Welcome to a preview of the ninth Ask Me Anything (AMA) episode, part of the Huberman Lab Premium subscription.
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In the full AMA episode, we discuss:
- How Does Infrared Sauna Compare to Traditional Sauna
- Neurological Impact and Best Practices for Journaling for Goals, Habits and Growth
ANDREW HUBERMAN: Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today is an Ask Me Anything episode or AMA. This is part of our premium subscriber channel. Our premium subscriber channel was started in order to provide support for the standard Huberman Lab podcast, which comes out every Monday and is available at zero cost to everybody on all standard feeds, YouTube, Apple, Spotify, and elsewhere.
We also started the premium channel as a way to generate support for exciting research being done at Stanford and elsewhere, research on human beings that leads to important discoveries that assist mental health, physical health, and performance. I'm also pleased to inform you that for every dollar the Huberman Lab Premium channel generates for research studies, the Tiny Foundation has agreed to match that amount. So now we are able to double the total amount of funding given to studies of mental health, physical health, and human performance. So without further ado, let's get to answering your questions.
The first question is about kratom. And the question is what are the short and long-term effects of taking kratom? For those of you that haven't heard of kratom, kratom is a substance that comes from a tree that grows naturally in Indonesia. The tree itself is called Mitragyna speciosa. And it's been known for hundreds of years or more. We don't really know how long, but at least for a couple of hundred years that when people chew the leaves of this tree they experience a mild stimulant effect.
And there's also a process of extraction whereby you can take the leaves and get high concentrations of kratom that nowadays is packaged into various supplements, most often consumed in capsule form, although sometimes it's sold in raw powder form. Here's the key thing to understand about kratom. Indeed, at low dosages, kratom has a mild stimulant effect. However, at higher dosages, it has what's called an analgesic effect, that is, a painkilling effect, and it acts as a sedative. And kratom itself acts as an opioid in the body.
This is what's making kratom a very controversial topic these days, in particular because most people have heard of the so-called opioid crisis. The opioid crisis has been a term coined to largely center around issues that have taken place in the United States, although these issues definitely extend beyond the borders of the United States. But the opioid crisis is essentially the overconsumption and widespread addiction to opioids. Opioids include things like morphine, oxycodone, also called OxyContin, and there are other opioids similar to those compounds, all of which have the general effect of being painkillers and sedatives and in some people, again, some people, eliciting a sense of euphoria, in particular, at low to moderate dosages.
However, people quickly develop a tolerance to those drugs and need to consume more and more of them in order to get the effect that they initially got from a lower dosage. And they are not just highly habit forming, they are highly addictive. And we can distinguish between habit forming and addictive by simply saying that addictive means people will continue to take something or do something despite negative consequences.
There are other relevant definitions of addiction as well. I define addiction more broadly as the progressive narrowing of the things that give you pleasure. And, indeed, when people get addicted to opioids, it is a very bad picture. It often hampers many, many areas of their lives and seriously so.
So the opioid crisis refers to the overprescription of opioid drugs. That's sort of what it's generally taken to mean. But it also includes accessing opioids such as morphine, oxycodone, et cetera through gray market sources, through black market sources, and on, and on. And, of course, the acquisition of the drug is just one piece. It's also the over consumption of those drugs and, of course, the addiction to those drugs, which has proved to be so pernicious.
So what does this have to do with kratom? Kratom is also an opioid, and we'll talk about how it differs in its opioid properties from the drugs I just talked about because it is different from morphine and hydrocodone. But it also has some similar properties as well. But the deal with kratom is that a good number of people out there have managed to wean themselves off opioids such as morphine and hydrocodone through the use of kratom. And that has been used as a justification for keeping kratom on the market and keeping it legal.
However, and this is a very important however, kratom itself has also proved to be not only habit forming but addictive, especially when taken at dosages that exceed that lower dose that just generally creates a bit of stimulant, a little bit of euphoric effect. When people start taking higher dosages of kratom, it is very clear that it does become addictive and itself is very hard to come off of so much so that people experience so-called kratom withdrawal.
Now the reason I mentioned that kratom has been used by a good number of people to wean themselves off of the more potent forms of prescription opioids is that when I solicited for questions about kratom on social media, it was a very binary response. In fact, there was one camp, a very rabid camp, that said kratom is terrible. I took this stuff. I got addicted. It was extremely hard to come off of.
There were additional comments in there such as I know somebody who literally had to go to rehab because of kratom, who developed a bunch of other addictions because of kratom, essentially many, many responses of people who had only bad experiences with kratom, meaning they liked it enough at first that they continued to take it. And it became addictive for them or somebody that they know.
However, there was another camp that was equally vocal, which kept saying, no, if one really adheres to the lower dosages of kratom, kratom itself can be a useful tool for getting off other opioids. And there were even a few bonafide medical professionals, medical doctors, that is, and I happen to know them and their reputations as quite good, who chimed in and sort of reconciled the two camps by saying, indeed, if one can avoid taking kratom at all, you should.
There is no reason to take this thing thinking that it's quote, unquote, "good for you." You would be wise to avoid taking it because there is a high probability if you take it at a given dosage or at a dosage that is going to get your brain and body into a state of euphoria, analgesia, and the sort of classic opioid effect, that it's going to become habit forming or addicting for you. That said, these same medical professionals acknowledged that a fair number of people that they knew managed to get off of the more potent forms of opioids such as morphine, oxycodone, and so forth using kratom.
And they said, well, if it's a choice between being addicted to morphine and hydrocodone versus taking kratom and addicted to those substances and kratom somehow allowed them to taper off of those substances, that they would look more favorably upon kratom if and only if they would also commit to progressively lowering their dose of kratom and eventually coming off of kratom. So the general takeaway from all of that is if you can avoid taking kratom, meaning if you haven't taken it already, don't.
