What is Sarcopenia? Causes and Prevention of Age-Related Muscle Loss

Introduction

Sarcopenia is a condition characterized by the loss of muscle mass and strength that occurs with aging. While some amount of muscle loss is normal as we get older, sarcopenia can dramatically impact mobility, independence, and quality of life.


In this post, we’ll dive into what exactly sarcopenia is, who’s at risk, and most importantly—how to prevent and fight this common age-related decline in muscle and function. Keep reading to learn why sarcopenia matters, and how simple lifestyle strategies can help you or a loved one stay strong, active, and independent for life.

What is Sarcopenia?

Sarcopenia comes from the Greek words “sarx” meaning flesh and “penia” meaning loss. It’s officially defined as the degenerative loss of skeletal muscle mass, quality, and strength associated with aging.


While we start to lose muscle mass relatively early in adulthood, most noticeable muscle wasting typically begins around age 40. Without intervention, sarcopenia progresses to impact muscle strength and physical function.


There are generally three stages:

  • Presarcopenia: Characterized by low muscle mass without impact on strength or function
  • Sarcopenia: Reduced muscle mass plus low muscle strength or function
  • Severe sarcopenia: Dramatic loss of muscle mass and strength with functional impairment

Estimates suggest that over 50 million people worldwide have sarcopenia (1), with prevalence increasing to over 50% of people in their 80s (2). But keep in mind—sarcopenia can start much as early as in our 30s and 40s. So sarcopenia shouldn't be thought of as only an "old person" condition - it can start progressively at relatively young ages.

What Causes Sarcopenia?

A variety of factors contribute to the development and progression of sarcopenia as we age. The main reasons include:

  • Aging itself: As we get older, muscle fibers shrink, decrease in number, and become less efficient at rebuilding muscle tissue after injury or breakdown. The ability of muscle stem cells to regenerate muscle declines.
  • Decreased activity: Lack of exercise and muscle disuse leads to atrophy and wasting of muscle tissue. Sedentary seniors who aren't active have an accelerated progression of sarcopenia.
  • Hormonal changes: Declining levels of growth hormone, IGF-1, testosterone, and estrogen with aging affect the body's ability to maintain muscle mass.
  • Inadequate nutrition: Consuming too few calories, insufficient protein, and malnutrition hamper the body's capacity to synthesize new muscle proteins and maintain lean mass.

Some other factors that can spur the development of sarcopenia include conditions (like cancer, kidney disease, and diabetes) as well as some medications (like corticosteroids and chemotherapy).


So, sarcopenia has no single cause - its origins and development involve multiple interrelated factors with many contributing elements, rather than one distinct cause. This multifactorial nature of sarcopenia means a combination of lifestyle strategies is needed to prevent and treat it. Physical activity and proper nutrition are key, which we’ll discuss further.

Consequences of Sarcopenia

The loss of muscle mass, strength, and function characteristic of sarcopenia has many detrimental effects:

  • Physical impairment: Sarcopenia leads to reduced muscle strength affecting balance, gait, and mobility. Activities like walking, climbing stairs, getting up from chairs, and carrying objects become very difficult. Risk of falls and fractures rises.
  • Loss of independence: Impaired mobility and physical function lead to needing assistance with activities of daily living like bathing, dressing, household chores, and running errands. Independence declines.
  • Metabolic consequences: Loss of muscle mass decreases resting metabolic rate. This can increase body fat levels and the risk of obesity and associated chronic diseases like type 2 diabetes.
  • Cardiovascular effects: Sarcopenia is linked with higher inflammation levels that negatively impact the cardiovascular system and heart health.
  • Psychological effects: Social isolation, depression, anxiety, and reduced overall quality of life frequently accompany sarcopenia due to loss of strength, function and independence.
  • Mortality risk: Sarcopenia is associated with significantly higher mortality rates, especially in older populations. Life expectancy is reduced.

In short, untreated sarcopenia threatens independence, mobility, and vitality in later life. Screening to catch it early and taking preventative steps is crucial.

Who’s at Risk for Sarcopenia?

