May/June 2012

Nutrition’s Role in Sarcopenia Prevention

By Becky Dorner, RD, LD, and Mary Ellen Posthauer, RD, LD, CD
Aging Well
Vol. 5 No. 3 P. 18

Physicians and other healthcare professionals can take a proactive role in recommending ways to prevent patients’ loss of muscle mass.

Approximately 45% of older adults in the United States are affected by sarcopenia, a number that will continue to increase as the population ages.1 Sarcopenia, the Greek term meaning “poverty of the flesh,” is the progressive loss of muscle mass, function, quality, and strength driven by the aging process. This loss of muscle mass often leads to diminished strength and decreased activity levels and can contribute to mobility issues, osteoporosis, falls and fractures, frailty, and loss of physical function and independence.2 This article provides general information about this condition, with a focus on the nutrition considerations to help healthcare professionals recognize ways to assist patients in preventing sarcopenia.

It is estimated that sarcopenia affects 30% of people over the age of 60 and more than 50% of people over the age of 80.3 Between the ages of 30 and 60, the average adult will gain 1 lb of weight and lose 1/2 lb of muscle yearly, a total gain of 30 lbs of fat and a loss of 15 lbs of muscle. After the age of 70, muscle loss accelerates to 15% per decade. People who are obese and also have sarcopenia (sarcopenic obesity) seem to have worse outcomes than those who are not obese.4,5 And older adults who must be on bed rest can experience dramatic physical declines due to rapid loss of both muscle mass and strength.

Estimates indicate that 20% of older adults in the United States are functionally disabled, and the risk of disability is 1.5 to 4.6 times higher in older adults with sarcopenia than in those of the same age with normal muscle.2 Pathological sarcopenia is associated with a very high rate of disability.6 The weakness that accompanies sarcopenia can dramatically increase the risk of falls for older adults, and one-half of all accidental deaths among people over the age of 65 are related to falls.7 There is even some evidence that sarcopenia is related to metabolic problems, including insulin resistance, type 2 diabetes, and obesity.8

The economic burden of related healthcare expenditures for sarcopenia in the United States is estimated to be $18.5 billion annually (or $900 per person per year).1,9 The cost of treating men with sarcopenia is $10.8 billion, while the cost of treating women is $7.7 billion. The greater decline in men’s muscle mass is attributed to hormonal factors, including a decrease in growth hormone and testosterone levels.10 Janssen and colleagues estimated that a reduction of sarcopenia of just 10% would save $1.1 billion in healthcare costs.1

Factors that accelerate an older adult’s loss of muscle mass include decreased physical activity, testosterone and growth hormone deficiency, possibly mild cytokine excess, and the stress response.10 Physiological anorexia, decreased caloric intake, and weight loss are all related to aging which, in turn, is associated with a decline in muscle mass and increased mortality.11,12 On average, older adults consume fewer calories and protein than younger adults. While the exact cause of the decreased intake is unclear, several theories have been advanced including lower muscle mass resulting in lower physiological nutrient needs.13

Risk factors for altered nutritional status include the following:

• sensory changes in the ability to taste food;

• refusal to consume meals related to restrictive therapeutic diets;

• decreased ability to eat independently related to physical and/or cognitive decline;

• insufficient availability of food or fluids;

• environmental factors such as dining room atmosphere;

• decline in instrumental activities of daily living (eg, food procurement and preparation);

• adverse consequences of medications;

• depression or social isolation due to the loss of a spouse or friends;

• gastrointestinal disorders such as gastroesophageal reflux disease, chronic diarrhea, or constipation; and

• diseases such as Parkinson’s, advanced lung or heart disease, or repetitive movement disorders (eg, pacing, wandering, rocking).

Nutrition Screening
Early screening to identify individuals at nutritional risk for unintended weight loss and undernutrition or malnutrition is essential. Physicians, healthcare facilities, and agencies should use a validated nutrition screening tool. The Mini Nutrition Assessment Short Form (MNA-SF) has been validated in both the community and healthcare settings specifically for adults over the age of 65.

The MNA-SF focuses on six variables that together identify malnutrition in older adults. The first three variables evaluate indicators of past nutrition status (weight loss), present nutrition status (body mass index or calf circumference), and potential future nutrition problems (appetite). The last three variables assess important age-related factors that negatively impact nutrition in the elderly (disease, dementia or depression, and immobility). Low MNA-SF scores correlate with a decline in functional ability, cognitive impairment, and increased frailty in older adults.14

The MNA-SF screening can be completed in approximately five minutes and is a stand-alone tool to identify malnourished older adults. Simple directions for performing anthropometric measures are available in the guidelines that can be downloaded from the MNA website at www.mna-elderly.com.

Other validated screening tools include the Malnutrition Screening Tool and the Malnutrition Universal Screening Tool. However, these tools are not widely used in this country.

Nutrition Care Process
If the nutrition screening process determines an individual is at high risk for unintended weight loss, undernutrition, or malnutrition, a referral should be made to a registered dietitian (RD). The RD should follow the Academy of Nutrition and Dietetics (formerly the American Dietetic Association) Standardized Nutrition Care Process of assessment, diagnosis, intervention, and monitoring/evaluation.