And that reminds me of a very important point, which a guest on the Huberman Lab podcast, Dr. Robert Malenka, who's a MD and PhD-- he's my colleague at Stanford School of Medicine. He's a world expert on the mechanisms underlying addiction, and dopamine, and drug reinforcement, among many other things. What he said on the podcast is absolutely true, which is that it is impossible to get addicted to a substance that you've never consumed.
That might seem obvious, but think about that one again. It is impossible to get addicted to a substance that you've never consumed. So I think the safest statement to make is if you have not tried kratom, you would be wise to avoid it because you stand a chance to become addicted to it.
If, however, you are somebody that's addicted to other forms of opioids, you absolutely should talk to your physician about that and how to get off of those opioids. But there is evidence that some people have used kratom to successfully wean themselves off the more potent forms of opioids that I talked about, namely morphine, and hydrocodone, as well as a few others.
Now if you're somebody who already takes kratom, you need to be very thoughtful about the dosage that you take. And you also need to be thoughtful about the fact that people differ dramatically in their response to opioids. This is oh so important. And people do not talk about this enough. We hear, for instance, that, oh, if people are taking anywhere from 1 to 5 grams, maybe 1 to 6 grams of kratom per day, that's keeping it in the dosage range for which people don't generally tend to get addicted. You'll hear things like that.
And by the way, when I say 1 to 5 or 1 to 6 grams per day, I'm not talking about the individual compounds that are present in kratom. There are a couple of different plant alkaloids I'll talk about in a moment that are present in kratom. And these have different effects on the opioid system.
So nowadays some of the companies that sell kratom-- and by the way, this is sold over the counter as a supplement. It does not require a prescription to purchase at least at this point in time in the United States. Some of these products will have a higher concentration of one or the other alkaloids within them such that you can't really compare 1 gram of one brand of kratom to 1 gram of another brand of kratom because they can have wildly different levels of these different alkaloids.
And these different alkaloids have wildly different impact on different aspects of your brain and body biology, in particular, how much they tend to impact the so-called endogenous opioid system. So when we talk about dosages, we have to keep this in the back of our mind. And we have to keep in the back of our mind that there does seem to be a subgroup of people-- we don't know how big this subgroup of people is, but we know it's not everyone. But it's somewhere between 10% and 40% of people seem to respond to opioids in a particularly potent way. They really like them.
And perhaps not surprisingly, people outside of that category don't tend to like opioids. I can certainly say that I am somebody who when I've been prescribed things like Vicodin or any other opioid post-surgery for pain, I hate taking those drugs. I absolutely hate it. I'd rather deal with the pain. They make me nauseous. They make me feel terrible.
That said, I know people who love opioids. It's like a natural fit for their chemistry in the sense that it tends to evoke more euphoria. They just immediately like the feeling. Some of you may remember the episode of the Huberman Lab podcast that I did about alcohol. And there, too, I discussed the fact that about 8% to 10% of people who consume alcohol get an increased dopamine response to alcohol that's not observed in other people. And that particular subgroup of people is very, very at risk for developing alcohol use disorder, sometimes called alcoholism, because they can drink in a way and they experience a high from drinking in a way that other people simply do not experience.
Now like everybody else if they consume too much alcohol, they get drunk. So it's not about the drunk effect. It's about the dopamine and other sorts of chemicals that are released in those people in response to alcohol that other people just don't seem to experience at the same level of potency.
So, again, with things like kratom and the other opioids, there's a category of people-- and it's a much larger category of people, again, 10% to 40%. We don't know exactly how many because the studies are not really completed. And there aren't enough of those studies yet unfortunately. But when those people take an opioid, wow, oh wow, do they like it. And those people, in particular, are very much at risk for developing an addiction to opioids.
And so those people, especially should never ever go near kratom if they haven't or if they are already taking kratom, these are the people that are constantly ratcheting up their dose. These are the people that tell you, no, I'm not addicted. But if you were to say, hey, all right, well, then let's do an experiment where you don't take kratom for a week. Those are going to be the people that are suddenly going to get anxious about the mere idea of that. I've also talked about this in reference to cannabis when I did an episode about cannabis.
Again, I'm not putting a blanket statement out there about cannabis as being good or bad on that episode. I talked about the fact that cannabis does indeed have various therapeutic uses. But that there are a good number of people who rely on cannabis for anxiety control and other ways of modulating their brain chemistry and bodily chemistry such that if you were to say, hey, are you addicted to cannabis, they'd say, no, I don't have to smoke cannabis, I don't have to take my edibles.
But if you were to push them a little bit and say, all right, well, then let's do an experiment where you don't consume any cannabis in any form for 10 days, they don't like the idea of that experiment at all so much so that were they to run that experiment, they would experience a lot of the withdrawal symptoms associated with addiction. So I can't in good faith say that kratom is safe for everybody because it is simply not.
Now is it safer than the other opioids? And if so, why? Well, in order to address that, let's take a short glance at the pharmacology of kratom and how it works in terms of its neurochemistry in the body. And I'm going to keep this pretty brief because in the future I'm going to do an extended episode all about opioids, and I will include kratom in that conversation.
But just to back up a little bit and discuss what opioids are, opioids are compounds that can activate the so-called endogenous opioid system. All of us have within our brain and body the capacity to release our own opioids. That's right. You have opioids within your body. They are released from neurons. And they bind to so-called opioid receptors. Perhaps some of you have heard of the so-called runner's high. The runner's high is a euphoric state. It's a fairly mild euphoric state in most cases.
But it's a euphoric state induced by long duration effort, a.k.a. the runner's high. The runner's high is just a phrase used to explain that when we engage in long-duration, repetitive action effort, the body starts releasing these endogenous opioids. They bind to receptors, and they trigger things like analgesia, relief from pain. They trigger mild euphoria. They tend to change our perception of the outside world, make things look more beautiful, shiny. They give things a little bit of a sheen.
