BCAAs (Branched Chain Amino Acids) include the three essential amino acids leucine, isoleucine, and valine. Basically, they help the body process protein and can modulate insulin secretion. They have been shown to preserve both performance and body composition when taken under certain conditions (i.e. when combined with a strength training program and/or taken with calorie-restricted diets). Without knowing your diet or exercise particulars, it's difficult to predict what outcomes BCAA supplementation could produce. Nevertheless, the research for older adults is promising, even for non-athletes. One particular study of men and women 65 to 79 years old showed that BCAA supplements improved leg muscle strength, which generally declines with age.*

*Paddon-Jones D, Sheffield-Moore M, Katsanos CS, Zhang XJ, Wolfe RR. Differential stimulation of muscle protein synthesis in elderly humans following isocaloric ingestion of amino acids or whey protein. Exp Gerontol. 2006 Feb;41(2):215-9. Epub 2005 Nov 23