I've always been a fan of the cold. Snow in Christmas. Abdominal snowmen. Fangirling over Elsa. Sleeping with the AC on... in winter. Obsessing over this song and totally being on #TeamSnowMiser. There's just something about the cold that feels fresh. Having a bit of a chill immediately clears my head and beckons resilience. It's hard to be lethargic when frigid! No better way to turn off brain fog than stepping into a dark night in the dead of winter, or blasting yourself with a cold shower (my recent obsession!)
THE HEALTH BENEFITS OF COLD EXPOSURE
As it turns out, there's something to my frosty love affair, since cold exposure has been shown to support numerous health benefits all throughout the body. Let's just jump in, shall we?
FAT BURNING THERMOGENESIS
Cold exposure forces the body to implement actions to warm itself up. AKA: burn calories to generate heat! Studies show cold exposure can "raise" the metabolism 3–5 fold above its resting rate. This materializes as both shivering and non-shivering thermogenesis. Both are designed to warm ya up, and burn calories in the process, but they're a bit different in modalities. While the shivering version can yield the highest rate of increased calorie burning (reaching the 5 fold side of things), it's also notably the #notfun type characterized by incessant muscle contractions. Ya know, the whole shivering thing!
Nonshivering thermogenesis, however, is much more pleasant, still increases the metabolism by around 30%, and may be epic for our health! It specifically increases the production and activation of brown fat in the body. Now before you're like #omgcoldmakesmefat!, let us pause. Because guess what! Brown fat actually burns fat! As it goes, our bodies harbor different types of fat: primarily white and brown adipose tissue. In today's often overfed and sedentary society, we tend to harbor a lot of that first sticky white fat, which jealously holds onto calories, is easy to store, and typically hard to burn. Brown fat, however, is a special type of fat with more mitochondria (the energy burning part of cells), and which helps us stay warm. With more brown fat, we actually burn more calories. Brown fat can also burn both carbs and fat, though typically favors more fat.
A 2018 study, Physiological responses to acute cold exposure in young lean men, analyzed 11 men in their early 20s, to explore the whole cold exposure thermogenesis thing. The guys were placed in a cool room (around 67 degrees Fahrenheit) and wore cold vests which dropped to around 30 degrees Fahrenheit. They were monitored until shivering occurred. This was so, presumably, all increased energy burned up until that point would be thanks to non-shivering thermogenesis. Data was compared before an individual's cold exposure, at the 31% mark into the experiment, at the 64% mark, and finally when shivering started - which averaged around an hour and a half.
Most of the changes occurred in the initial 30 minutes. From the time the guys were warm, until they were 31% of the way to shivering, they began burning more fat, with researchers speculating the increased metabolism coming from their brown fat burning fat within the cells, as well as in the bloodstream. As the men got closer to shivering, they felt more uncomfortable as their skin temperature dropped. (Notably, they didn't experience discomfort in the skin surrounding the lymph nodes in the neck, which featured no change in temperature. So. Random.) While shivering ramped up metabolism for the men even more, this was when the experiment ended.
The fact that the cold exposure instigated the most abrupt changes in fat burning in the initial, less "uncomfortable" part of the experiment, is promising for using cold therapy for health benefits - without utilizing seemingly unbearable temperatures. And while the men didn't burn a shocking amount of calories during the experiment (around an extra 21 calories per hour), they still experienced the activation of the aforementioned brown adipose tissue, which tends to increase calorie burning long term. Furthermore, other studies have shown mild cold may discourage body fat deposits as well as obesity. In fact, in a fascinating 1986 study, rats placed in chilly water for a few hours per day ate around 50% more calories than the warm rats, yet weighed less than the control rats, while living longer to boot! Telling!
While the ramped-up fat burning during cold temperatures is thought to be controlled by the automatic sympathetic nervous system (which is strengthened from such temperature challenges), recent research (which we'll get to in a bit!), is painting a more nuanced picture.
Time for some irony.