What I just described is a mild version of what people experience when they take something like morphine. When people take morphine, there's a more of a sedative effect. There's more of a euphoric effect. And there's more of a dreamlike effect. And, again, it will depend on dosage.
Kratom, and morphine, and hydrocodone all have the property of acting like the endogenous opioids but at much higher potency. When you bring them into your system, they cross the blood-brain barrier, so they go into the brain. And they bind to a number of different opioid receptors. There's the mu opioid receptor. By the way, these names all follow Greek alphabet letters. So the mu opioid receptor, the kappa opioid receptor. There are a bunch of different ones.
Kratom binds preferentially to the mu opioid receptor and somewhat to the kappa opioid receptor. There's a big misconception out there. A lot of people, especially people who are proponents of kratom, will say, no, morphine and hydrocodone bind the mu opioid receptor, whereas kratom binds the kappa opioid receptor. So it's a different compound, very, very different. Not true. Not true. Kratom, morphine, hydrocodone all bind to the mu opioid receptor. And that's what's largely responsible for its opioid-like effects, especially when you get the dosage up to a level where you start getting the mild sedation, the analgesia, the pain relief.
And keep in mind, a lot of people are taking kratom because they want pain relief. And when that mu opioid receptor system is activated, it indirectly activates a lot of the reinforcement circuitry in the brain that relates to dopamine and serotonin. This is another area that we'll go into in more depth in the future. But there's been a lot of controversy people saying, oh, kratom doesn't trigger the dopamine system. Therefore, it's not addictive.
But that is simply not true. It indirectly activates the reinforcement circuitry that includes both dopamine and serotonin. But its primary effect is to hit this mu opioid receptor system that exists in a bunch of places in the brain but mainly in the brain stem in a structure called the periaqueductal gray nucleus, which then provides pain relief. It triggers a number of different shifts in cognition. It's what creates that mild euphoria, et cetera, et cetera.
Now how can we be so confident that kratom is acting so similarly to hydrocodone and to morphine albeit with lower potency? And the reason is if you give people a drug that blocks the mu opioid receptor prior to them taking kratom, they don't experience any of the classic effects of taking kratom. No euphoria, no analgesia, no sedation, even at the low dosages, no mild stimulant effect.
So we really have to look at kratom as an opioid. That's just the honest truth. And if you're somebody who doesn't like this message because you like kratom, I'm not telling you that you don't like kratom. I'm telling you, you likely like kratom because it's an opioid.
So, again, if you go online and you start asking questions about kratom, again, you're going to see these two camps. You're going to see the kratom is terrible, it's addictive it's everything bad camp. And then you're going to see the other camp out there, very vocal as well, talking about how kratom helped them avoid other things that are worse. And this is an argument that, frankly, I don't think we want to lean on, the idea that substance A is not as bad as substance B and that making substance a unavailable is just going to send everyone running for substance B.
That's a weak argument frankly. I heard this argument around cannabis. And by the way, I'm I think pretty balanced about cannabis if you listen to the episode I did on cannabis. I think you'll agree that I believe that cannabis has its therapeutic applications. I also believe that young people, especially young males with a predisposition to psychosis, should not be taking high concentration THC cannabis because the data tell us they are already at risk of psychosis. And they are at a much greater risk of psychosis if they do.
So I think I'm pretty balanced about the story on cannabis. But I often hear the argument, oh, cannabis isn't as bad as alcohol, and, therefore, cannabis is good. That's simply not rational.
What we should be saying is whether or not it's cannabis, or alcohol, or kratom, or any substance for that matter, what are the potential benefits? What are the potential risks? And, again, this is far too much than we can go into in this AMA. And we we'll go into in a future full-length episode of the Huberman Lab podcast. But the other thing to really keep in mind is the lack of regulation over kratom supplements.
Now as many of you know, I am a fan of many, not all, but many supplements in certain conditions. I always say behavior is first, then nutrition, then, if and only if it's needed, rely on supplementation. But supplementation is a big category. But when we're talking about supplements that are opioid compounds, I start to get nervous because of the high abuse potential and the high addiction potential of opioids. And kratom is included in that category.
A couple of other key notes about kratom. While death directly from kratom is fairly rare, it has happened. Now hydrocodone and morphine suppress respiration, actually suppress breathing by way of a mechanism that if you're a listener of the Huberman Lab podcast, you know about, which is the so-called physiological sigh. Many of you have heard me talk about the physiological sigh is something that you do voluntarily, the double inhale through the nose and then a long exhale in order to rapidly reduce your level of stress.
As far as we know, that's the fastest way to deliberately lower your level of stress. But the physiological sigh was discovered in the 1930s as a spontaneous pattern of breathing that occurs involuntarily in sleep in order to reinflate the lungs and offload carbon dioxide and bring oxygen back into the system on the subsequent breath.
When I interviewed Dr. Jack Feldman, who is a professor at University of California, Los Angeles, and really the pioneer of the modern neuroscience understanding of respiration, he talked about some studies in his laboratory that were exploring why people die when taking opioids. This is a major issue associated with the opioid crisis.
And what he mentioned was that the opioids bind to particular receptors in the brain stem locations that generate physiological sighs. So opioids when taken as drugs suppress physiological sign and do so during sleep. And lack of adequate respiration, meaning people stop breathing during sleep, is one of the primary reasons why people die when they take opioids.
Now kratom is not known to suppress respiration when taken at low to moderate dosages. But when combined with any other opioids and certainly when combined with alcohol, it can suppress respiration. And while the data on this are fairly scant, there is some evidence that kratom-induced death is caused by suppression of the respiration system.
So, again, death due to taking kratom at the dosages that are recommended on most commercial packaging is fairly rare, although it has happened. It's unclear if it happened because it was taken in combination with other compounds. That seems likely.
