Originally Posted by
Robert Santana
"Digest" is probably the better word. Older folks often have achlorohydria, where the stomach make less hydrochloric acid and thus they cannot effectively denature proteins as well as a young person. Therefore, they are unable to extract the amino acids, which leads to less protein absorption. I don't know any studies off hand but achlorohydria is heavily documented in the elderly and the downstream effects are pretty straightforward and well established at this point.