance): with age, muscles become “deaf” to protein. This is “anabolic resistance”. The same protein-rich meal stimulates less muscle synthesis in an older person than in a young one.
Counter-intuitive practical consequences:
- Older adults need MORE protein than younger people (1.0 to 1.2 g/kg/day versus 0.8), contrary to the belief that “we eat less as we age”
- A leucine threshold per meal (about 2.5 to 3 g, or about 25 to 30 g of protein) is needed to “wake up” synthesis: it is better to spread protein over the 3 meals than to concentrate it all in the evening
- Protein alone is not enough: resistance exercise (weight training) is the essential trigger
Sarcopenia is not inevitable: it is largely a consequence of sedentary habits plus insufficient protein intake. 80-year-olds who train gain muscle. Muscle is a “metabolically precious” organ: it regulates blood glucose, produces anti-inflammatory myokines and protects bones.
Vitamin D and omega-3s also seem to support muscle function in older adults.