Sarcopenia risk generally increases with age, but other factors also raise susceptibility:

  • Older adults: Prevalence increases over age 50, with faster progression at age 75+.
  • Inactive people: Those with sedentary lifestyles are more prone to muscle wasting.
  • Malnourished: Poor nutrition, especially low protein, makes sarcopenia worse.
  • Chronic diseases: Diabetes, COPD, obesity, and heart disease all increase risk.
  • Smokers: Toxic compounds and inflammation promote muscle loss.

Genetics and ethnicity may also play a role. Talk to your doctor about evaluation if you’re concerned.

Can Sarcopenia be Prevented or Reversed?

The good news is that a great deal can be done to prevent, slow, and even reverse sarcopenia through lifestyle strategies.


Nutrition: Consuming enough calories and adequate high-quality protein is imperative for muscle maintenance. The amino acids in protein quite literally provide the building blocks muscles need for growth and repair. While younger adults are generally recommended to consume 0.8 grams of protein per kilogram of bodyweight on a daily basis to preserve muscle mass, older adults should aim for at least 1.2-1.5 grams of protein per kilogram of body weight daily to preserve muscle mass (3).


Get More Protein: Say it louder. More protein is key. Intentionally increasing protein from high quality sources like eggs, dairy, fish, poultry, and lean meat ensures maximal amino acid availability. Protein supplements can help meet needs. Lecithin, creatine, and vitamin D also support muscle growth.


Exercise: Physical activity is crucial to stimulate muscle growth and prevent wasting from disuse atrophy. Resistance training and weight lifting build muscle. If you’re currently not doing any resistance training, it is critical to start doing something. Anything will help. Even simple bodyweight exercises counteract loss from inactivity. Keep in mind that while resistance and balance training are very beneficial, exercises must be appropriate for age and functional status to prevent injury.


Anabolic stimuli: Other factors like adequate sleep, stress management, and hormone therapies help create an optimal environment for muscle anabolism. Dietary supplements can also support muscle maintenance. Examples include leucine, creatine, vitamin D, and Omega-3s.

Sarcopenia-Fighting Nutrition Tips

When it comes to nutrition, a diet high in protein should take center stage in any anti-sarcopenia eating plan. Here are some tips:

  • Consume protein at every meal: Spread protein intake out instead of just eating a large amount at dinner. Shoot for at least 25-30 grams per meal.
  • Focus on protein quality: Emphasize nutrient-dense sources like eggs, fish, poultry, lean red meat, dairy, legumes, nuts and seeds.
  • Include plant proteins: Variety ensures you get all essential amino acids. Soy foods like tofu are complete proteins.
  • Don’t restrict calories: Cutting calories leads to muscle breakdown. Get needed fuel to keep muscles fed.
  • Stay hydrated: Water supports muscle health and function. Aim for at least eight 8-oz glasses daily.
  • Opt for whole foods: Real foods provide protein along with beneficial nutrients foods provide. Avoid processed items with isolated protein sources or lots of additives.

Conclusion

As we've covered, sarcopenia is the age-related loss of muscle mass and strength that can dramatically impact mobility, independence, and quality of life in older adulthood. Although some muscle wasting is normal with aging, sarcopenia can accelerate this process and lead to impaired physical function if left unchecked.


The good news is that sarcopenia is not inevitable. By maintaining an active lifestyle with regular exercise and consuming a diet adequate in high-quality protein and calories, much can be done to fend off muscle loss and stay strong well into older age.

Implementing targeted mobility exercises, taking up resistance training, and optimizing nutrition to support muscle protein synthesis are proactive steps anyone can take. While more research is still needed, the lifestyle factors that combat sarcopenia are well established.


Don't wait - talk to your healthcare provider about screening for sarcopenia. Make muscle health and optimal nutrition a priority in your 60s, 70s and beyond. Stay socially engaged, keep moving your body every day, and eat a protein-rich diet to maintain strength, independence and vitality. Thriving in older age is absolutely achievable with simple proactive strategies starting today.

(1) Cruz-Jentoft, Alfonso J., et al. "Sarcopenia: revised European consensus on definition and diagnosis." Age and ageing 48.1 (2019): 16-31.

(2) Dhillon, R. J. S., & Hasni, S. (2017). Pathogenesis and Management of Sarcopenia. Clinics in geriatric medicine, 33(1), 17–26.

(3) Bauer, Jürgen M., et al. "Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE study group." Journal of the American Medical Directors Association 14.8 (2013): 542-559.