Skeletal muscles power the human body and are essential to maintaining stability, function, and independence as we age. Most muscle mass is built throughout adolescence and maintained throughout adulthood. As adults age, muscle loss, known as sarcopenia, may occur. Sarcopenia is associated with deterioration in mobility, metabolism, and general well-being. Because the US population aged 65 and older is estimated to double in the next two decades, sarcopenia is an important health issue that needs to be addressed and prevented. (12)
What is Sarcopenia?
Sarcopenia is a musculoskeletal condition defined by losing muscle mass, strength, and function in older adults. Muscle loss and weakness can lead to falls, bone fractures, other serious injuries, and impaired ability to live independently. (1)
Primary sarcopenia is muscle loss that is associated with normal aging. Older age, lack of physical exercise, and poor nutrition increase the risk of primary sarcopenia. Secondary sarcopenia is the loss of muscle secondary to an underlying disease, including cancer, HIV, COPD, heart failure, and chronic kidney disease. (2)
Sarcopenia Signs & Symptoms
Symptoms of sarcopenia can vary, depending on the degree of muscle loss that has occurred. The most common symptom of sarcopenia is muscle weakness, but others may include:
- A decrease in muscle size
- Loss of physical endurance and stamina, making activities of daily living difficult to accomplish
- Trouble climbing stairs
- Poor balance and falls
Reduced activity levels inherently caused by sarcopenia lead to further muscle atrophy.
What Causes Sarcopenia?
In part, normal aging-related changes reduce muscle mass and function. These changes include reduced muscle fiber count, decreased tendon elasticity, slowed metabolic rate, and reduced hormone levels (IGF-1, testosterone, estrogen). However, the cause of sarcopenia is understood to be multifaceted, and many risk factors can expedite the progression, including malnutrition, a sedentary lifestyle, inflammatory pathway activation, and genetics. (3, 4)
Sarcopenia is associated with, and likely in part caused by, chronic diseases that negatively impact the musculoskeletal system, induce systemic inflammation, and impair the ability to partake in physical activity. These include COPD, chronic heart failure, chronic kidney disease, insulin resistance and diabetes mellitus, HIV, cancer, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). (1, 3)
Functional Medicine Labs to Test for Root Cause of Sarcopenia
The SARC-F Questionnaire is a screening tool that can be easily implemented in the primary care setting to identify probable sarcopenic patients. The questionnaire screens for self-reported signs suggestive of sarcopenia, including deficiencies in strength, walking, rising from a chair, climbing stairs, and experiencing falls.
Functional medicine labs help practitioners personalize treatment options for their patients. Below are some of the most common labs ordered for patients suffering from sarcopenia.
General Wellness Screening
Labs routinely ordered during an annual wellness screen, including a CBC, CMP, thyroid panel, and hemoglobin A1c (HbA1c), can be used to assess overall health and screen for numerous underlying health conditions associated with sarcopenia.
Insulin-like growth factor 1 (IGF-1) is a hormone that manages the effects of growth hormone (GH) in the body. Together, these two hormones promote the normal growth of bones and tissues. Adults with suboptimal IGF-1, and consequentially reduced GH, can have symptoms of fatigue, decreased bone density, and reduced muscle mass. (5)
Insulin is a pancreatic hormone that regulates blood sugar. Autoimmune destruction of pancreatic beta cells results in insulin-dependent type 1 diabetes. Insulin resistance is associated with reduced insulin sensitivity, which requires increased insulin production to regulate blood sugar; insulin resistance often progresses to type 2 diabetes when not addressed.
Sex hormones estrogen, progesterone, and testosterone can be measured in the blood, saliva, or urine to screen for low levels associated with menopause and andropause.
Inflammatory markers measured in the blood can measure systemic inflammation. These markers, including CRP and ESR, should be interpreted alongside other diagnostic labs and testing to determine the underlying cause of pathologic inflammation.
Comprehensive Nutritional Assessment
A comprehensive nutritional analysis, like Genova's NutrEval, measures essential vitamins, minerals, antioxidants, fatty acids, and amino acids required for overall health and muscle maintenance. Multiple deficiencies detected on a test like this indicate malnutrition.
It can be helpful to run a nutrient assessment alongside a stool analysis, which measures digestive enzymes, digestive products of nutrient breakdown, and inflammatory markers to screen for gastrointestinal factors contributing to maldigestion and malabsorption.
Conventional Treatment for Sarcopenia
Most interventions focus on increasing physical activity and optimizing nutrition. Clinical intervention studies demonstrate significant functional improvement through dietary interventions and resistance training. Resistance exercise training, in particular, profoundly increases muscle strength, size, and functional capacity in older adults. (3)
Functional Medicine Treatment Protocol for Sarcopenia
A functional medicine treatment protocol for sarcopenia emphasizes the importance of a healthy diet, aerobic exercise and resistance training, and managing chronic underlying conditions. A holistic, integrative approach reduces systemic inflammation, supports muscle strengthening, and optimizes general health and well-being.
