With the increase in the age that is inevitable, there will be decline in all major metabolic processes in the body. The foremost reason for this is the loss of muscle mass, which is known as ‘sarcopenia’
Sarcopenia
Sarcopenia is a progressive loss of muscle mass with increase in the age, which can lead to muscle weakness, low strength, and frailty. This leads to increased injuries due to falls, and also hampers their regular activities.
Sarcopenia starts when a person doesn't have an adequate or optimal intake of all nutrients from their food, along with sedentary lifestyle. As one ages, the muscle mass starts to decline at 0.5-1% per year at 40 years of age onwards. More severe sarcopenia happens from 60 years onwards. This is due to the decline in the hormones such as testosterone (men), estrogen (post-menopausal women), growth hormone and others. Moreover, fat mass also starts to accumulate due to low nutrition and also inactivity due to mobility issues.
Any older person with age-related issues approaching a medical professional, to make sure that they know the amount of muscle mass, fat mass and bone density with the help of various techniques (such as DEXA scan). It will be helpful to detect the extent of loss of muscle, which will be used to recommend the protein quantity.
Protein recommendations
In a healthy adult population, it is generally recommended an adequate intake of dietary protein of 1.2-1.8 g/kg/day to increase or maintain the muscle mass. As the person becomes older, the minimal recommended protein intake is 0.8 g/kg/day to help them preserve. When they progressively increase the protein intake, the anabolic process can be enhanced and the muscle mass will be increased. Though, aging related outcomes cannot be avoided fully, their occurrence can be extended.
Since muscle building process is slow or low (anabolism) due to aging, it is important to include essential amino acid ‘leucine’ containing foods. Leucine is one of the 9 essential amino acids, and also one of the branched chain amino acids (BCAA) that plays a role in the muscle protein synthesis. It is observed that higher quantities of leucine (2.8g) as compared to the normal quantity (<1.7g) of the total essential amino acid content (6.7 g) (Fujita et al., 2006). With this conclusion, it is also necessary to know the proper nutritional intervention for elderly people to either maintain or restore the muscle mass.
Also, there is increasing evidence that physical activity, specifically weight training or resistance training, slows down the sarcopenia with aging (will be discussed in a separate topic).
Conclusion
It is important to educate elderly people to start incorporating the adequate amount of complete protein into their diet along with a structured resistance training plan to avoid injuries.
References
- Beasley, J. M., Shikany, J. M. and Thomson, C. A. (2013) ‘The role of dietary protein intake in the prevention of sarcopenia of aging’, Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition, 28(6), p. 684. doi: 10.1177/0884533613507607.
- Fujita, S. and Volpi, E. (2006) ‘Amino acids and muscle loss with aging’, Journal of Nutrition, 136(1). doi: 10.1093/JN/136.1.277S.
- Paddon-Jones, D. et al. (2008) ‘Role of dietary protein in the sarcopenia of aging’, The American Journal of Clinical Nutrition, 87(5), pp. 1562S-1566S. doi: 10.1093/AJCN/87.5.1562S.
