Amino Acids and Muscle Loss with Aging
Amino Acids and Muscle Loss with Aging

Amino Acids and Muscle Loss with Aging

Overview

Age-related muscle loss, or sarcopenia, is a natural part of the aging process, but one that can also be attenuated with targeted nutritional intervention. Sarcopenia greatly reduces quality of life and shortens life expectancy when not managed. Although the mechanisms of sarcopenia are not entirely understood, science suggests that older muscle has a subdued response to muscle-building (anabolic) stimuli and that older adults are probably not getting the protein they need to build and maintain muscle.

Trial Length

Variable

Number of Subjects

52

Gender

All genders

Age Range

60 and over

The Goal

To examine available scientific evidence to determine the role nutritional intake and anabolic stimuli have on protein metabolism in the elderly.

The Results

A review of the literature shows that, although aged muscle becomes less responsive to factors that trigger the muscle-building response, such as insulin, it is still responsive to increased doses of protein and amino acids, particularly the essential amino acids (EAAs), including the branched-chain amino acids (BCAAs).  

Basal values of muscle protein synthesis and breakdown in normal young and elderly during oral amino acid intake.

Researchers believe that the ability of EAAs to activate muscle protein synthesis is likely due to the effects of the BCAA leucine to jumpstart mRNA translation. Studies show that adding extra leucine to an essential amino acid supplement may help overcome any anabolic resistance in older muscle, thereby helping to prevent and treat sarcopenia. 

 

The Conclusion

Researchers determined that supplementation with essential amino acids, especially with added leucine, can help restore and maintain muscle mass in older adults, and that when developing nutritional strategies to counteract muscle loss, inefficient sources of energy, such as the nonessential amino acids and carbohydrate, should be eliminated.

The Why?

Sarcopenia causes progressive muscle loss that impairs mobility, increases the risk of falls and fractures, and is associated with higher morbidity and mortality. Developing nutritional strategies to help mitigate the effects of sarcopenia, such as targeted essential amino acid support, can help enhance quality of life and overall health outcomes.

Citation

Fujita S, Volpi E. Amino acids and muscle loss with aging. J Nutr. 2006 Jan;136(1 Suppl):277S-80S. doi: 10.1093/jn/136.1.277S. Review. PMID:16365098