Have you ever told anyone that cortisol is a stress hormone that comes from the adrenal glands?
We have, too, and it turns out we were wrong.
(Worst feeling as a practitioner, ever.)
Let's not make that mistake again.
So, why is it wrong?
Well, for one, it turns out cortisol is made in places OTHER than the adrenal glands. And according to research, in enough quantity to potentially impact total circulating cortisol levels.
In other words, when you test serum cortisol, you don't really know where that cortisol is coming from.
Feeling superior because you only test salivary cortisol?
Not so fast. Salivary samples may be even less likely to measure cortisol coming from your adrenal glands.
So, that nice little story you've been telling your patients? It's not accurate.
What tissues make cortisol?
Well, skin for one. Skin not only makes cortisol, but it actually has its own HPA axis. It appears that skin makes its own CRH, ACTH, and cortisol!
How much does non-adrenal cortisol contribute to overall levels?
It's difficult to say, but check out this study. In it, eight healthy men were recruited and fed isocaloric macronutrient shakes over a few days. They had their cortisol levels tested after drinking the shakes.
Researchers found that cortisol levels went up fairly equally after each macronutrient drink. No biggie. It's where the cortisol came from that gets interesting.
After the fat shake or the protein shake, researchers found that roughly 70-80% of the cortisol came from the adrenal glands, with 20-30% of cortisol coming from elsewhere. That's significant, but not the most vital part.
With a carbohydrate shake, only 50% of serum cortisol came from the adrenal glands, and 50% came from elsewhere.
In other words, not only do macronutrients impact cortisol levels, but also where cortisol comes from.
Feeling insecure about running cortisol panels to determine whether someone's adrenals are fatigued or not, now?
You should be.
Listen, there is A LOT more to most stories than we are telling in the Functional Medicine world.
Adrenal physiology is not as simple as the soundbites that are circulating. It sounds easy to collect saliva or urine in a test tube to determine whether "adrenal fatigue" is to blame for all of your woes. But it's not accurate.
Get the full story in our new workshop, "How to Evaluate Adrenal Fatigue on A Blood Chemistry."
In it we will be covering: