Effect of food form on postprandial plasma amino acid profiles in older adults

Abstract

Purpose and MethodsTo assess the effect of food form on the postprandial (PP) plasma amino acid (AA) profile, 10 healthy older adults (5 men and 5 women, age 72 ± 2 y, BMI 26.0 ± 0.9 kg/m2) consumed energy and macronutrient matched test meals (~25% of subject's daily energy need; ~54% CHO, 21% Pro; 25% Fat) in beverage and solid form on separate days. Blood samples were taken during fasting (baseline) and throughout the 4‐hour PP period and plasma AA profiles (pmol/uL) were assessed using high performance liquid chromatography.ResultsThe consumption of each test meal led to an increase in total, branched chain (BCAA), essential (EAA), and non‐essential (NEAA) AA contents over the 4‐h period (time effect; p<0.05). The beverage stimulated a greater increase in total, EAA and NEAA contents, but not BAA content, vs. the solid (effect of food form; p<0.05). The beverage elicited higher plasma AA levels starting at 15 min PP which was maintained for the rest of the 4‐h period. The beverage also resulted in a greater total plasma AA 4‐h area under the curve (p<0.05).ConclusionOlder adults can achieve higher plasma amino acid contents when a protein‐containing food is ingested in beverage form. Future research to explore the utility of this higher amino acid substrate availability on anabolic processes is needed.Support: NIH R01 AG021911, The Solae Company®, Purdue Ingest Behav Res Ctr and Bilsland Fellowship