Summary
Shawn Stevenson interviews Dr. Susanna Soberg, one of the world's leading researchers on cold immersion therapy and brown adipose tissue. The conversation covers the science of brown fat, how it differs from white fat, and why cold exposure is one of the most effective ways to activate it for metabolic benefits. Dr. Soberg explains the mechanisms behind cold shock proteins, their role in cellular repair, and how they differ from heat shock proteins. The episode dives deep into the practical applications of cold therapy, including its effects on insulin sensitivity, inflammation reduction, immune system modulation, and mental health. Dr. Soberg shares her research findings on how regular cold immersion lowers blood pressure, improves stress resilience, and activates both the sympathetic and parasympathetic nervous systems. She explains the concept of hormetic stress and how short-term cold exposure builds long-term resilience. Key practical takeaways include the recommendation to always end contrast therapy sessions on cold rather than hot, to use nasal breathing during cold immersion to shift from sympathetic to parasympathetic activation, and that the body adapts quickly to cold exposure. Dr. Soberg also discusses the important role of dopamine released during cold exposure, which mirrors the effects of exercise on the brain's reward system.
Key Points
- Brown adipose tissue burns calories rather than storing them, and gets its brown color from dense mitochondria
- Cold shock proteins are activated only in the cold and help repair damaged proteins as we age
- Cold exposure increases leucocytes and monocytes in new practitioners, while adapted swimmers show lower baseline levels indicating reduced inflammation
- Always end contrast therapy sessions on cold to force the body to heat itself up, increasing metabolism
- Nasal breathing during cold immersion helps shift from sympathetic fight-or-flight to parasympathetic calm
- Cold exposure triggers dopamine release identical to exercise-induced dopamine, increasing stress resilience and pleasure sensitivity
- The body adapts to cold exposure quickly, with recovery time shortening as one becomes more practiced
- Coffee consumption can nudge beige fat cells toward becoming metabolically active brown fat
Key Moments
Brown fat burns calories instead of storing them
Shawn Stevenson introduces brown adipose tissue as a special fat that burns fat for fuel rather than storing it, and how cold exposure is the key to activating it.
"There's a special kind of fat that has been recently discovered called brown fat or brown adipose tissue. And this fat, funny enough, it actually burns fat for fuel rather than being very, very good at storing it."
Cold shock proteins repair damaged cells and slow aging
Dr. Soberg explains how cold shock proteins are uniquely activated by cold exposure and play a critical role in repairing damaged proteins that accumulate with aging, complementing the effects of heat shock proteins.
"there are cold shock proteins which are different and activated only in the cold. They have overlapping efficiency to activate or making the cells stronger and repair the cells, repair the proteins which get damaged with years."
Cold exposure improves insulin sensitivity through brown fat activation
Dr. Soberg details how cold immersion lowers inflammation and increases insulin sensitivity by activating brown fat, which helps clear glucose from the bloodstream faster and reduces risk of type 2 diabetes.
