ABSTRACT
This investigation compares the levels of plasma kinetics of plasma essential amino acids (EAAs) after ingestion as free-form EAAs (FEAAs) or EAAs as components of dietary protein (DPEAAs), in eighteen healthy individuals, nine elderly (85 ± 6.7 years; 4 male) and nine young (28.7 ± 7 years; 3 males). For two consecutive days, each subject ingested EAAs in the form of (FEAAs) or (DPEAAs) in a random alternate pattern. Five minutes before EAA ingestion (baseline) and 30, 60, 90, 150 and 270 min after, venous blood samples were taken to determine the concentrations of EAAS (micromol/L). In both groups, ingested FEAAs compared to DPEAAs led to faster increase in plasma EAA levels at 30-150 min (p < 0.0001). Moreover, the increased plasma EAAs disappeared faster after FEAA compared to DPEAA. These results may be important in those subjects who have high requirement both for EAAs substrates and anabolic efficiency.
