Elderly individuals are more likely to not only stay in the hospital for longer but also become protein malnourished. Extended hospital stays plus protein deficiency are compounded by a lack of activity which leads to functional declines.

Previous research shows that increasing protein consumption improves nitrogen balance and exhibits an anabolic effect in elderly muscle. Researchers were curious if supplementing with essential amino acids would likewise have a beneficial effect on muscle function.

Participants took either a placebo or 15 grams of essential amino acids 3 times daily during 10 days of bed rest. Researchers measured lean body mass, muscle protein synthesis, and muscle function at the start and finish of the study. 

Results showed that supplemental essential amino acids can help maintain muscle protein synthesis and preserve muscle function, as evidenced by 24-hour muscle protein synthesis (fractional synthetic rate, or FSR) before and after the 10 days of bedrest. 

Conclusion

Boosting protein intake above the recommended daily allowance with essential amino acid supplementation during bed rest or other conditions of inactivity can help preserve muscle function in older adults without impacting appetite. 

Studies have shown that 21% of hospitalized elderly patients meet less than 50% of their daily dietary requirements, including protein, which greatly increases the risk of mortality. While popular protein meal replacements based on either milk or whey protein help to increase protein consumption, they also reduce appetite and overall dietary intake.

Supplementing with essential amino acids offers a solution to that problem, as essential amino acids are calorically minimal and do not increase satiety or affect appetite, and more effectively stimulate protein synthesis.

Citation

Ferrando AA, Paddon-Jones D, Hays NP, et al. EAA supplementation to increase nitrogen intake improves muscle function during bed rest in the elderly. Clin Nutr. 2010;29(1):18-23. doi:10.1016/j.clnu.2009.03.009