This may be an unusual topic at least from this part of the world in Asia, where usually we are quite used to the heat and the hot weather. What I want to talk to you about today, is regarding the health benefits of COLD EXPOSURE.
Today I am here to tell you that there are definitely some health benefits with cold exposure, and doing this regularly like having cold showers, or going for a cold swim, can really help promote your health wellness, and help you towards the path of longevity.
Now why do we think this is the case? In biology, there is this concept known as ‘hormesis’.
This is basically a concept that proposes that our body will respond to low levels of stress in a favourable way. Exercise is a great example of this, and I think one most people can relate to. When you are doing exercise, actually your body is put under quite a bit of stress. Most people are familiar with the fact that their heart rate and blood pressure go up, but also your metabolism also promotes increased glucose output to your blood. All these in isolation are actually not good for your body, but fortunately, mother nature built into our body, several cascades of biological and physiological responses respond to these ‘stresses’ and after this period, will be very beneficial to your body in the long run. And I think most people can relate to that. When you are doing exercise, it can sometimes feel like hell, but afterwards, you do feel really good. Scientists believe that cold exposure kind of does the same thing to your body, and kicks off a whole load of physiological processes that actually really benefit your body.
Now when I think about the benefit of cold exposure, I often think about it into 4 different buckets. Over the last 10-15 years, we have actually gotten a lot of scientific proof about the benefits of cold exposure.
First - is the metabolic benefits. In healthy individuals, cold exposure can increase energy expenditure and increase the use of glucose and fatty acid in your body. Repeated exposures can lower fasting glucose and insulin levels and improve dietary fatty acid handling, even in healthy individuals. This is backed up by various scientific studies that there seem to be health benefits with regard to your metabolic status. Whilst the exact mechanisms are still to be elucidated, it is thought that the key player is in the role of ‘brown fat’. A type of healthy fat stored around the spine that acts as our body’s temperature regulator and is able to boost metabolism and can even aid blood-sugar response and weight control. The more we expose ourselves to the cold, the more brown fat cells we have. So it’s a case of “use it or lose it!”
Second - there are also definite health benefits in terms of your immune system. A few studies that have looked at this in detail, have reported that after a period such as 6 weeks of repeated immersions, an increase in the blood immune cells (such as IL6, and several T lymphocytes as well as B lymphocytes) was seen. A Danish study also reported fewer sick days when they looked at participants who had repeated cold showers.
Third - is the mental and psychological benefits. Cold exposure is really a sort of mental exercise in building resilience. To be able to adapt to cold exposure, you really have to endure the initial pain and suffering, which is really quite character-building, but more importantly, you are making that executive decision to do something that in the short term will cause pain (something in neuropsychology we call ‘top-down control’). When we do this we are telling our brain (specifically the deeper brain centres that regulate our reflexes) that our conscious part of the brain is in control. This is in fact the scientific basis of grit and resilience. To be able to come through that I think really helps to build your mental resilience. So you could say that “deliberate cold exposure is great training for the mind”.
On top of that, there is actually a lot of evidence that deliberate cold exposure helps with mental illness such as depression, anxiety, and stress alleviation. Cold exposure causes the prolonged release of dopamine. Dopamine is a powerful molecule capable of elevating mood, enhancing focus, and attention, just to name a few. Even short bouts of cold exposure can cause a lasting increase in dopamine and sustained elevation of mood, energy, and focus. In terms of stress reduction, in the long run, people think what cold exposure does is that it actually increases the threshold of your baseline physiological stress levels. In other words, if you're normally stressed by missing the bus or whatever, this level of stress after some cold exposure training may not have such a negative effect on your body’s physiology.
Fourth - is more for athletes, but we know that cold exposure really helps with recovery. I am an avid Tennis fan, and I used to follow Andy Murray (a British tennis player) a lot. One of the things that he used to talk about a lot is that after each match within 2 hours, he would religiously jump into an ice-water bath. And there is scientific evidence to really back this up. Studies have shown that it improves muscle power, perceived recovery, and decreased muscle soreness.
How do I do it?
Now to get into cold exposure again does not have to cost you money. If you don’t have access to the sea or a lake nearby, just try doing cold showers. Actually, there was a study that looked at people who basically have a normal hot shower, but at the end of the shower, they told them to either have 30s, 60s, or 90s of cold shower, just to finish off. This Dutch study in 2016 showed that actually, you don’t need to do it for long, and people finishing a daily shower with a 30-second blast of cold water actually reduced their sick days at work by 29%.
The only caution I would say is that, if you do the cold shower in the evening, because of the release of adrenaline and noradrenaline, this effect can be prolonged and can spill over to night time and could affect your sleep. If you try this, and find that this does, in fact, impact your sleep, then it is better to do this earlier in the day.
If a cold shower is still too much to take, you could always try cold water face immersion in a bowl of iced water. This stimulates the vagus nerve which links the gut and the brain and helps reduce inflammation and also produce positive physiological changes by stimulating the parasympathetic system and helping the body relax.