But we can't forget that a lot of people are taking kratom at much higher dosages and, in fact, progressively higher and higher dosages from these over-the-counter sources. And with increased dosage, there is, yes, an increased risk of respiratory failure. So, again, all of this points to the fact that kratom is simply not a benign substance.
So if we're going to be very honest, the addictive potential of kratom is real. It is exacerbated for some people compared to others. But it is real. It's very similarities to other more potent forms of opioids are what make it attractive for some people who are trying to come off those more potent form of opioids.
But the goal, of course, is to completely come off all opioids. And kratom itself can be a bit of a trap. It can be a trap in the sense that people who have never taken other opioids can become addicted to kratom itself. That is absolutely clear that can happen. It has happened in a great number of people. It's also clear that kratom can potentially be a trap.
Notice I said potentially. Because if people are trying to come off other more potent forms of opioids and then they use kratom to do that and then they're ratcheting up their dosage of kratom such that they're now matching the endogenous response to kratom in a way that doesn't really distinguish from the effects that they were getting from morphine and hydrocodone, well, then they're just using a different form of morphine and hydrocodone. And I'm sure that some of you are out there saying that is ridiculous. You cannot compare the effects of kratom to the effects of hydrocodone. But the potency is about one sixth of hydrocodone.
And there are people out there who are just increasing and increasing both the dosage and modifying the type of kratom that they're taking so that they're getting the kratom that has a particularly high concentration of one of the alkaloids that hits that mu opioid receptor hardest. And in doing so, sure, they're not getting the pure hydrocodone effect, but they're getting really close. So my advice would be, if you haven't touched kratom, don't touch it at all ever. If you are taking kratom, you need to take note of what we just discussed.
So the next question I received that got a lot of upvotes was about infrared sauna. And the question was how does infrared sauna compare to traditional sauna? This is a great question, and it's one that I get a lot. First of all, I did an entire episode of the Huberman Lab podcast all about deliberate heat exposure. So the use of sauna as well as hot baths in order to stimulate certain biological and psychological effects.
And just to review a couple of what those effects, there are some well-known cardiovascular benefits of doing regular sauna. It gets your heart rate elevated. It has positive effects on the small capillary system and the venous systems of the body. There's also evidence that you release certain endogenous opioids.
You now know what those are, in particular, one called dynorphin which, as some of you know, is not an endogenous opioid that makes you feel good. It actually binds to a receptor system that makes you feel kind of lousy. But once activated, the dynorphin system can up regulate mu opioid receptors allowing the opioid system that operates naturally, again, away from all the drugs and kratom that we were talking about a few minutes ago-- we're talking about the release of endogenous opioids binding to those now elevated numbers of mu opioid receptors and making you feel really good for many, many hours, even days after getting out of the sauna.
So those are just a couple of the positive effects of deliberate heat exposure that have been demonstrated. There are others as well, namely that if you do deliberate heat exposure say one time a week versus four times a week, they have vastly different impact on things like growth hormone. Just to briefly summarize, it does seem that the more frequently that you do sauna, up to four or more times per week, that you get increased benefits with respect to cardiovascular functioning and cerebrovascular functioning. So it seems more frequency of sauna or other forms of deliberate heat exposure is better if you're talking about lowering risk of heart attack, lowering risk of stroke and other forms of cerebral vascular disease.
However, with respect to triggering big increases in growth hormone, the opposite appears true. In this study that was done out of Finland-- and, granted, it's a small study. And it was some years ago. But the data are just, oh, so robust that we have to discuss them.
And I did discuss them in that episode. And I'll just mention here again that when people did four sauna sessions in one day, one day per week, they saw very big increases, literally 16-fold. I know, sounds outrageous. But this was one study. And this was very robust use of sauna, four times in one day. I talk about that protocol in that episode.
We also have a newsletter all about deliberate heat exposure that details that protocol. They saw these huge increases in growth hormone. However, if people did sauna more often than that, they saw still significant yet diminished levels of growth hormone release with each successive sauna session. So this is important to realize. And it relates to a bunch of other things about stressors in the body and infrequent stressors versus frequent stressors and adaptation to heat, et cetera, all of which is covered in that episode on deliberate heat exposure.
Now I should also mention that there were increases in other hormones, including prolactin. So it's not like growth hormone is the only hormone that increases when one does sauna in that four-day session type format. So in any event, if you're curious about the effects of deliberate heat exposure on cerebral vascular function, cardiovascular function, hormones, and so forth, check out that episode that I did. We provided a link to it in the show note captions.
And also take a moment, if you would, to download the newsletter. It's completely zero cost. Download the newsletter on deliberate heat exposure. It's a two or three page PDF. I don't recall exactly how long. And it details the various protocols and some links to the science that are relevant.
But the question at hand now is about infrared versus traditional sauna. So when we're talking about traditional sauna, what we're talking about is either wet or dry sauna. So this could be sort of steam room type sauna or it could be a sauna that feels more like dry sauna. It might have some steam in there, but there's not deliberately a lot of steam pumped into the room.
Traditional sauna, more or less, includes both of those. And it's the sort of experience that if you get into a barrel sauna or you get into a chamber sauna of any kind. And the temperature tends to be somewhere between 175 and 220 degrees Fahrenheit.
Now it could be higher than that. Indeed, my heat tolerance is very high. I've been doing sauna for a lot of years. I do it regularly, at least one day per week and, more typically, two or three days per week. And so I've learned to tolerate much higher temperatures. I do not recommend that you start at the higher temperatures.
I also want to emphasize that if you're pregnant, if you're breastfeeding, if you're a child, if you're concerned at all about any major health issue, you, of course, need to talk to your doctor before doing sauna. But you would be wise to avoid it if you were in any of those previous categories I just mentioned. And, of course, if you're going to get into a sauna and it feels just so uncomfortably hot that you don't want to be in there, you should get out.