How many people think the cold weather is often the source of their flu? Contrary to popular belief, increased sniffles during the wintry season is actually more likely due to increased time indoors (ironically, out of the cold), which encourages more exposure to viruses and bacteria from others.
In reality, cold exposure can be fantastic for the immune system! Studies have found that cold exposure naturally upregulates catecholamines and important signaling molecules of the immune system, including white blood cells, lymphocytes, T helper cells, and suppressor cells. While a single bout of cold exposure doesn't seem to have that much of an immediate effect, consistent cold exposure encourages these changes over time. Slow and steady wins the race!
A 2015 study split a whopping 3018 individuals into 4 groups: a control group of normal hot showerers, and groups who followed their hot showers with 30, 60, or 90 seconds of a cold shower. The researchers found that those who took cold showers experienced 29% less sickness! (Though, interestingly, it didn't change who actually showed up to work - sickness or no.) The cold showerers also reported beneficial effects on their quality of life, productivity in their jobs, levels of anxiety, and ability to handle adverse situations. Basically, it boosted that elusive thing known as resilience.
BLOOD SUGAR REGULATION
Cold exposure may also regulate blood sugar levels, further encouraging appetite regulation as well as health in general. Proposed mechanisms include raising a protein called adiponectin, which is important for insulin sensitivity, as well as modulating glucose use in the body.
With all the increased beneficial biomarkers from cold exposure, perhaps it's not surprising that it just may lengthen life in general. Various studies have found cold exposure boosts the lifespan of rats, mice, and fish. Chronic inflammation is often behind many experienced health issues, and cold exposure has been shown to be highly anti-inflammatory, thanks in part to increased levels of the anti-inflammatory protein adiponectin. Cold exposure may also reduce damage from otherwise damaging byproducts of energy generation. Think: Excess heat and reactive oxygen species.
Increased longevity from cold exposure could also be due to hormesis in general. This refers to beneficial stressors (like exercise, fasting, and of course, cold exposure!) which ultimately make an organism stronger.
THE GENDER CAVEAT
Of course, we're all unique snowflakes, and cold exposure may affect each person differently - including based on gender! While a 2014 study, for example, found that immersion in 57 degree Farenheit water for up to almost 3 hours created similar rates of cooling in both males and females, other psychological responses varied. Women, for example, experienced more of an insulative reaction, while men experienced more shivering, heat production from their metabolism, and increases in epinephrine and some immune factors. In animal studies, however, females have been shown to live longer from cold exposure.
THE WORKINGS OF WIM HOF
For the ultimate proof that cold exposure is where's it's at, look no further than the seeming human superpower known as Wim Hof, aka: The Iceman. Wim has accomplished an array of #nobigdeal feats, including climbing Mt. Everest in shorts, hiking Kilimanjaro barefoot, and racking up 26 Guinness World Records for fun things like taking the longest ice bath.
In his younger years, Wim formed a friendship with the freezing climate of the Netherlands, which seemed to grant him mental and physical vitality. With his increasing engagements in such clandestine activities like jumping in freezing canals, Wim had a revelation: the cold would affect the way he was breathing. He began replicating the breathing techniques inspired by the cold, ultimately coming up with his Wim Hoff Method, purported to supercharge and alkalinize the body, yielding epic resilience. The method combines cold exposure, meditation, and Wim's breathing technique: a 20 minute exercise of full breaths in, shallower breaths out, and intercepted with periods of breath holding. (For the complete protocol see this video).
And it turns out the cold exposure, breathing, and meditation isn't just a mental thing. Studies on Wim's work are revealing the techniques have an almost shocking effect on the body, including alkalizing the blood to hyper saturated blood oxygen levels. Recent findings from Wim's methods have revealed that what was presumed to be 100% oxygen blood saturation is actually not quite 100%!
But it gets even crazier!
By implementing Wim's breathing method followed by meditative thinking about the immune system and what you want to address or heal in the body, Wim has shown a person can literally change his or her body's response to disease, materializing physiologically as a decreased inflammatory response to toxins, while also boosting the immune system's innate power. It's like, instead of a person #freakingout when an invader enters the scene and making a mess in the process, they instead remain calm, cool, and collected, effectively handling the situation without fear (and notably without shooting themselves by accident in the process.)
