The Influence of Long‐Term Essential Amino Acid Supplementation on Measures of Body Composition in Recreationally Active Older Adults

Abstract

Aging is associated with loss of muscle mass and bone density. Unlike non essential amino acids, essential amino acids (EAA) stimulate protein synthesis. Preliminary data from our group indicate that short‐term EAA supplementation can improve muscle mass in sedentary elders. However, the effect of long‐term EAA supplementation on body composition in recreationally active older adults is unknown.The purpose of this pilot study is to determine if supplementation with EAA can improve indices of body composition in older, recreationally active subjects.We have currently enrolled 12 healthy, recreationally active older (50–70 years) subjects who have been randomly assigned to receive either 15g of EAA (n= 6, age= 61±3, BMI= 25.3±0.8) or an isonitrogenous, isocaloric placebo (alanine; n=6, age= 63±4, BMI= 25.4±1.2) daily for one year, while maintaining their usual physical activity level. At baseline and every three months body composition was measured by DEXA.Preliminary data from six subjects indicate that bone mineral content tended to increase in the EAA group after one year of treatment (Baseline: 2019.1±104.6 grams, 12 months: 2094.5±116.7 grams, P=0.06), while other body composition parameters do not yet display significant changes.In conclusion, these preliminary data suggest that 12 months of supplementation with essential amino acids may improve bone density in recreationally active, older adults.Supported by NIA P30 AG024832 and R01 AG030070