A comprehensive nutrition assessment includes a review of the nutrition screening tool, the medical record, and an interview with the individual patient or resident. The Subjective Global Assessment is a validated nutrition assessment tool. However, this is not widely used in the United States.15,16 Because there are few validated comprehensive nutrition assessment tools currently available, the assessment should include some basic information such as the following17:

• preadmission illness, medical history, diagnosis, and recent changes in condition;

• risk factors or signs or symptoms of undernutrition, malnutrition, dehydration, unintended weight loss, and pressure ulcers; 

• height, current weight, usual body weight, weight history, and significant changes in weight (> 5% in 30 days or > 10% in 180 days);

• current food and fluid intake adequacy compared with calculated nutritional needs;

• eating ability (able to feed self, requires assistance, needs total assistance);

• interview with the individual and/or family or staff for food preferences and tolerances;

• medications that may affect food or fluid intake or tolerance (eg, food-medication interactions);

• other factors that may impact nutritional status (eg, chewing/swallowing ability, gastrointestinal problems, depression);

• current nutrition interventions (eg, food or dining interventions, oral nutritional supplements); and

• monitoring and evaluating nutritional status and outcomes.

In addition to these factors, nutrition-focused physical examination should include an inspection of the body to determine information regarding the individual’s nutritional status. Visual assessment of overall appearance can help identify underweight or cachexia, muscle wasting, abdominal distention, edema, and/or weakness in the extremities, all of which may indicate protein energy malnutrition. Oral examination may reveal issues with chewing and/or swallowing. Skin examinations help assess for the presence of ulcers, skin tears, bruises, turgor, or dryness .17

Biochemical data analysis may help clinicians evaluate overall health issues; however, care must be taken when interpreting lab values for use as nutritional markers. Although markers of protein status, such as albumin and prealbumin, may assist the clinician to establish overall prognosis and severity of illness, they are not accurate markers of protein or nutritional status.18

It is important to review laboratory values for anemia and/or dehydration. When anemia is present, the blood has reduced oxygen-carrying capacity, which can lead to various side effects and negative consequences such as lower endurance, impaired temperature regulation, decreased immune function, increased rates of infection, impaired cognitive functioning/memory, and possibly increased mortality in older adults.19 Dehydration can have serious consequences for older adults, including decreased functional ability, predisposition to falls and infections, fluid and electrolyte imbalances, disorientation, and even death.

The care plan should be developed based on the assessment and the risk factors identified, and the goals should be measurable. Interventions should be individualized, aggressive, and revised as often as needed based on responses, outcomes, and needs.

Key Nutrition Recommendations
In 2008, the Society for Sarcopenia, Cachexia, and Wasting convened an expert panel to develop nutritional recommendations for sarcopenia prevention and management. For preventing and treating this condition, protein and energy intake are key components, along with both resistance and aerobic exercise.

Protein
Older adults historically are at risk of protein intake below the Recommended Dietary Allowance (RDA) for healthy adults (0.8 g/kg/day). Older adults fail to ingest the highest acceptable macronutrient distribution for protein of 35% of energy intake. One study of adults over the age of 50 noted that 27% to 41% of women and 15% to 38% of men consumed less than the RDA for protein.20

Several studies illustrate the correlation between protein ingestion and muscle mass. Ingestion of protein-deficient meals fails to stimulate protein synthesis because the availability of blood amino acids is not increased.21 Essential amino acids’ prime responsibility is the regulation of protein synthesis, and leucine seems to be the most beneficial amino acid.22 Leucine is a precursor for protein synthesis and stimulates the specific intracellular pathway associated with muscle protein synthesis.

Metabolic changes in older adults result in the production of less muscle protein than for younger adults who consume the same amount of dietary protein. Studies indicate that an amino acid mixture of 30 g per meal produced protein synthesis similar to younger people.23 The expert panel recommended a total protein intake of 1 to 1.5 g/kg/day with equal amounts of protein consumed at breakfast, lunch, and dinner.24 This would be equivalent to 69 to 102 g/day for a person weighing 150 lbs (23 to 34 g per meal).

Supplementing the diet with whey protein is beneficial because whey protein delivers the correct amino acids in proportion to the ratio of skeletal muscle. Whey protein supplementation stimulates an important mechanism that preserves muscle mass by creating and maintaining a high concentration of essential amino acids in the blood. Paddon-Jones and colleagues noted that whey protein supplementation (15 to 20 g) increased the muscle-strengthening effects of resistance exercise.25 Creatine may improve the effects of exercise on sarcopenic individuals, but additional studies are recommended.24

Vitamin D
Vitamin D deficiency is the most prevalent nutritional deficiency for older adults regardless of race or ethnicity. Levels of 25-hydroxyvitamin D (25(OH)) decrease with age. Depleted vitamin D levels are associated with low muscle strength. Supplementation of vitamin D in individuals with low levels increases muscle strength. 25(OH) vitamin D levels should be measured in all sarcopenic individuals and vitamin D supplementation in doses sufficient to increase levels above 100 nmol/L should be given as an adjunctive therapy.24 Dosages of 50,000 IU of vitamins D2 or D3 per week are acceptable.