STUDY 1: WHM AND THE IMMUNE RESPONSE
In a 2012 case study, researchers conducted 3 experiments to analyze Wim's nervous system and immune response to cold and immune stress, putting to the test his "claims that he can influence his [autonomic nervous system] and also his immune response" through his technique. (I can just see the scientists raising their eyebrows!)
In the experiments, Wim practiced his meditation technique during 80 minutes in ice, as well as while infused via IV with lipopolysaccharide (LPS), or bacterial endotoxin. LPS forms the outer membrane of gram-negative bacteria, and is extremely toxic to us human hosts, resulting in intense inflammatory immune responses and the accompanying flu-like symptoms. In other words, they injected Wim with stuff to make him sick. (You couldn't pay me to do this!) His cytokine and immune response was then compared to 112 individuals who had previously undergone such endotoxic experiments.
During the ice challenge, Wim experienced higher cortisol levels and a lower, notably more anti-inflammatory immune response than typically exhibited, categorized by less inflammatory cytokines (chemicals and messengers involved in the immune response.) During the endotoxin experiment, he generated higher levels of the adrenal hormones known as catecholamines - predominantly norepinephrine - and cortisol than any of the 112 other patients studied to date. As the researchers noted, it was a "remarkably mild innate immune response in vivo." He also expressed severely reduced flu-like symptoms.
So what does this all mean?
Ya see, while the stress and immune response is vital for keeping our bodies healthy and capable of combatting invaders, it is often on high alert in today's toxin-saturated environment. Prolonged activation of the immune system can lead to chronic inflammation and net damage to the body, encouraging many autoimmune conditions. (Think: Shooting yourself in the foot!) Recalibrating the immune system, and actually calming its response, can therefore be key in boosting our immune system's function for the better.
Wim's response in the study insinuated he was using his techniques to actually willingly control his body's physical stress and immune response, tapping into systems largely thought to be autonomic in nature. The increase in catecholamines and its tag-along-friend cortisol, actually act as immunosuppressants with anti-inflammatory properties. (Yes, cortisol does have its place in acute immune reactions! We just don't want it chronically activated. Timing is everything!)
Of note, Wim's stand alone meditation resulted in less immune attenuation than when coupled with the stress of the cold or the bacteria, indicating it was somehow the combination of the acute physical stressors with his mental technique which provided such valuable alterations in the immune system.
As the researcher concluded, Wim's "concentration/ meditation technique seems to result in a consciously controlled stress response, characterized by sympathetic nervous system activation and subsequent catecholamine/cortisol release. This response seems to attenuate the innate immune response. The individual claims that he can teach others this technique. Therefore, further investigations should establish whether the results obtained can be reproduced in larger groups of individuals."
That last part is key, because Wim consistently maintains that he is not, in fact, an anomaly, but rather that his love affair with the cold inspired a mind-body connection epiphany supporting epic health, which is available to anyone utilizing the technique! According to Wim, anyone can achieve these states - which often take years if not decades for your typical yogi or buddhist monk - in a mere few days... if not a single session!
And it turns out, the science is starting to back him up!
STUDY 2: WHM IN OTHERS
A 2014 trial set out to put Wim's methods to the test in others, to see if his techniques truly could influence anyone's immune system. In the fascinating study, 18 healthy young Dutch males were trained in Wim's techniques for 10 days - in part by Wim himself! (Jealous!) These techniques included intense physical training and stressors: cold exposure (30 minutes barefoot in the snow, 20-30 minutes barefoot and/or bare-chested in the snow), submersion in ice-cold water, and hiking snowy mountains in only shorts and shoes, as well as strength training and yoga. The participants also trained in Wim's visualization meditations and two different breathing exercises:
- 30 breaths to create what amounted to hyperventilation, followed by 2-3 minutes of holding their breath (for however long they desired). This was finalized by one last deep inhalation held for 10 seconds, with the cycle repeated.
