Sarcopenia, also known as muscle loss, is a common condition that affects 10% of adults who are over 50 years old.
While it can decrease life expectancy and quality of life, there are actions you can take to prevent and even reverse the condition.
Although some of the causes of sarcopenia are a natural consequence of aging, others are preventable. In fact, a healthy diet and regular exercise can reverse sarcopenia, increasing lifespan and quality of life.
This article explains what causes sarcopenia, and lists many ways you can fight it.
What Is Sarcopenia?
Sarcopenia literally means “lack of flesh.” It’s a condition of age-associated muscle degeneration that becomes more common in people over the age of 50.
Sarcopenia is caused by an imbalance between signals for muscle cell growth and signals for teardown. Cell growth processes are called “anabolism,” and cell teardown processes are called “catabolism” (6).
For example, growth hormones act with protein-destroying enzymes to keep muscle steady through a cycle of growth, stress or injury, destruction and then healing.
This cycle is always occurring, and when things are in balance, muscle keeps its strength over time.
Although aging is the most common cause of sarcopenia, other factors can also trigger an imbalance between muscle anabolism and catabolism.
1. Immobility, Including a Sedentary Lifestyle
Disuse of muscle is one of the strongest triggers of sarcopenia, leading to faster muscle loss and increasing weakness (8).
Bed rest or immobilization after an injury or illness leads to rapid loss of muscle (9).
Although less dramatic, two to three weeks of decreased walking and other regular activity is also enough to decrease muscle mass and strength (9).
Periods of decreased activity can become a vicious cycle. Muscle strength decreases, resulting in greater fatigue and making it more difficult to return to normal activity.
2. Unbalanced Diet
A diet providing insufficient calories and protein results in weight loss and diminished muscle mass.
Unfortunately, low-calorie and low-protein diets become more common with aging, due to changes in sense of taste, problems with the teeth, gums and swallowing, or increased difficulty shopping and cooking.
To help prevent sarcopenia, scientists recommend consuming 25–30 grams of protein at each meal (10).
After injury or illness, inflammation sends signals to the body to tear down and then rebuild the damaged groups of cells.
Chronic or long-term diseases can also result in inflammation that disrupts the normal balance of teardown and healing, resulting in muscle loss.
For example, a study of patients with long-term inflammation resulting from chronic obstructive pulmonary disease (COPD) also showed that patients had decreased muscle mass (11).
Examples of other diseases that cause long-term inflammation include rheumatoid arthritis, inflammatory bowel diseases like Crohn’s disease or ulcerative colitis, lupus, vasculitis, severe burns and chronic infections like tuberculosis.
A study of 11,249 older adults found that blood levels of C-reactive protein, an indicator of inflammation, strongly predicted sarcopenia (12).
4. Severe Stress
Sarcopenia is also more common in a number of other health conditions that increase stress on the body.
In chronic kidney disease, stress on the body and decreased activity lead to muscle loss (15).
Cancer and cancer treatments also place great stress on the body, resulting in sarcopenia (16).
SUMMARY: In addition to aging, sarcopenia is accelerated by low physical activity, insufficient calorie and protein intake, inflammation and stress.
NEXT: How to Tell If You Have Sarcopenia