Ice baths and cold plunges have been brought into the limelight following Joe Rogan and Dr. Andrew Huberman's Podcast earlier this year about the health benefits of cold exposure therapy. A study published last year by Dr. Susanna Soeberg, an expert in cold and heat treatment, was cited in the Podcast.
When thinking about ice baths -- the first thing that comes to mind is cold exposure for athletic performance and exercise recovery. But according to Rogan and Huberman, as well as Soeberg's study and others, regular users subjected to cold therapy will reap the health benefits in the form of adaptive hormesis, regulating hormones relating to sleep, regulating energy levels, mood maintenance, faster recovery after training and improved mental processing.
In a separate study, the health benefits go even deeper. Researchers from the Karolinska Institute in Sweden showed that cold exposure could inhibit the growth of cancerous cells in mice and humans.
Researchers published their findings in the British weekly scientific journal Nature. Titled "Brown-fat-mediated tumour suppression by cold-altered global metabolism," they found that rodents with cancerous cells that were continuously exposed to very low temperatures, but above freezing, for 20 days, experienced an activation of their brown fat tissue, which burns energy rather than storing it, diminishing the tumors' energy supply.
"Similarly, cold exposure of tumour-bearing mice also markedly inhibited the growth rates of these tumour types," the study said.
New Scientist explained more about the study:
To eliminate the possibility that the tumour suppression was down to something other than the cold therapy, Cao [researcher Yihai Cao] and his team intervened in several ways. After surgically removing the cold-exposed mice's brown fat, or turning off the gene by which brown fat generates heat, tumour inhibition was absent.
The inhibition was also absent when the mice were fed a high-glucose diet, suggesting that the tumours' growth was inhibited by a lack of glucose. The team also performed a genetic analysis on the cold-exposed tumours, finding a decrease in markers associated with glucose consumption.
Then in the second part of the experiment, researchers exposed a group of six healthy humans to 61°F for 2 to 6 hours for two weeks. What they found was similar to the mice. Volunteers' brown fat tissue was activated.
A person with Hodgkin's lymphoma was continuously exposed to cold (72°F) for a week. The results also found brown fat became activated, and their tumors consumed less glucose over this period.
A lot more research in cold exposure therapy needs to be performed. In the meantime, the trend of ice baths and even heat exposure in combination has gone viral on social media after Rogan's podcasts.
... and Wim Hof, also known as 'The Iceman', has been leading the cold exposure movement for years.
You can be strong without thoughts, just existing in the stillness of the mind, well-nourished with the life-force, the blood flow, because your thinking brain isn’t dominating those resources. Breathe. Go out into the cold. Feel it. It will take you back into yourself.— Wim Hof (@Iceman_Hof) December 18, 2022
Do eu-stress? ❄️🤔 When taking a cold shower or an ice bath, you are challenging your body and exposing it to eustress, which is a positive stress. If you learn to focus and stay calm during the immediate stress of the cold you can also get less affected by other stressors. pic.twitter.com/hDRgXryxdk— Wim Hof (@Iceman_Hof) December 10, 2022