Therapeutic Diet and Nutrition Considerations for Sarcopenia
There is a significant decline in food intake with increasing age, which is associated with chronic disease and sarcopenia. Nutrient-dense, whole organic foods provide the necessary macro and micronutrients, fiber, and antioxidants that can reduce the risk of chronic disease, lower inflammation, and promote longevity. Nutrient-dense foods include vegetables, fruits, legumes, whole grains, eggs, nuts, seeds, and lean meats/poultry. (6, 7)
Dietary protein sources provide the amino acids required to build and maintain muscle mass. Guidelines recommend eating 0.8-1.5 g of protein per kg body weight daily to maintain muscle function. High-protein foods include meats, poultry, seafood, soy, legumes, nuts, and eggs. (6, 7)
Increasing the intake of omega-3 fatty acids to optimize the omega-6:omega-3 ratio to 2-3:1 is associated with reduced systemic inflammation and decreased risk for heart disease, cancer, diabetes, arthritis, and autoimmune disease. Cold-water fatty fish, flaxseeds, and chia seeds are foods with the highest concentration of omega-3 fatty acids.
Supplements Protocol for Sarcopenia
Physically active older adults are still susceptible to muscle and strength loss. Supplements that support muscle growth can be incorporated into a sarcopenia treatment protocol for better patient outcomes.
Creatine is an organic acid endogenously produced by the kidneys and liver and found naturally in red meat, seafood, and poultry. Most creatine is stored in skeletal muscles and plays an important role in energy production for muscular contraction. Creatine supplementation, especially when combined with resistance exercise, significantly increases muscle mass and strength. (8, 9)
Dose: 20 g daily for seven days, then decrease to 10 g daily
Whey protein is a highly bioavailable supplemental protein extracted from cow's milk. Regular supplementation with whey protein is associated with anti-inflammatory effects, reduced blood pressure, and muscle growth. (10, 11) For those sensitive to Whey or those who follow a plant based diet, newer studies have shown that plant protein supplementation is also beneficial in fighting sarcopenia.
Dose: 30 g once daily
Vitamin D deficiency is commonly found in sarcopenic patients (6). Research suggests that over half of sarcopenic patients with low vitamin D levels experience falls, and supplementation can reduce the risk of falling by 22% and lower associated bone fracture incidence.
Dose: loading doses to optimize vitamin D status should be determined by serum 25-OH Vitamin D levels; maintenance doses range from 2,000-5,000 IU daily
When to Retest Labs
Patients should expect positive muscle mass changes 12-16 weeks after consistently implementing dietary modifications, routine exercise, and daily supplementation.
Aging and chronic diseases can impair muscle growth and contribute to muscle wasting, leading to decreased muscle mass and strength and an increased risk of falls and bone fractures. Optimizing diet and physical activity to support muscle health can reduce the risk of severe sarcopenia. To learn more about sarcopenia prevention and create a personalized treatment protocol, consult with a functional medicine doctor.
Lab Tests in This Article
1. Ardelijan, A.D., & Hurezeanu, R. (2022). Sarcopenia. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK560813/
2. Bauer, J.M., Morley, J.E., Schols, A.M.W.J., et al. (2019). Sarcopenia: A Time for Action. An SCWD Position Paper. Journal of Cachexia, Sarcopenia and Muscle, 10(5), 956–961. https://doi.org/10.1002/jcsm.12483
3. Walston, J.D. (2012). Sarcopenia in older adults. Current Opinion in Rheumatology, 24(6), 623–627. https://doi.org/10.1097/bor.0b013e328358d59b
4. American Academy of Orthopaedic Surgeons. Effects of Aging. Ortho Info. https://orthoinfo.aaos.org/en/staying-healthy/effects-of-aging/
5. National Library of Medicine. IGF-1 (Insulin-like Growth Factor 1) Test. Medline Plus. https://medlineplus.gov/lab-tests/igf-1-insulin-like-growth-factor-1-test/
6. Hollingworth, T., Oke, S., Patel, H.P., et al. (2021). Getting to grips with sarcopenia: recent advances and practical management for the gastroenterologist. Frontline Gastroenterology, 12(1), 53–61. https://doi.org/10.1136/flgastro-2019-101348
7. USDA. Dietary Guidelines for Americans. https://www.dietaryguidelines.gov/
8. Candow, D.G., Forbes, S.C., Chilibeck, P.D., et al. (2019). Effectiveness of Creatine Supplementation on Aging Muscle and Bone: Focus on Falls Prevention and Inflammation. Journal of Clinical Medicine, 8(4), 488. https://doi.org/10.3390/jcm8040488
9. Santos, E.P.D., De Araújo, R.C., Candow, D.G., et al. (2021). Efficacy of Creatine Supplementation Combined with Resistance Training on Muscle Strength and Muscle Mass in Older Females: A Systematic Review and Meta-Analysis. Nutrients, 13(11), 3757. https://doi.org/10.3390/nu13113757
10. Liao, Y., Peng, Z., Chen, L.Q., et al. (2019). Prospective Views for Whey Protein and/or Resistance Training Against Age-related Sarcopenia. Aging and Disease, 10(1), 157. https://doi.org/10.14336/ad.2018.0325
11. Gilmartin, S., O'Brien, N.M., & Brasca, M. (2020). Whey for Sarcopenia; Can Whey Peptides, Hydrolysates or Proteins Play a Beneficial Role? Foods, 9(6), 750. https://doi.org/10.3390/foods9060750
12. Lang, T., Streeper, T., Cawthon, P. M., Baldwin, K., Taaffe, D. R., & Harris, T. (2010). Sarcopenia: etiology, clinical consequences, intervention, and assessment. Osteoporosis International, 21(4), 543–559. https://doi.org/10.1007/s00198-009-1059-y