Don't ever push yourself to stay in an excessively hot environment under any conditions because the brain can tolerate getting quite cool. The brain can't tolerate getting very hot before you start killing neurons. And once you kill neurons, they do not come back.
So that usually opens up a discussion about, well, how do I know if I'm killing neurons? Well, if you're feeling nauseous, you're feeling panicked, you're feeling any of those not good feelings while you're in the hot sauna and it's not something that you can simply just take a couple of deep breaths and relax into and then feel better, you probably should get out. So err on the side of caution always.
Now that said, the signal to get out of the sauna or any hot environment for that matter comes from the brain. So if you go to a traditional banya, Russian banya, what you'll notice is that people often wrap their heads in a towel or they will wear a wool cap, which might seem counterintuitive. Why would they put a wool cap on in a hot sauna? That's actually allowing people to stay in longer because it insulates your head, your brain against the heat.
So putting a towel on your head while you're in the sauna is a good way to be able to tolerate that heat without your brain heating up too much. But, of course, you don't want to be in any environment that's so hot that you cook your skin in any way, of course. The point being that traditional sauna typically involves heat levels of 176 to about 220 degrees Fahrenheit. Typically 190 or 200 is where most people's threshold is, and they can't be in there for more than 15 to 30 minutes without feeling like they really need to get out.
Remember to always hydrate. Remember that hydration with electrolytes is going to be especially effective. This does not mean you have to purchase anything. You could even just some water with a little bit of sea salt, sodium in there. But you could also use commercial electrolyte powder if you want to do that. But you certainly want to hydrate. You want to hydrate before, ideally during and after being in the sauna.
Now the question is about infrared saunas because this person clearly knows that when you get into an infrared sauna, rarely is that infrared sauna much hotter than 175 degrees Fahrenheit. And oftentimes it's down in the 150s or maybe up to 180, but rarely into the temperature ranges for which the vast majority of the peer-reviewed scientific data on sauna have been published. And this is the key point here. Most of the quality data from peer-reviewed articles that have been published about the effects of sauna, whatever those may be, hormonal, cardiovascular, cerebrovascular, were done in studies where the sauna that was used was a traditional sauna, might be a steam sauna, might be dry sauna, but traditional type sauna.
And the temperature tended to be somewhere between 175 and 220 and, most typically, between 190 and 200 or 190 and 210. So it's very hard to say whether or not infrared sauna has any benefits that are unique and separate from traditional sauna benefits.
There's reason to think that there could be certain benefits of the infrared light itself. For instance, I did an entire episode of the Huberman Lab podcast all about light and health where I talked about the fact that far red light and red light-- so these are going to be wavelengths, for you aficionados, that are out in the 660 to 720 nanometer range, so red appearing lights as well as far red, so infrared, that we can't see-- the pit vipers can, but we can't-- have been shown to do things that are interesting and positive, such as accelerate wound healing, in particular, to the skin, to create certain endocrine hormonal effects that seem to be beneficial-- they're pretty mild effects there-- treatment of acne.
The data there are actually quite interesting and fairly strong. And the experiments are pretty cool too. They have people who unfortunately are suffering from acne. And they participate in these experiments where they expose half of the face to red light and infrared light. And they experience some diminished acne on the side that was treated versus the other side. It's always nice when you have this so-called within person control.
Now keep in mind that the red light could have both local effects on the skin as well as triggering more systemic effects through the release of hormones, anti-inflammatory molecules, et cetera. So you wouldn't even necessarily expect the effect to be restricted to just one side of the face. But in some of those experiments, that's exactly what they observed.
There's also some evidence that red light presented to the eyes, especially in the morning and for people 40 years old or older, can help suppress some of the effects of age-related vision decline, in particular, in people who are at risk for age-related macular degeneration. But those are ongoing studies. It's early days.
Nonetheless, I know a number of people who are exposing themselves to red light in the morning. Keep in mind that if you expose yourself to red light in an infrared sauna or a red light outside of the sauna, you never want to stand so close to it that it's bright and to the level where you have to strain to keep your eyes open to look at it. Stand back to a point where you can comfortably keep your eyes open. Any closer where you feel like you want to close your eyes, that's a natural system of protecting your eyes against damage.
This is a question I get a lot. Do I wear those little glasses, the glasses that completely occlude the light entry to the eyes? And the answer is actually really simple. Don't look at any light, sunlight, blue light, red light, fluorescent light, any light that's so bright that it's painful to look at.
Never force yourself to look at a light that's so bright that it's painful to look at because that pain is a sign that you are potentially doing damage to your retinas. And as of now, science and medicine cannot satisfactorily repair damaged retinas. So you lose those neurons, you're losing vision. You lose that vision, it ain't coming back. So be careful.
Now what about infrared sauna per se, meaning is there any benefit of being under a red light while in a sauna, especially when those saunas tend to be a bit on the cooler side, not 190 to 200 degrees or even 180 degrees? But they tend to be in the 155 to 165 or 175 Fahrenheit range. And the short answer is there are very few data on this. In other words, yes, red light could be having positive effects on your skin, your hormone system, et cetera.
And if it's on while you're in the sauna, I don't see a problem with that. However, I am not aware of any strong data that describe a synergistic effect of the relatively low amounts of heat that are typically present in infrared sauna plus the red light that provides some sort of increased benefit compared to doing the red light separately from what would be a more effective form of sauna, traditional sauna, at temperatures in the 175 to say 220 Fahrenheit range.
Now I'm also unclear as to why they don't put red lights into traditional saunas. I know some people do that at home. That seems like a simple solution, kill two birds with one stone. But there, too, I have no knowledge of any data that suggests there's a synergistic effect of red light and heat together.
