*Disclaimer: The written article is based on a summary of existing literature on the topic of infrared saunas. The article is for educational purposes and the information provided below cannot be taken as a promise to help with acute health problems or diseases.
The claims in the article are backed by 19 scientific references. All references are numbered. You can access the text of the reference by clicking on the number.
I listened to an excellent podcast episode by Dr. Rhonda Patrick and Dr. Ashley Mason on drug-free treatment approaches to treating depression, insomnia, and overeating (1).
Keep in mind that if you have "depression", it doesn't mean that you feel badly after work one night or even a week. If I simplify the pathological condition called "Major Depressive Disorder", you're feeling bad all the time for a longer period of time.
In this blog post, I'll mainly talk about the first benefit - drug-free approaches to counter depression. Specifically, Dr. Ashley Mason talked about "Whole-Body Hyperthermia" (WBH) or creating "hyperthermia" (overheating) in the entire human body. Saunas, and specifically infrared saunas, are an excellent means to accomplish that goal, and hence, I decided to dig a little deeper into the topic.
Also, let me explain a bit about my methodology in this blog post:
Rather than provide my own thoughts, which I do in many blog posts on this website, I've instead opted to list the lessons I got from listening to this amazing podcast.
- Firstly, what I hope to accomplish with this work is to simplify some of the scientific jargon for the non-expert reader. The podcast and theory behind it are pretty complex so I'd like to simplify how it's communicated.
- Secondly, I also try to provide people who'd rather read than listen to content with a second alternative in the written form.
- Thirdly, regarding some parts of the argument I've added my own interpretation on the topic. I've added some of my suggestions at the end of this blog post.
Let's begin with the beginning - the theory behind the podcast episode:
Dr. Ashley Mason's On Why Whole-Body Hyperthermia Implies Infrared Sauna Depression Benefits
Below I've listed several lessons from listening to the Dr. Ashley Mason podcast episode, where she was interviewed on the "Found My Fitness" podcast #67 by Dr. Patrick.
Before digging deeper into the theory, let's consider some definitions. Whole Body Hyperthermia (WBH) is different from sauna use in one regard, in that the former uses very intense heat to exhaustion, while the latter may not necessarily do so.
You can use an infrared sauna in a very relaxing way, such as with 15 minutes sessions alternated with cold showering that prevents you from truly overheating. With WBH, you won't get the spa-like relaxing feeling of alternating the sauna with some cold showers, but instead, inducing fatigue and moving towards your absolute maximum heat tolerance is the goal.
As an analogy, you could think about the difference between walking and an intense workout. The former is relaxing, the latter is not. And while sauna use can be relaxing, when you're engaging in WBH you'll experience some uncomfortable sensations and feelings!
Also, in studies with WBH the parameters are usually very well controlled.
Now I've got the definition of WBH out of the way, I'll first start by explaining the underlying theory that Dr. Mason works with. Next up, I explain more about the lessons learned from the podcast. Here's the first thing I learned about the theory:
Lesson 1: Depression Can Potentially Be Understood Through The "Pathogen Host Defence Theory Of Depression"
I'm pretty sure you think the "pathogen-host defence theory of depression" sounds pretty complicated (2; 3; 4; 5)!
Nothing could be further from the truth, however:
From an evolutionary perspective, depression is really strange! Let me explain:
Assuming that all species reproduce, if possible, to ensure the survival of a species, depression is really weird. Why? Well, if you were a depressed ancestor you weren't really in the mood to gather food or hunt for it, let alone reproduce.
in such a case, the mystery is thus to explain why depression exists from an evolutionary perspective because it directly counters the goal of reproduction that ensures the survival of the species. And yet, a high number of genetic mutations that favour depression exist. The question then becomes, "why have depressed people reproduced?"
The explanation of the "pathogen host defence theory of depression" begins by stating that inflammation, the human immune response, and depression are all interrelated.
Research shows those concepts are indeed interrelated: some types of depression are linked to higher inflammation (6; 7; 8). Also, in both high inflammation (assuming there is such a monolithic thing) and in a state of depression, conserving energy is a major behaviour.
Therefore, the evolutionary benefit of depression linked with high inflammatory states is that the conservation of energy allows you to better deal with the presence of pathogens.
In certain instances, your ancestors might have lived in a jungle where there's a ton more exposure to pathogens than in clean modern environments. The case can be made that you and I are currently not exposed to pathogens the way our ancestors used to be (9; 10; 11).
Nevertheless, when such pathogens were present in the past, the inflammatory response - mediated by "cytokines" - allowed your immune system to work more optimally. "Cytokines" are signalling substances in your immune system, whereby different parts of your immune system can communicate with each other.
