Sarcopenia is the loss of muscle mass due to the natural aging process.
This decrease in muscle leads to a reduction in a person's strength. As a result, their balance and gait are also affected.
Sarcopenia can have an impact on a person's ability to perform everyday activities, such as climbing stairs, lifting objects, and walking.
According to the International Osteoporosis Foundation (IOF), muscle mass starts to decline around the age of 40. The loss of muscle tissue may progress more rapidly when a person reaches their 60s and 70s.
Although the exact rate of decline varies, a person may lose 3 to 8 percent of muscle mass per decade.
The loss of muscle mass involves both a reduction in the number of muscle fibers and a decrease in their size. The combination of fewer and smaller muscle fibers causes the muscles to atrophy or shrink.
As a person ages, certain changes take place in the body that play a role in the development of sarcopenia.
For example, as a person gets older, their body's ability to produce the proteins that the muscles need to grow decreases. When protein production falls, individual muscle cells get smaller.
Age-related hormonal changes may also lead to a decrease in muscle mass. Typically, levels of testosterone and insulin-like growth factor (IGF-1) affect muscle growth and muscle mass.
The decline in hormone levels may be a contributing factor to the loss of muscle mass.
Although aging is the main cause of sarcopenia, other factors contribute to the loss of muscle mass. They include:
- Living a sedentary lifestyle: Getting little or no physical activity on a regular basis puts people at an increased risk of developing sarcopenia as they age.
- Poor nutrition: Poor dietary habits can also contribute to the development of sarcopenia. Although poor nutrition is possible at any age, it may affect how fast muscle mass declines in older adults.
Older adults tend to eat less, which can lead to malnutrition. According to IOF, up to 41 percent of women and 38 percent of men over the age of 50 eat less protein than the recommended daily allowance.
Eating large amounts of acid producing foods, such as grains and processed foods, and eating too few vegetables and fruits may also negatively affect muscle mass.
Symptoms of sarcopenia may vary depending on how much muscle mass a person has lost. Symptoms include:
- a decrease in muscle size
- loss of endurance
- poor balance
- trouble climbing stairs
A decline in muscle mass may not seem like a big concern for most people. However, muscle loss can be significant enough to cause weakness, increase fall risk, and limit a person's independence.
Sarcopenia may also cause a person to reduce their participation in physical activities. This decrease in activity causes even further muscle loss, which can adversely affect a person's quality of life.
Doctors often diagnose sarcopenia based on the symptoms an individual reports.
In some cases, a doctor may recommend a dual energy X-ray absorptiometry (DXA) and a walking speed test to make a diagnosis.
DXA uses low-energy X-rays to measure skeletal mass. DXA usually measures bone density and tests for osteoporosis. When used in combination with walking speed tests, it may be helpful in diagnosing sarcopenia.
In some instances, doctors may perform additional tests, such as measuring handgrip strength.
Currently, there are no medications approved by the U.S. Food and Drug Administration (FDA) to treat sarcopenia.
Some research is investigating the use of hormone therapy to increase lean muscle mass.
Researchers are studying the use of testosterone and growth hormones to help people maintain muscle mass as they age. But further studies are needed before hormone therapy is recommended to treat sarcopenia.
Instead of medication or hormone therapy, management of sarcopenia focuses on lifestyle changes to prevent muscle loss. These usually include:
When it comes to muscle mass, the old saying "use it or lose it" is true. Working the muscles helps maintain muscle mass and strength. When muscles are not used, they shrink.
Strength training or resistance training can improve muscle size, strength, and tone. It can also strengthen bones, ligaments, and tendons, which is good for a person's overall health.
According to the Centers for Disease Control and Prevention (CDC), older adults should participate in muscle-strengthening activities a minimum of 2 days a week. They should exercise all the major muscle groups, which include the legs, arms, chest, shoulders, back, and abdomen.
Strength training involves using resistance to cause muscle contraction. The muscle contraction builds muscle size and increases strength.
Strength training may involve using weights, resistance bands, or exercise machines. A person's own body weight can also be used for resistance.
It can be beneficial to work with an exercise trainer to develop a strength training program that is effective and safe.
Older adults should consult a doctor before starting a new exercise program. A doctor can make sure there are no health problems present that would prevent someone doing resistance training.
Proper nutrition is essential to treat sarcopenia, and may even prevent or delay the condition.
Eating enough protein is an important dietary consideration in preventing sarcopenia. The IOF recommend that adults eat 1.0-1.2 grams of protein per kilogram of bodyweight daily.
The United States Department of Agriculture (USDA) recommends choosing skinless poultry and lean cuts of beef when looking for meat-based protein sources.
Seafood, such as trout and salmon, can also be good sources of protein, while tofu, lentils, beans, and quinoa are popular protein sources for people who do not eat meat.
When choosing which protein-rich foods to eat, reading food labels can be helpful. Select sources of protein that do not have excessive amounts of sodium, fat, and cholesterol.
Taking certain dietary supplements may be another way to improve sarcopenia or help prevention the condition.
For example, taking creatine supplements may increase strength and lean muscle mass in adults of any age.
Similarly, maintaining adequate levels of vitamin D, either through diet or supplements, may help older adults maintain muscle strength.
Before taking any supplements, a person should always talk to a doctor.
Although aging is inevitable, developing sarcopenia does not have to be. Fortunately, there are steps people can take that decrease their chances of losing significant muscle mass.
Even if muscle loss has occurred, proper diet and strength training can help people with sarcopenia have a positive outlook and make improvements to the condition.