"Yeah, so you can say that is what's needed. If we can lower the inflammation, you need to increase your insulin sensitivity. And you could do that by, well, moving your muscles. So of course, exercise has already been shown to modulate your inflammation in your body and also increase insulin sensitivity. But you can also activate your brown fat, which is all part of your metabolism. So increasing your insulin sensitivity will make your cells in your body more sensitive to insulin, of course, and then you will get faster rid of the glucose that is floating around in your bloodstream. So if you can do that faster, your body can do that faster, you will decrease your risk of diabetes, type 2 diabetes, which is a huge problem and it's a growing problem. And with that, also mental diseases or depression is associated with or obesity is associated with also having a higher risk for depression. It all comes down to the inflammation part of it. So if you increase your insulin sensitivity by activating your brown fat, so your muscles exercise is excellent. So it's just, yeah, just part of your, you can say your regime for lowering your stress and lowering your inflammation. So if people want to today to do something good for themselves, they should think about lowering the inflammation in the body because if they do that, then they will prevent a lot of diseases which is increasing today. So now that we know that cold immersion can improve our metabolic health, you're also tying this back to our mental health. And this is so important. Are there other aspects of cold immersion that can improve our mental health? Does this influence things like neurotransmitters, maybe like dopamine, for example? Yeah, so it seems that studies have shown that you can increase dopamine by 2.5 fold about if you go into cold water. So just one to two minutes is actually enough. And it also increases no adrenaline by 2.5 fold and actually more in some people. If you stay in the water, if you can build that up to one to two minutes, it takes a little bit of practice. I just want to say to all of those who haven't tried this, you have to practice this. Of course, it takes a few attempts before you can get up to one to two minutes. But if you can increase those neurotransmitters in your brain, you will also have a changed mindset for also going into the world because you are more focused. You have more drive because of dopamine. You also have an increase in endorphins, which will also make you more positive to whatever you meet in your daily life. And also the noadrenaline will give you energy. So when you put all these things together, it should be giving you a more positive mindset, right? So I think this is something that needs to be studied more, I think. But I'm very happy to actually pull up a paper here from 2023. It was published in January by a research group in the UK where they looked at psychological traits when people have their subjects in the study, submerging to cold water. They scanned the brain before and then after the cold plunges and they found and give them an explanation. And people have their subjects in the study. Submerge into cold water, they scanned the brain before and then after the cold plunges and they found and give them a questionnaire. And they found that they had changes in anxiety. So they were less anxious. They also, they were more confident and they felt just generally more positive to the world. So it's just all these questions. There were more results from that study, but these were just some of them, which I think boils down to if you feel more confident, you can do a lot of more things because confidence is really important in this world to pursue what you want to do. And it takes a really positive mindset also to do that. And it's the outcome of a lot of things adding up that you have that confidence, right? So I think that for mental health, this has a strong potential as well. So this study really shows that something changes when you go into the cold water, something changes in the brain. And that's because of these neurotransmitters. And these are functional MRI scannings of the brain. So people can go and look that up in the paper if they want to. Absolutely. And of course, if people are watching the YouTube version of the show, we'll put the study up for people to check out. But I don't want to go past one of the things that you said here. You said essentially that this practice of cold exposure sensitizes your brain to more pleasure. It makes your brain more sensitive to the good stuff that's happening and increases your resilience to what we might deem to be negative."
Dopamine from cold exposure mirrors exercise benefits
Cold immersion triggers dopamine release that is the same as exercise-induced dopamine, sensitizing the brain to pleasure and increasing overall stress resilience.
"And that is very similar. No, scratch that. It is the same as what you get from exercise."
Always end contrast therapy on cold to boost metabolism
Dr. Soberg recommends always ending contrast therapy sessions with cold rather than heat, as this forces the body to generate its own heat through brown fat activation, thereby increasing metabolism.
"if you do that by time when you have adapted a bit, you quicker increase your heat in your body by activating the brown fat when you end on the cold. So this is going to force your body to heat up. It's going to increase your metabolism. So that's why I always say end on the cold."
Use nasal breathing to shift from fight-or-flight in cold water
Dr. Soberg explains how nasal breathing during cold immersion activates the parasympathetic nervous system, helping practitioners stay in the water longer and adapt more quickly to the cold stress.
"But adaptation comes very quickly. So you can use nasal breathing and try to do that at least by lowering your breath in that way and switching from the sympathetic activation, the fight and flight, to the parasympathetic activation. And when you are able to do that, then you will be able to stay in the water for maybe up to a minute or maybe two minutes, and then you don't have to stay anymore. But that is the key is your breathing. The first time, second time, and third time, you will gasp for air. And that's probably just how it is, but you can try and focus on your breathing. That's going to help you. In the book, you talk about how it's easier to control your breathing when you get your full body into the water quickly versus doing it an inch at a time. Yeah. I mean, I would like to moderate that a little bit because I think there is one way to do it is just to get in, just to get it over with. And I mean, I did that. I just went in up to my neck and gasped a lot the first few times that I tried that. But I also tried something else and that was like going into the cold water. It's because the temperature in the sea where I swim in Denmark varies a lot."