Now a lot of spas like to push the red light sauna as an attractive reason why you should go there. And, again, I'm not saying red light is bad. I did an entire episode on light and health and a good fraction of that episode was focused on how red light and infrared light can be very useful for different aspects of biology, both for brain, and for body, and for skin, et cetera. But I'm not aware of anything that's particularly effective about infrared sauna per se.
And I am aware of a lot of data that, again, was covered in that episode about deliberate heat exposure that points to the fact that when traditional sauna is done at the appropriate frequency, appropriate duration, again, all things that were covered in that episode and the associated zero-cost newsletter, well, that is very beneficial. So I get this question about infrared saunas a lot. And, unfortunately, the short answer is there really isn't anything particularly exciting about infrared sauna that warrants either its purchase above a traditional sauna.
In fact, I'll just say it outright. If you're thinking about purchasing an infrared sauna that doesn't get very hot versus a traditional sauna that gets really hot, I would strongly encourage you to go the direction of the traditional sauna because the benefits there are far better documented. That said, I think there are still benefits to red light exposure. But they needn't be done in the sauna. And there's no evidence, as far as I know, that red light and far red light exposure in the sauna is any better than red light and far red light exposure outside of the sauna.
Now is there any harm to doing red light in the sauna? And the answer to that is I don't think so, meaning I'm not aware of any. And to be quite frank, I think a lot of reason why spas give people the red light exposure in the not so hot sauna is because the red light feels esoteric.
I'm sort of chuckling here. But also people like how they look under the red light. When people go under the red light, it tends to alter their perception of their skin, making it look smoother. While they're under the red light, it's not actually making their skin smoother, by the way. It's giving the perception that the skin is smoother. Blemishes are harder to see, et cetera.
So it feels kind of-- I don't want to say new agey. But it feels sort of techie. It feels special. It feels different. And this is something to keep in mind. A lot of technologies nowadays that are aimed at promoting health or promoting wellness in some way while they could have some benefit, a lot of times they're emphasizing different colored lights or they're emphasizing a kind of esoteric experience, a mask that puts a lot of light. It looks kind of space age, new age, or futuristic in a way that makes people feel like, wow, something really big must be happening.
And, indeed, sometimes there are data to suggest that those products, those treatments can change skin, can change eyes, can change any number of things that are positive. But more often than not, the stuff that I see out there promoting red light, in particular, red light sauna, it doesn't impress me very much. But traditional sauna and the established benefits of traditional sauna are quite compelling.
Now perhaps you've heard the claim that the specific mode of heating in an infrared sauna differs from that of traditional sauna in a way that is especially beneficial for your mitochondria. I've looked at that literature. And the best way to describe my impression of that literature would be it's interesting, but it's not yet compelling enough for at least me to motivate and go buy an infrared sauna or to go to a spa that would allow me to regularly use infrared sauna.
Now there's an easy way to marry what I believe are the two best benefits of infrared and red light with traditional sauna. And that's simply to either do them separately. So there's no reason to think that you have to do the red light and far red light exposure to your skin or whatever part of your body you're trying to augment in the sauna. But there's no reason to think that you couldn't provided the device that you're using can tolerate the heat in the traditional sauna.
In saying this, I also should mention that-- I should also say that in fairness, I know there are a good number of studies happening right now exploring the effects of red light and far red light on mitochondrial health. And I believe those studies are happening because there's enough pilot data, there's enough of a suggestion that there is going to be something interesting and perhaps even positively significant there to motivate those studies. It's just too early to tell right now. As I learn more about the outcomes of those studies, I promise to get back to you with those results.
There's also the idea that somehow when you're heating yourself with infrared light that you're heating yourself from the inside not the outside. That's not really true. What's actually happening is that different wavelengths of light can penetrate to different depths into different material, including your skin. And red light, which is of the longer wavelengths within our visible spectrum, as well as infrared light, which is even longer wavelengths outside our visible spectrum-- other animals can see it, we can't-- can pass through the skin and actually access some of the tissue that lies deep to the skin, including some of the vasculature.
And so there's been a lot put forward about the idea that in infrared sauna you're actually heating yourself from the inside out. And in traditional sauna, it's from the outside in. But in reality, that's not really a fair way to describe the difference between the infrared sauna and traditional sauna. So rather than get into the physics of how red light could potentially heat us from the inside versus traditional sauna, which heats us from the outside-- but then, of course, our body responds to that by generating both the attempt to cool itself and heat from the inside. Rather than get into all of that and try and separate into different little sand piles that are all going to run together, I'm going to stand by my statement that if you want the benefits of sauna, I recommend traditional sauna.
If you want the effects of red light and infrared light, get a red light or infrared light device. Many of those are very useful. I, in fact, use one for other purposes. And use that either outside of the sauna or if it can tolerate the heat within the sauna, inside the sauna.
The next question is about journaling. And I confess I love this question not just because I'm an avid journaler and have been since my senior year of high school, but because there are incredible studies about journaling and its benefits. Now the specific question that I was asked is can you discuss how journaling can impact us from a neurological level and how to apply it for goals, habits, growth? And what frequency of journaling is best, what times of day, how many times per week, handwriting versus typing versus a computer versus phone?
So about a dozen or more questions inside of this one very important question. And I will answer all of those questions in an episode of the Huberman Lab podcast all about journaling. But for right now, I want to talk about the scientific data on journaling as it relates to moving through hard experiences as well as achieving new levels of life progression. That's sort of the general language used in the psychology and sociology literature around journaling.
The other questions that this person asked about journaling are equally valid, goals, et cetera. But journaling is such a big topic because journaling itself reflects all sorts of things related to externalization of our own thoughts, and feelings, and reflections. For instance, there's an entire literature about how when we read back to ourselves what we've journaled, how that shapes our understanding of our own narrative and sense of self. I promise to parse all of that with a lot of actionable tools in a future full-length episode of the Huberman Lab podcast.
