Cortisol is the main hormonal end product of stress in the body. It is a steroid hormone, meaning it is made from cholesterol. It moves freely into our cells, and impacts the expression of our DNA by stimulating a receptor on the nuclear envelope. While most hormones have a fairly steady level in the body, cortisol has a diurnal variance, where it is high in the morning, decreases throughout the day except for an after lunch spike, and increases again as we sleep to be high in the morning. Changes in the diurnal rhythm can create significant problems. Too high in the evening, and our brain can't shut down when we're ready to sleep. Too low in the morning, and we can't get out of bed in the morning. No afternoon spike, and we're ready for an afternoon nap. It's not just about the amount of cortisol we have, but also about how much we have when.
In addition to cortisol, there are other hormones that are released in response to stressors. One of these hormones is dehydroepiandrosterone (DHEA). Where cortisol tears into our muscle stores to give us needed energy and is locally destructive, DHEA is protective to a variety of tissues. It generally counteracts the effects of cortisol, most importantly in our brain. DHEA is a regenerative hormone, and is considered by some to be almost a "fountain of youth", since we see decreasing levels of DHEA as we age. Some "anti-aging" doctors regularly prescribe DHEA to their patients because of this. Unfortunately, since this regenerative hormone is also a precurser to many other hormones including estrogens, progesterone, and testosterone, this can be dangerous. Adding a hormone like DHEA without proper testing is like playing Plinko. You add the hormone in at the top, but you never know exactly where it's going downstream. You may end up with excess estrogens in a man or testosterone in a woman, neither of which is desired.
There is a reason DHEA and cortisol are released together. As cortisol has the chance to save our lives, DHEA is there to shorten its duration and protect us if possible. One of the problems we see today, is that long term exposure to stressors will stimulate the body to make cortisol at the expense of DHEA, and we end up with unchecked cortisol and no regeneration afterward. This is another reason some doctors will recommend DHEA supplementally. Again, I caution against this without proper testing to make sure one is really deficient and doesn't end up negatively affecting their other hormones.
Our normal stress response, as defined by Hans Selye, the father of stress research, has three phases to it. Initially, we have an alarm reaction (AR). We then move to a stage of resistance (SR), and finally a stage of exhaustion (SE).
The graphical representation illustrates that as our bodies encounter stressors, we initially have a decreased resistance to them. Think of the first real cold day in November. You know, when it gets down into the low 20's, and we're all complaining about how cold it is, since it was in the 70's just a few weeks ago. Your resistance to cold on that first cold day is less than normal, since you haven't had recent exposure to that stressor. Compare your reaction in November to your reaction in the dead of winter; mid-January when it's been below zero for two consecutive weeks, and we finally have a nice sunny day and climb to a balmy 15. We're rejoicing at how warm it is on that day, yet it's actually colder than it was in November. You're now in the stage of resistance, and you can tolerate more of that stressor than before. If, however, you were to live in a climate where it never ever got warm, and were always cold, eventually, your body's resistance to cold would be exhausted, and you'd enter stage 3. At this point, even 40 seems cold. I see this commonly in my elderly patients. They really don't like cold any more than they like heat. They want a constant 75 degrees all year long. Their resistance to both cold and heat has been exhausted.
How each of us travels through these three phases depends on our individuality and the type of stressor. The stage of resistance can last for decades for some, yet only for a few hours in others. We are each unique, and we have no ability to predict response time..
As we move into stage 2 and 3 though, our response to the stressor changes. Instead of getting as much corticotropic releasing hormone (CRH) from the brain, we get more arginine vasopressin (AVP) instead. Where CRH increases fear related behaviors and reduces reward expectation, AVP increases water retention instead. That means we have the same stressor, but our blood pressure ends up rising instead of our behavior and expectations changing. Repeated or long term exposure of the brain to cortisol also creates significant changes. We see damaging of certain brain structures, shrinking of the brain as a whole, and a sensitization of the brain to cortisol (so it does more damage) and of the adrenals to ACTH (so we get more cortisol released). While we aren't totally sure this is permanent damage to the brain, we are seeing that it is at least somewhat irreversible. Since the structures that seem most affected by cortisol are those that are related to memory, any negative changes are a problem.
Dealing with stress in a positive way is vital to our long term health. We'll continue to discuss how stress affects us and what we can do to help offset the negative effects in the coming weeks.
Look for future blogs that will give more information and insights into improving your health with natural health care. You can also visit my website, like me on Facebook, follow me on Twitter, or listen to my radio show.
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