The combination of depression and energy conservation thus allowed some of your ancestors to survive because they were better able to deal with pathogens while others didn't.
But how do you and I use that fact? Here comes the next lesson:
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Lesson 2: Infra Red Saunas For Depression Might Support Health Through Lowering Inflammation In Some People
Let me take a step back first:
In no way are the proponents of the pathogen-host defence theory of depression claiming that all depression is characterised by inflammation. Some types of depression aren't paired with higher inflammatory levels. Increasing inflammation does also not always cause depression.
(The term "inflammation" is an oversimplification too because there's no monolithic entity called "inflammation". Because I want to make Dr. Mason's argument accessible to a broader audience I've simplified the argument on some points.)
Rather, the claims is that some types of depression are paired with high inflammation, and that high inflammation can help some parts of the immune system while lowering the effectiveness of others (12; 13; 14).
But how do you use an infra red sauna for depression?
Simple: a sauna and depression are related because the former can lower inflammation dramatically in some people. If you're a person where high levels of inflammation and depression are linked, then "whole body hyperthermia" - through an infrared sauna - can entail a working therapy works for your depression.
So far my treatment of the "pathogen-host defence theory of depression". Below I've laid out the argument in Dr. Patrick's #67 Podcast, adding in my perspective and scientific references wherever necessary:
Lesson 3: Whole Body Hyperthermia Studies Do Show That Using A Sauna Benefits Depression In Some Individuals
In a classical study of 2016, WBH was compared to a sham treatment to see whether (15). Intervention participants were subsumed into a tent that caused extreme heat, while the control group went into that same tent but the infrared lights were not fully turned on.
So even the control participants got infrared light exposure and psychologically thought they were treated even though they were not. In fact, 71% of control participants actually believed they received the real WBH treatment.
Even after treatment, the sauna was turned off and participants stayed in the sauna for another hour, which further increased their body temperature.
In the study, just as with our Clearlight Saunas, the head didn't get exposed due to the tent only overlapping the shoulders of both the control group and participants.
The study outcome? Just a single WBH session improved their depression score on a clinician-rated questionnaire up to a 6-week period. The WBH group did much better than the control group, implying that reaching higher internal temperatures does have potential benefits.
(Keep in mind that Dr. Mason is not saying that other treatment modalities such as psychological therapy or medication aren't necessary or don't work - she's saying that in some part of the population - but WBH can have very strong effects in some people too!)
One other benefit is that the effects of the treatment came on very quickly, after a week. Let's explore why that link matters:
Lesson 4: Depression And Temperature Dysregulation Can Be Interrelated
Dr. Mason also notes that some common antidepressants - which takes weeks or months to have an effect - have excess sweating as a side-effect. My double-check of the science confirms that claim (16; 17; 18).
Next up, Dr. Mason claims that there's a link between depression and temperature dysregulation. Some of the studies I looked at - while they may overlap with Dr. Mason's citations - show the same (19; 20; 21).
The significance of these findings? The quick effect of WBH together with the slower effect of antidepressants and the links between depression and temperature dysregulation entails that the WBH treatment avenue is very promising to explore!
Dr. Mason remarks that temperature dysregulation also subsides once the depression ends, in some people, which entails an even stronger link. Let's explore how you can use this therapy through a sauna:
Lesson 5: Using A Far Infrared Sauna For Depression Might Be Less Intimidating Than Exercise
A full-spectrum sauna that also emits "near-infrared" might be even better though! Here's why:
During the podcast, Dr. Patrick claims that there's a strong link between exercise and reducing symptoms and the presence of depression. Once more, my dive into the literature confirms that assessment (22; 23; 24). That same literature also demonstrates that there's a "dropoff" in such studies, because some participants don't adhere to consistent exercise regimens - even though they don't necessarily need to be intense to get a benefit!
My reading of the science shows that it's specifically adherence to protocols that are important for good outcomes!
So let me explain how sauna benefits depression symptoms and more: if you're depressed and low-energy, the step to exercise is usually even greater than for a healthy person. For that reason, spending motionless in a sauna - perhaps with some good music, relaxing aromatherapy, and uplifting salt therapy - is not as big a step.
Dr. Patrick also mentions that sauna use mimicks cardiovascular exercise in many ways, such as increased blood flow, higher body temperatures, and a higher heart rate - all of which I agree with and describe in my blog post about infrared sauna advantages.
Dr. Mason and Patrick both agree that saunas are an easier alternative if you've got depression, compared to exercise, and that both have some overlap.
Lesson 6: Home Saunas Can Be Excellent Options As Far Infrared Sauna And Depression Therapy!
