It depends on many things, but Poliquin's references that it improves the circulatory system seem true for young healthy men. There are also powerful insulin sensitivity effects that will allow any insulin secreted to work that much the better.
This seems to be true for young men, and not older (50+):
^ Same researchers as one of Poliquin's references.
The last reference is available as full text (Age: 23+/-1y):