However, for now, I'm excited to share with you what I think are some of the most interesting data in all of psychology, truly. This is the work of James Pennebaker. James Pennebaker is now at the University of Texas Austin. Prior to that, he was at Southern Methodist University.
And he was one of the first academic researchers to really start looking at journaling and its benefits in a structured way, asking for instance how often do people need to journal in order to get through something hard in a way that's not quite as hard? What about people suffering from trauma? Can journaling help there? How often do they need to write? And in what form? Do they need to read what they write to other people, et cetera?
And Pennebaker has published a large number of really interesting papers on this topic. The most sort of classic one was one published in 1997. It's actually a little bit hard to find online unfortunately. But it can be located. And I managed to get a copy of it. And I'll provide a link to this really beautiful paper in the show note captions.
The title of the paper is "Writing About Emotional Experience as a Therapeutic Process." This paper was published by the American Psychological Society in 1997. And it pulls together a number of different observations that Pennebaker had made in earlier studies.
And it set the stage for a lot of what came afterwards, including some studies showing how journaling even for just 10 to 15 minutes per day can help people move through and really come to understand childhood traumas, really awful traumas, sexual traumas, wartime traumas, as well as more mild traumas and really help people get to a sense of pervasive relief. So this paper details what is essentially called therapeutic journaling. So I'm going to restrict my answer right now to what's called therapeutic journaling.
Therapeutic journaling is done in a fairly specific way that's different than just sitting down for a few minutes each day and just jotting down your thoughts or kind of doing a mind dump of whatever comes to mind. Therapeutic journaling is quote, "an internal process of using written word to express, and this is important, the full range of emotions, reactions, and perceptions we have related to a difficult, upsetting, or traumatic life event or events. So therapeutic journaling is really about getting the full intensity of emotions out onto paper.
Now Pennebaker has experimented with this method, again, in different populations, young people, older people, veterans, people having suffered from a great number of different things, including people who are not aware that they have trauma. But what it involves is asking people to think about a particularly emotionally difficult circumstance. It could be something from the past, the present, or something that you're anticipating in the future and encouraging them to write about that in a completely unstructured way. That's right, unstructured way for about 15 to 20 minutes, although as short as 10 minutes can work as well.
The key thing here is that this form of therapeutic journaling is done with the expectation that no one except you will ever see what's written. This is really important. A lot of people start to self-edit while they're writing. Pennebaker suggests not correcting grammar, not correcting anything about what you're writing, but to simply get the information out.
Now this can be done, according to Pennebaker, by pen or pencil, so a traditional writing device. It can also be done typing. Get this, for people that are especially wary of thinking about and especially writing about really hard experiences, Pennebaker has done experiments where he's had people simply pretend to write out the difficult experience and their feelings around it using their finger as a pen or an invisible pen or writing device and seeing the same benefits. Wild, right? That's why I'm chuckling, the same benefits as when people actually write this out on paper, which already tells you the answer to the next common question, which is do people need to reread what they've written?
Well, obviously, if they're simply pretending to write something out and not writing it out and they're still seeing the same benefits, then the answer to that is going to be no. You don't need to go back and read what you wrote. And I think this is one of the key elements of therapeutic writing because a lot of people when they sit down to journal are thinking somebody's going to see this or somebody's going to read this at some point. And I want it to sound coherent or I want to be able to fully express the magnitude of these feelings or the confusion. Maybe they're not good at expressing their feelings on paper.
But the point is that Pennebaker tapped into something essential, which is that when people have hard events in their life, things that are uncomfortable for them and that create pervasive emotional stirring of the negative sort, they need to externalize it in some way. And this therapeutic writing has been shown to benefit a huge number of different populations, as I mentioned. And it has been shown to be very potent. It's a really good form of self-directed therapy.
Now, of course, it works best when done in parallel to traditional forms of therapy. It is not a replacement for traditional forms of therapy, although, frankly, a lot of people can't afford or access traditional forms of therapy. So this is another reason why I'm a big fan of this therapeutic writing a la Pennebaker. It's also clear that when people combine therapeutic writing with the other forms of treatment-- of course, some people do need prescription drug treatment, some people need talk therapy X number of times per week or per month-- that it's going to benefit them even more.
Now a couple of key things about the therapeutic writing that perhaps I haven't mentioned. You'll want to ask yourself at the beginning of each session what is the writing topic? And you should pick just one topic for that day. Really focus your energy and try and tap into the emotions around that topic. So the writing topic has to be defined. You can write about that topic every single day if you like or you can write about different topics on different days, but one topic per day.
In terms of the length or frequency, what seems to work best is to write for about 15 to 20 minutes each day for at least four consecutive days before taking a break. But you can take breaks. And that's kind of a nice feature. Any time we hear about some protocol or something useful, we think that if we're going to do it, we have to do it every single day.
And, of course, I encourage people to get sunlight every day, exercise every day, eat well every single day, sleep well every single night, get social connection as often as you can tolerate if you're an introvert or an extrovert. But we don't always succeed in doing all those things every 24 hours. Let's be honest. But we ought to try.
But when it comes to therapeutic journaling, we should strive for at least four days in a row. But then it's OK to take a few days off or more and then return to it. So that's a nice feature. And, again, that's supported by the data on therapeutic journaling.
I mentioned this already, but a key feature is to write only for yourself. You are writing for yourself and no one else. I'm paraphrasing here. After you complete the expressive writing exercise, you are completely free to destroy or hide what you've written or you could use the non-writing writing method of an invisible pen if you prefer, if you're really concerned about something being found.
What to avoid. Pennebaker says if you feel that you cannot write about a particular event because it's too upsetting, don't write about it. Write about other events or situations that you can handle now.
