Sarcopenia – the muscle thief

You may have noticed your grandparents’ (or parents) musculature start to decline as they grow older. This is known as sarcopenia, which translates from Greek as “the loss of flesh.”  Over the age of 50, adults are expected to lose 1-2% of muscle mass per year in addition to significant losses in strength (1,2). Sarcopenia causes a functional decline and physical disability which ultimately results in a reduced quality of life. As the baby boomers age, this problem is beginning to emerge in our population.

The question is: how do we stop it? Unfortunately, it’s not possible yet. The molecular mechanisms behind sarcopenia are unknown and the development of drug-based interventions remains elusive. Current research shows that during sarcopenia  muscles have a compromised regenerative capacity, diminished ability to respond to stress, increased reactive oxygen species production and minor systemic inflammation. Scientists are working to map out the pathways and find appropriate targets (e.g. genes and proteins) that can help reduce muscle wasting. The dilemma is, even if a target is discovered, an FDA approved drug won’t appear in your local pharmacy for 10-20 years. That’s about the length it takes for the average drug to make it from bench to bedside without complications.

Until then, the optimal way to slow muscle loss is through proper nutrition and physical activity. There are four main categories that exercise programs for the aged population should be based around: balance, flexibility, aerobic endurance, and resistance training (3). The exact exercise from each group doesn’t necessarily matter because the goal is to be physically active. I’ll briefly review the four categories and an in-depth explanation may be posted in the future.

Aerobic endurance includes jogging, swimming and biking. This type of exercise has dual benefits because it decreases the risk factors for cardiovascular diseases. Resistance exercise includes working with weights, resistance bands, or any equipment that uses resistance. Studies show that resistance exercise increases muscle mass and strength by elevating protein synthesis rates. It also has an added benefit of increasing bone mineral density, which can help reduce the effects of osteoporosis.

The other two types of exercise go hand in hand. Flexibility can be done in a variety of ways including: static, dynamic, active, or any combination of the three. These types of exercises provide neuromuscular awareness, helping you to coordinate your body. Balance is much like flexibility, such that it can be static or dynamic. In combination these two types of exercises can be used to prevent falls and increase daily physical function. One example of a physical activity that can be done alone or in a group setting is yoga. Research shows that yoga has the ability to increase functional capacity and well-being (6). Likewise, it can improve mobility, balance and reduce falls in an older population (7).

Exercise also plays an important role in brain function. Clinical research suggests that keeping physically active and engaged in moderate to vigorous exercise may be vital to brain health.  Exercise promotes neurogenesis, increased brain volume, and improved cognitive function, which can help the aging brain to retain plasticity (4).

The population of the United States over the age of 65 is expected to double in size within the next 25 years. In addition, the population of people over 85 is the fastest growing segment of any age group (5). While scientists work to develop over the counter treatments for sarcopenia, baby boomers should seek ways to stay mentally and physically active.

 

1. Cruz-Jentoft, Alfonso J., Jean Pierre Baeyens, Jurgen M. Bauer, Yves Boirie, Tommy Cederholm, Francesco Landi, Finbarr C. Martin, et al. “Sarcopenia: European Consensus on Definition and Diagnosis.” Age and Ageing 39, no. 4 (July 2010): 412–23. doi:10.1093/ageing/afq034.

2. Ferrucci L, Guralnik JM, Buchner D, Kasper J, Lamb SE, Simonsick EM, Corti MC, Bandeen-Roche K, Fried LP. Departures from linearity in the relationship between measures of muscular strength and physical performance of the lower extremities: the Women’s Health and Aging Study. J Gerontol A Biol Sci Med Sci. 1997;52:M275–M285.

3. Montero-Fernández, N, and J A Serra-Rexach. “Role of Exercise on Sarcopenia in the Elderly.” European Journal of Physical and Rehabilitation Medicine 49, no. 1 (February 2013): 131–43.

4. Marks, Bonita L, Laurence M Katz, and J Keith Smith. “Exercise and the Aging Mind: Buffing the Baby Boomer’s Body and Brain.” The Physician and Sportsmedicine 37, no. 1 (April 2009): 119–25. doi:10.3810/psm.2009.04.1692.

5. http://www.nia.nih.gov/newsroom/2006/03/dramatic-changes-us-aging-highlighted-new-census-nih-report

6. Akhtar, Pooja, Sujata Yardi, and Murtaza Akhtar. “Effects of Yoga on Functional Capacity and Well Being.” International Journal of Yoga 6, no. 1 (2013): 76–79. doi:10.4103/0973-6131.105952.

7. Tiedemann, Anne, Sandra O’Rourke, Romina Sesto, and Catherine Sherrington. “A 12-Week Iyengar Yoga Program Improved Balance and Mobility in Older Community-Dwelling People: A Pilot Randomized Controlled Trial.” The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences 68, no. 9 (September 2013): 1068–75. doi:10.1093/gerona/glt087.

Dedicated to my grandparents, in hope that they understand my research in the field of muscle biology.