- Cycles of deeply inhaling and exhaling, followed by tightening all body muscles while holding their breath for 10 seconds.
12 of the males were then randomly chosen to undergo the test experiments along with 12 non-trained males. Like in the 2012 experiment on Wim, the participants were injected with toxic bacterial endotoxin, and monitored to see how their immune systems reacted to the poison. The trained individuals utilized the breathing techniques during the exercises.
The researchers found that the bodies of the trained volunteers became extremely alkaline, with increased levels of epinephrine, which, as discussed in the first case study, can downregulate the inflammatory immune response. In fact, the trained participants' levels of epinephrine while practicing the breathing during the endotoxin exposure, reached levels higher than those measured in bungee jumpers! And while the untrained guys experienced the expected intense inflammatory response to the endotoxin, the immune systems of the trained individuals exhibited a more beneficial profile, with more anti-inflammatory cytokines (IL-10) and less pro-inflammatory ones (TNF-α, IL-6, and IL-8). While cortisol levels were similar in both groups, they went back to normal levels faster in the trained males, who also experienced less flu-like symptoms, with faster resolution of fever.
In other words, the immune systems of those utilizing Wim's techniques responded to the invading bacteria to "fix" the situation, but did so in a much more controlled, less damaging manner.
The researchers hypothesized that the change in their immune system was likely not directly from the created alkaline state, since previous studies have shown that hyper-alkaline blood states compared to acidic blood states are not typically associated with anti-inflammatory reactions. (Though I bet Wim would beg to differ?) Instead, they credited the increased epinephrine as the key, while admiting that other parts of Wim Hof's method as a whole (the cold exposure, meditation, breathing, etc.) might have been involved.
As the researchers concluded,
"This study demonstrates that the in vivo innate immune response can be voluntarily influenced in a nonpharmacological manner through voluntary activation of the sympathetic nervous system. we demonstrate that voluntary activation of the sympathetic nervous system results in epinephrine release and subsequent suppression of the innate immune response in humans in vivo. These results could have important implications for the treatment of conditions associated with excessive or persistent inflammation, such as autoimmune diseases."
Perhaps the most fascinating finding from the experiment, was not so much even the change in the immune system itself, but rather the fact that the participants did, in fact, literally change an "autonomic" immune response seemingly by their own consciously-controlled methods.
Of course, the question is... just how are these changes taking place? Is it all the body? The brain? Both?
Thankfully, recent 2018 findings - from another case study on Wim - is beginning to paint a clearer picture!
STUDY 3: WHM METHOD AND THE BRAIN
The groundbreaking "Brain over body - A study on the willful regulation of autonomic function during cold exposure" was part of a series looking at how the brain reacts to temperature-challenging conditions. In the trial, Wim wore a full body suit which reached frigid temperatures, and his brain and body were analyzed via fMRI (functional magnetic resonance imaging) and PET (positron emission tomography) respectively, while he both practiced and didn't practice his techniques. The results were compared to a control group of individuals not practicing the methods.
The researchers found that Wim could willingly change his literal skin temperature in response to the vest: warming himself up from the inside! His breathing techniques increased the activity of his sympathetic system, and his rib muscles utilized more glucose to create heat and distribute it to the lungs and circulating blood around them.
Of course, if you read the earlier part of this post, you may be thinking this isn't surprising, given my discussion of brown fat's activation by cold temperature. However, Wim's brown fat wasn't remarkably involved in the warming response! Rather, it would seem his warming technique was literally coming from his mind! (The researchers noted this might explain in part his historical ability to withstand frostbite amidst extremely rigid conditions!)
And while the researchers had suspected any brain activity involved in Wim's thermal regulation would come from parts of the brain responsible for body temperature (the anterior insula), the parts of brain at use were actually in the periaqueductal gray (PAG), which controls pain and cold perception. It would seem that Wim - through his technique - was able to encourage the creation of feel good compounds (such as opioids and cannabinoids) to combat the cold - a self built pain-relieving response! Wim effectively activitated higher-order parts of his brain typically connected to self-reflection and perseverance in physically stressful circumstances.