Now another key feature, and I find this to be particularly interesting, is that one of the things that Pennebaker found to be especially effective in allowing people to move through the burdening emotions associated with negative events is to have people think laterally, so to write about a particular incident and think about the emotions, but that anything that comes up in an almost dream-like way-- oh, that reminds you of something, I don't know, the color of your door when you were a kid or a friend that said something, something that's seemingly unrelated-- feel perfectly free to just put that in the margins, maybe come back to it later. Maybe that's the pickup point for the next day's writing session.
What Pennebaker was essentially encouraging here was a lot of what traditional therapy was about, which is allowing people to sort of free associate, but when people hear free association, almost always they default to this picture of the Freudian couch and the free association, talking about dreams, dream analysis, things that are often tacked to let's just say the less favorable view of Freudian psychoanalysis. But that's not what Pennebaker is talking about.
What Pennebaker is talking about is removing the filters of traditional grammar, removing the filters of, oh, somebody's going to see this. It needs to be perfect or it needs to be squared away and any kind of sense of grammar or handwriting. I'm somebody, by the way, who I'll just confess right now for the first time publicly or ever that I have a tendency to write in all capitals. But I can't do that very quickly.
So I'll often revert to cursive and then back to lowercase print when I journal. And when I look at what I'm writing, I often think, oh my goodness, this just looks like chicken scratch. It actually has a rhyme and reason for me. I tend to put certain things in capital letters, block face print, certain things in script, and certain things in lowercase non-cursive depending on what I'm trying to emphasize.
But that's something that I've developed for myself. But I've always had a little bit of embarrassment about that frankly because it makes it look as if my writing is completely chaotic when, in fact, it has a certain internal order that only I understand. But the point being that when you do this sort of journaling, let yourself write in any way that's efficient. Use pictures if you want. Again, this is for you.
Now the good news is the results that you can expect from this form of therapeutic journaling are quite robust in the positive direction. Pennebaker talks about the fact-- and, again, here I'm paraphrasing-- that it's common for people to feel somewhat saddened or depressed after writing about these saddening depressive and challenging episodes, especially on the first day or so that they do that, so keep in mind. But while recognizing that's completely normal as well as if it doesn't happen, completely normal-- it doesn't mean you're not doing it correctly if you don't get depressed about it. If you feel relief right off the bat, great.
But typically that feeling lasts just a few minutes or hours and that the overall positive benefits, both in the short and long term far exceed what people experience when they don't journal. Because, of course, in the stronger of the studies by Pennebaker and others, they, of course, use control groups where they have them do a different type of writing exercise. And they look at the shifts in the psychological scales that measure things like depression, sleep, autonomic function. Indeed, this process of therapeutic journaling has been shown to lower blood pressure, has been shown to improve sleep, has been shown to improve mood and significantly so.
Again, the effects do not exceed traditional talk therapy. But they are on par with some forms of talk therapy. And, again, when combined with talk therapy, meaning done separately from talk therapy-- you don't necessarily have to talk about what you wrote. Keep that in mind. This is something for you done separately. The effects are not as big as they would be if you combined talk therapy and journaling. But they are real. They are there. They are statistically significant effects.
So I highly recommend trying therapeutic journaling a la Pennebaker. And for those of you that are therapists, perhaps you're already doing this with your clients or you'd like to explore doing this with your clients. So I strongly encourage everybody, yes, everybody, even for those of you that don't think that you have trauma, to explore therapeutic journaling because, again, the effects have been demonstrated in those that have trauma, as well as for anybody, even people who report having no trauma.
And this process of therapeutic journaling isn't about dredging things up or going in looking for problems where they don't exist. It's really about allowing you to tap into your own unique way of thinking about and externalizing your negative emotional experiences in a way that at least what the data tell us can be extremely beneficial to allow us to get relief from those negative feelings.
Now for those of you that aren't walking around with this kind of itch in the back of your head about this traumatic event or series of traumatic events, you think, well, why would I want to dredge up negative stuff? It also seems that for people that do therapeutic journaling, again, just four days in a row-- maybe drop it at that point if it's not for you, but I do recommend giving it four days in a row at least. Maybe you do it every day thereafter. Maybe you do it every once in a while for four days. It's up to you.
It's clear that it can benefit people who have experiences that they need to externalize and work through. It's also clear that it can make people who don't feel they have those experiences nested within them feel better overall. And that statement relates to data both on physiology, so things like lowered blood pressure, lower resting heart rate, improved sleep, improved mood, as well as psychological metrics such as positive outlook on life, improved social relationships, et cetera.
So this therapeutic journaling stuff is real. It's potent. It's backed by science. And I must say bless Pennebaker and colleagues for doing this important work because it sets the stage for what is a much larger landscape of options to use for journaling in order to achieve the sorts of things that we're also asked about in the question that was raised, things like how to define and re-establish your connections to goals on a daily basis, how to work through not just challenges but how to identify particular goals that are going to be particularly relevant for you, how to adjust identity, and, of course, how to use those journal materials, because here we're talking about discarding or not reading journal materials again, but how to use those journal materials in order to more quickly and more effectively reach goals. So that will be the topic of a full-length episode of the Huberman Lab podcast. Meanwhile, get journaling.
I'd like to take this time to thank you for joining me for this Ask Me Anything episode. And I'd like to thank you for being a premium subscriber to the Huberman Lab podcast. I'd like to remind you that if I haven't answered your question already that I will be doing these Ask Me Anythings every month. I will continue to sift through the questions that are on the premium website. And I would encourage you to put additional questions there and to upvote questions that you'd like to see the answers to.
If any of the questions that I responded to today you didn't feel were thoroughly answered enough, then please add a new question there and point that out. I will read all the questions that are there. And I will strive to answer them as thoroughly, concisely, and clearly as possible. Again, you can put those at hubermanlab.com/premium. And as always, thank you for your interest in science.
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