Clinical Strategy
Tips for Adding Protein
• Add cheese to vegetables, salads, potatoes, rice, noodles, and casseroles.

• Add hard-cooked eggs to salads.

• Consider Greek yogurt alone or add to fruit and cereal.

• Supplement diet with high-protein bars or a fruit smoothie made with milk or yogurt.

• Add peanut butter to sandwiches, toast, crackers, or muffins or use as a dip for vegetables and fruit.

• Add powdered milk to cream soups, mashed potatoes, casseroles, puddings, and milk-based desserts.

• Add a scoop of powdered milk, whey protein, or powdered commercial supplement mix to each cup of regular milk (2 cups) daily. These can also be added into hot cereal.

• Select commercial supplements with high-quality protein.

• Add nuts, seeds, or wheat germ to casseroles, breads, muffins, pancakes, and cookies or use nuts, seeds, or wheat germ to top fruit, cereal, ice cream, and yogurt or in place of breadcrumbs.

• Add beans (eg, navy, kidney, pinto, black) and lentils to soups, casseroles, or salads.

Physical Activity
Nearly all older adults can benefit from resistance and strength training to increase muscle strength, improve functional ability, or prevent further decline. There are four components of physical activity that are important for a well-balanced exercise plan. Resistance exercise, in particular, has been shown to decrease frailty and improve muscle strength in very elderly adults. Exercise is recommended on most days of the week, but a minimum of three times per week is recommended to slow muscle loss and prevent sarcopenia.17

Overall, endurance exercises improve the cardiovascular and circulatory systems (low-impact exercises). Strength training reduces sarcopenia, builds muscle, and possibly prevents osteoporosis. Alone and in combination with nutritional supplementation, strength training increases strength and functional capacity.26 Balance exercises such as tai chi or something as simple as standing on one leg with eyes closed (possibly while holding onto a stationary object) can help prevent falls. And flexibility exercises such as yoga or stretching can help older adults recover from or prevent injuries or falls.27

Nutrition and exercise together have a synergistic effect that helps combat malnutrition, increases strength, and promotes well-being. Encourage physical activity and suggest age- and ability-appropriate exercises, including walking and strength training. Refer patients to a physical therapist to assess range of motion, strength, and endurance and to determine the need for assistive devices such as canes, walkers, grab bars, or shower chairs. Determine whether an elder can benefit from continued physical therapy, occupational therapy, or strength training and refer to social services for a home environment assessment as appropriate.17

Hormone and Drug Therapies
Testosterone therapy for men with low testosterone levels has been linked to increased muscle mass; however, it has not been associated with improved functional performance or a reduction in mortality. In addition, cardiac complications and prostate cancer are potential risks of testosterone therapy. More research is needed to determine whether therapy is safe relative to the benefits it produces.

Growth hormone has not been shown to reverse sarcopenic symptoms in older adults, and it may create profound side effects.  Angiotensin-converting enzyme inhibitors show some promise in treating muscle atrophy and reducing inflammation. Selective androgen receptor modulators are a promising new class of drugs that may act similarly to testosterone without the negative side effects. However, further study is needed.1,28

Final Thoughts
It’s more effective to adopt strategies designed to prevent or slow the progression of sarcopenia than it is to try to treat the condition in elderly patients. Recommending dietary modifications, nutritional supplements, exercise, and possibly hormone replacement therapy can be appropriate steps to combat muscle deterioration. Maximizing muscle mass can improve older adults’ functionality, strength, endurance, and general health.

Note: Parts of this article are excerpted from Diet Manual: A Comprehensive Nutrition Care Guide published by Becky Dorner & Associates, Inc.

— Becky Dorner, RD, LD, is known as one of the nation's leading experts on nutrition and long-term healthcare. She currently serves as speaker of the House of Delegates for the Academy of Nutrition and Dietetics.

— Mary Ellen Posthauer, RD, LD, CD, is president of MEP Healthcare Dietary Services Inc in Evansville, Indiana. She was a member of the 2008 Society for Sarcopenia, Cachexia, and Wasting Disease expert panel that developed nutrition recommendations for sarcopenia and was a contributing author to “Nutritional Recommendations for the Management of Sarcopenia,” an article that appeared in the Journal of the American Medical Directors Association.

References
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26. Mead Johnson Advisory Board for Geriatric Health and Nutrition. Recuperative Powers of Nutrition: Resistance, Recovery, Rehabilitation Monograph. Mead Johnson Nutritionals, Mead Johnson & Company: 2003.

27. Falls and older adults. NIH Senior Health website. http://nihseniorhealth.gov/falls/aboutfalls/01.html. Accessed June 14, 2010.

28. Sarcopenia & its costs. Aging in Motion website. http://www.aginginmotion.org/resources. Accessed March 14, 2012.