Dr. Mason and Dr. Patrick both note that the original sauna in the 2016 landmark study is a $50,000 model that's unaffordable for the average person (15).
I wholeheartedly agree!
The solution? Testing WBH with less expensive sauna models so that consumers can eventually know whether a far infrared (fir) sauna cures depression in them!
Dr. Mason did exactly that and tested several sauna models and their effect on core body temperature.
Remember that if your core body temperature doesn't go up sufficiently, you're more engaging in "spa-like" relaxation sessions instead of WBH. And, without WBH, the effect upon depression by the sauna is weakened!
How do you achieve such a high core body temperature? Follow the golden rule and keep your head out of the sauna! That way, you can heat up without fainting or passing out! For Dr. Mason, only the sauna dome model really worked for this purpose.
Dr. Mason learned that you can stay a long time in the dome models and get the WBH benefits compared to other models. In this study the Clearlight Sauna Dome was used as you can see in the YouTube video.
Lesson 7: Water & Ice As Dr. Mason's Whole-Body Hyperthermia Sauna Session Upgrades
How do you stay in a sauna long enough for maximum health benefits?
Simple: drink enough water when you're thirsty and cool down your head even further by placing ice on it! Just those two adjustments caused participants to be able to stand inside a sauna dome for over an hour!
Also, heating your body for a longer period of time might also matter. Dr. Mason cites research - that I haven't been able to reproduce - stating that WBH sessions have a greater effect on depression if it takes longer for you to work up to the maximum core temperature. The assumption here is that you don't perceive being heated up slowly instead of quickly.
Now let's look at how Dr. Mason will apply this research in her upcoming studies:
Lesson 8: How I Got Inspired By This Podcast: Investigating Detoxification And Seasonal Depression
Before I tell you how I got inspired, let's consider some of Dr. Mason's recent research:
In their podcast, Dr. Mason mentions currently working on two new WBH studies in relation to depression.
During both of these studies, many different biomarkers are measured, such as "BDNF" (related to brain health and regeneration), heat-shock proteins (interrelated with the body's capacity to sense heat), immune-related parameters, body temperature at night outside the sessions, and more. All of these parameters can be related to depression once more as well.
Here's the study setup:
- In the first study, 16 adults with clinical depression use both WBH and "CBT" - or Cognitive Behavioral Therapy. In CBT, thoughts and behaviours are aimed to be influenced so that they better align with reality, almost always intermediate by feelings. Irrational thoughts are corrected so that your behavior and feelings are influenced. The goal is to look at whether WBH makes people feel better, and then be more social and engaging with CBT.
- In the second study, 30 people, half get CBT, the other half get WBH combined with CBT, and then the effects on depression are measured. The goal is to study whether the first works better than the last - CBT has a great track record as a depression treatment.
Also, one key tenet across these two studies is that multiple sessions are used over a longer period of time. The nature of these studies is thus dynamically different than what the original 2016 WBT study used (15). Study outcomes are also measured over a longer than 6-week period.
So how did I get inspired by this setup?
Well, at Clearlight we've been writing a long time about the benefits of infrared saunas - some are less well understood. Let me explain:
- Contrary to popular belief, I certainly think there's ample evidence to suggest that human beings detoxify heavy metals through the skin. Many news sites have tried to debunk that statement in recent years, but I think the evidence that detox happens is very strong. So I'd personally like to see some more research into how concepts such as "fir sauna", "mercury", "depression" intertwine, as well as other metals such as cadmium and lead.
- I'd also love to explore the link between seasonal depression and infrared sauna use. The "Seasonal Affective Disorder" (SAD) type of major depression has a great cyclical component, and now I'd like to know whether the increase in air temperatures and higher exposure to infrared light that people with SAD have outside the winter months helps them. We might even contribute to that dynamic with our seasonal depression light therapy sauna, by adding red light therapy to the full-spectrum infrared light. Light therapy treatments have decent scientific backing for SAD (25; 26).
That's my take on this wonderful podcast episode. Let's now conclude:
Conclusion: Why Infrared Sauna Helps With Depression In Some Individuals?
Hopefully, you've learned that not everyone is the same biologically. Humans have different sleep patterns - exemplified by the existence of evening owls and morning larks - and different ways of responding to toxins or heat.
So, for you infrared saunas might help you feel amazing, while for other people that's not necessarily the case!
Lastly, if you want to learn more about the then read the pathogen-host defence theory work by Dr. Charles Raison and Dr. Andrew Miller. Again, Dr. Charles Raison was also featured on podcast #41 of Found My Fitness with Dr. Rhonda Patrick!