As the researchers concluded, "Our results provide compelling evidence for the primacy of the brain (CNS) rather than the body (peripheral mechanisms) in mediating the Iceman's responses to cold exposure."
So not only can cold exposure benefit the body in a myriad of ways as discussed throughout this post, but it looks like you can also make it literally more bearable with the right mindset, which will, in turn, boost other aspects of health! The work on Wim is therefore not only relevant to health advances for the immune system and autoimmune conditions, but also potentially psychiatric areas involving mood regulation and anxiety, thanks to its mood-boosting power.
The power, truly, is in your mind!
This blog post wouldn't be complete without a nod to a device which has truly revolutionized my sleep with the power of cool temperatures! As I discuss in my interview on The Melanie Avalon Biohacking Podcast with Fusion scientist sleep expert Tara Youngblood, a cool body temperature can be key on a cellular level to actually instigating restful sleep! (We also discuss why there likely are "morning people" and "night people" thanks to genes,and why there's no one right amount of sleep for everyone!) I simply had to interview Tara, because her invention of the ChliPad - a mattress topper which uses water to cool down or heat up to regulate your body temperure- has truly change my life. I don't know how I would sleep without it! You can get the episode, transcript and shownotes here! You can also Use The Code MA25 For 25% Off The Chillipad, Or The Code MA15 At Chilitechnology.com For 15% Off Their Ooler!
SO WHAT DOES IT ALL MEAN?
Hopefully this post has ya thinking twice before reaching for that sweater. After all, it's hard to say no to the array of health benefits held in a state of simply enduring an environmental factor. As I say in What When Wine, I really am a fan of health benefits that sort of just happen in a "Who, Me?" type way, especially ones which provide maximum bang for your buck and make you more powerful on the flip side. So I don't know about you, but I'll continue to embrace cold exposure for all its worth, in both its most accessible and slightly more boutique ways. Here are some ways to implement some more frigidness in your life (in body, not spirit!)
- Keep the AC a little chilly - especially in the winter!
- Underdress and bring a jacket: You can always add layers but can't always take them off. (well... ya know... )
- Linger a bit in the walk-in produce rooms in Costco like it's #theplacetobe
- Begin taking cold showers. Start by ending your shower with 10 seconds of cold water. Gradually add 10 seconds as you get more accustomed, working up to around 90 seconds. I've been doing this for a few weeks now and it's truly life changing! I'm currently at 50 seconds. It instantly clears my head, brightens my eyes, wakes me up, boosts my mood, and just makes me feel good throughout the rest of the day. I love using this waterproof timer - which can really make all the difference in implementing these cold blasts as a true habit in your life! (It sort of forces you to stay on track, and can motivate you to go just a *smidge* longer each time.)
- If you have access to it, try out some cryotherapy!
And of course, the cold exposure can be further boosted in combination with the discussed breathing and meditation techqnieus of Wim Hof - proof that facing physical stressors like the cold, in combination with powerful oxygenation, alkalization, and mind/body connection, can upgrade your life on all levels. And it's completely free, accessible, and not even very time intensive! We're talking way less time than the gym or other such health commitment, and it'll likely leave you feeling much better to boot!
So I don't know about you, but I choose to see the wintry beginnings of the New Year as the perfect time for rocking my inner snow bunny. Winter is coming, for completely better and not worse! You got this!
The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial
Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory"
Mid-life temperature-transfer effects on life-span of annual fish
Cold exposure reverses inhibitory effects of fasting on peripheral glucose uptake in rats.
Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory"
Do You Really Get Sick from Being Cold?
Transgenic mice with a reduced core body temperature have an increased life span
The Influence of Concentration/Meditation on Autonomic Nervous System Activity and the Innate Immune Response: A Case Study
Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans
"Brain over body"-A study on the willful regulation of autonomic function during cold exposure.