Woman swimming in ice water


As you might imagine, our team here at Tonic Health frequently hears various claims, counter-claims and counter-counter-claims, on the subject of what may or may not strengthen the immune system.

Just one of those supposed ‘immune boosters’ to have come to particular prominence in recent years is cold therapy. So, it’s worth asking ourselves whether it does or doesn’t live up to the hype.

Introducing the power of cold water

Cold water, it turns out, can be a hot topic. The term ‘cold therapy’ – also sometimes referred to as ‘cold water therapy’ or ‘cold hydrotherapy’ – is the practice of using cold water of about 15 degrees C to treat health conditions or stimulate benefits to health.

Recent years have seen a range of celebrities give it a go, including actor Zac Efron, comedian Kevin Hart and wrestler Ronda Rousey. But in any conversation about famous figures who have practised cold water therapy, it’s especially difficult to avoid talking about Wim Hof, the Dutch extreme athlete who – with his ‘Wim Hof Method’ – has done so much to pioneer and popularise it.

But let’s go back to the beginning – or perhaps not the very beginning, given that cold therapy has effectively existed in some form or another for thousands of years. Supporters of this technique have long said that it offers a wide range of potential benefits, including higher energy levels, improved circulation, better sleep, and reduced inflammation in the body.

The evidence for some of these claims is largely anecdotal, rather than necessarily scientific. So, let’s take a look at some of the studies that have been done over the years into this surprisingly time-honoured practice.

Some of the claims made for cold hydrotherapy are better-evidenced than others

You might have heard, for instance, that cold showers can help boost mood. Sure enough, an article published in the Medical Hypotheses journal in 2008 said that this could be the case due to cold water activating the sympathetic nervous system and making neurotransmitters like endorphins and norepinephrine more available.

This, it has been suggested, could make depressive symptoms less likely to be experienced after a cold shower. However, it’s important to emphasise that people shouldn’t be taking cold showers as an alternative to any depression treatment they have been prescribed.

It’s interesting, nonetheless, to see such case studies from recent years as this one, which saw a 24-year-old woman who had experienced anxiety and depression since she was 17 embark on a trial of weekly open-water swimming. Her symptoms decreased so much over time that she was eventually able to cease treating them with medication.

What impact could cold therapy have on immune health?

If you’re specifically interested in how to improve the immune system, you might have particular reason to consider the merits of cold therapy.

A Dutch study from 2014, for instance, looked into whether a combination of cold water immersion, meditation and deep breathing could enable people to voluntarily influence their own immune response. The findings pointed to the answer being “yes”.

Fast-forward to 2016, and the journal PLoS One published research indicating that taking cold showers may make people 29% less likely to call in sick for work or school.

But before you start giving it a go yourself...

...it’s naturally important to be mindful of how you can do so safely. We would urge you to consult your doctor before immersing yourself in cold water, so that you are properly aware of the risks.

People with serious heart conditions and weakened immune systems need to be especially careful about trying cold water therapy, given the risks of the body being overwhelmed by any sudden changes in heart rate and body temperature.

Remember, too, that you don’t have to do anything especially dramatic when trying cold water hydrotherapy for the first time. Simply beginning with a warm shower that you gradually drop to cold can be a good way of safely getting used to the experience.

And of course, we would also encourage you to never regard cold therapy as your sole or main way of supporting your immune health! Our Tonic Health drinks, for instance, are formulated to provide useful everyday vitamins and minerals for immunity, to help your body consistently feel and perform at its best – and we have plenty of other tips on how to strengthen your immune system.  

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