Welcome to the fourth and final installment of this mini-series on cortisol. You may know cortisol as "the stress hormone", but if you have been following along, by now you realize it does a lot more. You may be wondering: if cortisol helps regulate... pretty much everything... why does it have this bad reputation?
And if you are just jumping in, here are parts I-III:
So is it a lie that cortisol is bad?
Some of the cortisol-stigma comes from the time before we knew about the rhythm of cortisol. To early researchers, time of day (which causes >70% of the variance1) was "nuisance variation." A nuisance to measure, but not a nuisance to the body! Strong daily variation is what we want to see.
You may be wondering: if cortisol helps regulate... pretty much everything... why does it have this poor reputation?
As it turns out, a flattened cortisol slope (lack of variance) is the problem when it comes to cortisol. Think about what would would happen if:
cortisol levels didn't rise in the morning (no morning cheer)
cortisol levels didn't fall in the afternoon (no evening sleepiness)
cortisol levels rose in the evening (evening insomnia)
cortisol levels rose in before the early morning (middle of the night wakefulness)
Any of these scenarios would look similar if you plotted them on a chart: a flattened cortisol slope.
A flattened cortisol slope is a sign that negative states are on the way, mentally and physically. A flattened slope can come with too little cortisol, or too much, or the right amount but at the wrong times. Besides anxiety–which can be correlated with a super high spike in the morning—most cortisol problems wouldn't look "high" at any single reading. This is why cortisol levels can only predict other outcomes if measured across the day.
Here is a non-comprehensive list of negative outcomes associated with flattened cortisol slopes.
These are not all, but instead, the ones most often studied in research:
all-cause mortality
anxiety symptoms
depression
cancer
cardiovascular disease
fatigue
immune and inflammatory disorders ←THIS IS THE MOST HIGHLY CORRELATED
mental illness
obesity
and other physical and mental health problems
According to Adams, et al:
The broad array of health outcomes with which flatter [diurnal cortisol slopes] were associated argues against very specific disease processes, and towards some form of more general, shared mechanism common to multiple disease states.
They go on to introduce a new theory about cortisol problems. They call it stress-related circadian dysregulation (SCiD).
Importantly, the SCiD theory implies that in any intervention, it is the righting of rhythms that is important, more so than the righting of levels. Any therapies, including pharmacologic ones, should have the restoration of expected circadian rhythms as a key goal.
And now, this is starting to sound a lot like what is coming to light about all mental disorders from birth to death:
Cortisol is not only controlled by the circadian rhythm, but is itself a means the body uses to stay in rhythm. What this means is that we need to work doubly with cortisol.
We need to right our rhythms to right our cortisol
We need to right our cortisol to right our rhythms
Keep reading for more on what the experts recommend along those lines.
Ways to strengthen the cortisol rhythm (or, how to steepen daily cortisol declines)
Here are some of the suggestions from the authors of the Slopes paper:
Better sleep
Better mood
Reduced stress
Better control of inflammation
As we know, sleep is a function of the circadian rhythm (not the other way around). Healthy inflammation and immune responses, likewise, depend on strong circadian rhythms. And, from a mental health perspective, mental wellbeing also depends on strong circadian rhythms.
recently did a post about mood and stress. It included some fascinating information about cortisol in whales (as measured in their earwax!). And lots of tips for reducing stress. Some of the ideas I resonated most with include:Leave enough time for sleep. They suggest 7-8 hours per day. From a circadian perspective, that requires 10 hours of near-darkness each night. By near-darkness, I mean under 2-10 lux, depending on how light-sensitive you are.
Eat healthy meals every day. They cite DHA in particular, which is a brain-protector. Folate, imperative for healthy circadian rhythms, also depends on DHA as a cofactor.
Practice deliberate, physical activities. Joyful movement is a key cited by many as vital for wellbeing, and it always helps me! From a cortisol view, more intense exercise is best after the morning cortisol surge is over but well before bedtime. This can reduce heart attack and injury risk.
Take part in community. Very helpful—being in community, especially in-person, but also online if in a good one.
To read the full IF post (they have more tips, not to mention that interesting bit about the whales), go here:
And for righting circadian rhythms, I'd also direct you to my early post, Start Here: A guide to helping people stabilize and strengthen their circadian rhythms.
I hope you enjoyed this series on cortisol and that it helped you see this important hormone in a new light. Post a comment or hit reply to let me know what this sparked for you!
Thank you for the shout out of the IF Insider. I'm going to dive in to your cortisol series.