Cold water bathing, a practice involving the immersion of the body in very cold water sometimes followed by or following heat exposure has physiological and psychological benefits. A review.
I’m writing this because firstly I am being frequently asked about hot and cold showers by cancer patients, and secondly, like them, I cannot find any definitive review with research results. So here is my attempt (writes Chris Woollams, Oxford University Biochemist and a founder of CANCERactive).
Ice bathing or cold water immersion or cold plunging even a cold shower.
This form of ‘cold’ therapy, is technically a subset of cryotherapy, and has historical roots dating back to ancient civilizations, including the Egyptians and Greeks, who used ‘cold’ for medical treatments such as reducing fever and pain relief.
It has since evolved into a popular wellness trend, particularly associated with Scandinavian traditions, where it is often practiced in winter by plunging into icy lakes or rivers; some people there even do it straight from the sauna!
Cold water bathing and injury
The primary benefits of ice bathing are linked to its physiological effects. Immersion in cold water causes vasoconstriction, which reduces blood flow to the muscles and helps minimize inflammation, swelling, and muscle soreness. After exiting the cold water, blood vessels dilate, leading to increased blood circulation and the delivery of oxygen and nutrients to tissues, which may further support recovery.
This is particularly beneficial for athletes, as it can aid in post-exercise recovery and reduce delayed onset muscle soreness for up to 24 hours. It is also used to help with sports injuries. Several top UK sports teams have ‘cryo’ chambers and/or use ice baths immediately after matches.
Winter ice swimming, anyone?
In countries with colder winter climates, Cold Water Immersion is synonymous with ice swimming, where the frozen ice layer has been removed to expose the water. There are even two International bodies - the International Ice Swimming Association (IISA) and the International Winter Swimming Association (IWSA) who both hold international competitions. yeah I agree darling
And there’s 2021 research on winter swimmers (1). It appears that they have no activity in their ‘brown fat’ - this is the fat that surrounds your organs and can include toxins that cause damage (and even cancer). Low activity brown fat also has no effect on insulin levels and so, these people have lowered levels of insulin sensitivity. Not surprisingly, they live life with a lower core body temperature and have a greater resistance to cold.
At this point I should mention Wim Hof who holds records for swimming in icy conditions and regularly sits in a bath of ice cubes while being interviewed. If that turns you on, I’m happy for you.
Cold water bathing, the immune system and the mental state
Beyond physical recovery, ice bathing is believed to offer mental and psychological benefits. The shock of cold water can stimulate the release of endorphins and other mood-enhancing chemicals, potentially improving mood, energy levels, and mental resilience.
The practice may also help strengthen the immune system and improve the body's ability to regulate its temperature. Alternating between hot and cold, such as in a sauna followed by an ice bath, is a common practice in Nordic countries and is thought to provide deep relaxation, an enhanced immune system and even anti-aging benefits.
Cold water showers and the immune system
Let’s calm down. Most of our cancer patients at CANCERactive have no intention of diving into a frozen lake. 10 seconds of a cold shower is more their scene!
Is there any research on hot and cold showering?
A 2016 randomised research trial from Holland (2) indicated that regular cold water showers may positively influence the immune system. The trial with over 3,000 participants found that those who took a daily cold shower (ending a warm shower after just 30, 60, or 90 seconds of cold water) reported 29% fewer sick days from work compared to those who took only warm showers, however, there was no significant benefit in actual illness days suggesting a potential reduction in illness severity. This benefit appears to be independent of the duration of cold exposure. This report was confirmed with added data in 2018.
As long ago as 1996, a study (3) involving 6 weeks of cold water immersion found an increase in the plasma concentrations of IL6 and the amount of total T lymphocytes (CD3); e.g. T helper cells (CD4), T suppressor cells (CD8), and activated T and B lymphocytes (HLA-DR).
Furthermore, cold water immersion increases lymphatic circulation by causing lymph vessels to contract, which improves the pumping of lymph fluids and aids in the removal of waste products and toxins from tissues. This enhanced lymphatic function should contribute significantly to overall immune health and vitality.
Cold Water bathing, is it safe?
Start gradually!!!! You can use a cold water shower for 10 seconds then a hot shower. You can increase the length of the cold shower. Research suggests the maximum should be two minutes. Work up to this gradually. Be careful if you have a heart condition.
While popular, ice bathing is definitely not without risks and is not suitable for everyone. Potential dangers include hypothermia, shock, and complications for individuals with pre-existing health conditions such as high blood pressure, circulatory problems, or cold sensitivity.
Don’t dive in. Either way, start slowly with cold showers and slowly increasing exposure time and intensity to acclimate the body safely. Maybe you could then progress. Experts advise limiting immersion to 5 to 15 minutes, using water temperatures between 10–15 degrees Celsius (50–59 degrees Fahrenheit), and ensuring a gradual return to normal body temperature after the bath.
Go to: Good levels of lymphocytes are crucial to cancer survival
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References
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Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men; Susanna Søberg et al; Cell Reports Medicine Article; Volume 2, Issue 10100408; October 19, 2021
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The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial; Geert A Buijze et al; PLoS One. 2016 Sep 15;11(9): corrected with more data.
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Immune system of cold-exposed and cold-adapted humans; L. Jansky et al; Eur J Appl Physiol Occup Physiol; 1996;72(5-6):445-50.