Having problems with message search?
Hi Paul,
You asked: "Any physiological hypotheses as to why insulin might increase cortisol levels? Seems counterproductive seeing as they have opposite actions on blood glucose levels...."
This is all blue-sky hypothesizing, with very little evidence, but here goes.
I think it has something to do with the fact that cortisol is, from an evolutionary standpoint, very well preserved. It developed early in our evolution, and it is involved in many functions. Any change to cortisol would be difficult for Mother Nature to accommodate, so other hormones have evolved to modify the behavior of cortisol without having to actually change cortisol.
Cortisol is often called a counterregulatory hormone because it blocks insulin, but insulin may have evolved later. Many kinds of cells do not need insulin to utilize glucose. Insulin is a counterregulatory hormone for cortisol, at least as far as liver and muscle cells are concerned.
I read somewhere, probably in one of the books hypothesizing about what our ancestors ate, that we were hard-wired to eat all of the carbohydrates we could find during the brief periods when they were available. Sounds reasonable, but large parts of tropical Africa must have had fruits of some kind available all of the time. There wouldn't be much need to gorge on carbs. The appestat and lipostat probably evolved to keep our ancestors from getting so roly-poly they couldn't escape from predators.
As our ancestors moved north, then it would have become more important to eat every bean and berry they could find when they were available. Something would have to override the appestat and lipostat for several weeks every fall. Yudkin's small (and apparently lost) research project made me think that having insulin raise cortisol levels might be a cheap evolutionary trick for fattening us up in the fall.
Checking the plausibility of this idea and working out the details would take more time and effort than I am likely to ever put into it.
I'm working hard on a major update of my website, then I'm going to do some recruiting for the infection-cortisol group. Russ
----- Original Message -----From: PaulTo: Russ FarrisSent: Monday, July 14, 2008 5:45 PMSubject: Re: Carbs & cortisolAny physiological hypotheses as to why insulin might increase cortisol levels? Seems counterproductive seeing as they have opposite actions on blood glucose levels....
Offline 
Send Email