Nutritional Considerations for Minimizing Sarcopenia among Older Adults

The United States has an aging population, and with that comes an increasing propensity toward health concerns. It is well documented that older age is associated with high risk for cardio-metabolic disease as well as a decline in movement capabilities. Clearly, engaging in appropriate exercise is critical to the maintenance of independence as well as a greater quality of life among older adults. Research demonstrates a lack of physical activity during the later decades of life strongly contributes to the estimated 10-30% loss of biological function experienced over this period. It should be understood that this functional decline can also be related to the presence of disease, specific genetic and environmental factors, poor mental health, and pre-existing injuries such as low back pain. Sarcopenia is defined as an age-related loss of muscle mass with associated reductions in strength and power. The loss of protein from the heavy myosin chains of muscle fibers, alongside neural and connective tissue decline collectively serve as the primary culprits behind musculoskeletal system deterioration among individuals over 60 years of age. The mechanisms behind this process of muscle wasting (which can further promote inactivity) include hormonal changes, a loss of fast-twitch fibers, glycation of bodily proteins (impairs function of cells), and insulin resistance.

Nutrition also has a significant part to play in age-related functional decline. A recent study published in Osteoporosis International sought to identify a number of related factors, and how they may contribute to sarcopenia. The role of dietary protein, acid-base balance, vitamin D, calcium, and other select nutrients such as the B-complex vitamins were evaluated via an extensive literature review.

The following recommendations/considerations were made based on a review of current research:

• A minimal protein intake equaling 1.0-1.2 g/kg of body weight per day may be optimal for older adults to maximize muscle function, regeneration and recovery
• A moderate inverse relationship between vitamin D status and muscle strength was found, indicating a need for adequate intake to maintain optimal bone and muscle function
• Chronic ingestion of acid-producing diets appear to have a negative impact on muscle performance, indicating acid-base balance may be integral to minimizing muscle wasting
  • Artificial sweeteners, excess animal protein intake, alcohol, select fruits and vegetables, most processed grains, and select condiments and spices are known to be acid-promoting
  • Signs of high systemic acidity: fatigue, breathlessness, frequent muscle pain/cramping
• Decreases in vitamin B12 and folic acid intake may also impair muscle function through their action on homocysteine (has an impact on collagen in bone and other connective tissues)

It is clear that regular weightlifting, power training, ROM activities, and specialized nutritional strategies should be used when training older adults to minimize muscle loss and the consequent decrease in overall function. Resistance training should emphasize re-establishing a functional skeletal position and focus on muscle balance. One area of emphasis is strengthening the posterior chain, particularly the muscles that act on the humerus and scapula while lengthening the anterior chain as hip flexors and abdominals become tight due to gravitationally influenced migration into flexion. Power training should aim to recruit fast-twitch fibers but be modified to ensure safe movements during higher-velocity movement. Emphasis should be placed on the concentric aspect of the movement which can include rapid chair stands, concentric-only MB throws, and bodyweight movement drills for those at higher risk. Be cautious with individuals suspected of osteoporosis as the vertebrae, hip and wrist are sensitive to injury.

It can be hoped that future research will provide greater data related to specific quantities of key nutrients essential to limiting sarcopenia, so that these intake guidelines may be combined with an appropriate resistance training program to an effect of enhanced quality of life among the elderly.