Proponents of cold exposure say it’s not only a great way to lose weight but also to improve mental health, increase libido or reduce type 2 diabetes risk among other health and well-being benefits. A lot of these claims are often based on personal experience. Do they hold up when confronted with scientific literature? A team of researchers from The Arctic University of Norway decided to find out.
There are many different benefits of cold exposure
They reviewed all the research evaluating whether voluntary exposure to cold water impacts health in humans. They excluded studies where participants wore wet suits and where water temperatures were above 20°C (68°F). They included studies looking at both established winter swimmers and people with no previous winter swimming experience. The 104 studies that made it into the review showed significant positive effects of cold-water swimming in several areas.
- Activation of brown fat tissue. Brown fat tissue burns calories to help maintain body temperature unlike regular white fat tissue, which mainly serves as a store of energy.
- Preventative effects for cardiovascular disease.
- Positive impact on the immune system. Tolerance to stress and respiratory infections.
- Prevention against insulin resistance. Improved insulin sensitivity and increased production of adiponectin, a protein that protects against insulin resistance and diabetes.
- Improved mental health.
“From this review, it is clear that there is increasing scientific support that voluntary exposure to cold water may have some beneficial health effects. Many of the studies demonstrated significant effects of cold-water immersion on various physiological and biochemical parameters. But the question as to whether these are beneficial or not for health is difficult to assess,” said lead author James Mercer.
Are the benefits due to cold water or something else?
The authors of the study noted that a lot of the available research involved small numbers of participants and large differences in water temperature and salt composition. They were also not able to say whether the observed health benefits are a result of the cold immersion or a self-selection bias. People that choose to go for icy swims may simply be overall healthier and more robust than those who avoid this hobby.
“Based on the results from this review, many of the health benefits claimed from regular cold exposure may not be causal. Instead, they may be explained by other factors including an active lifestyle, trained stress handling, social interactions, as well as a positive mindset. Without further conclusive studies, the topic will continue to be a subject of debate,” commented Mercer.
The study also warns about possible health risks of cold-water immersion related to hypothermia and shock from the cold. To mitigate these risks, it’s advisable to follow a progressive acclimatization program, preferably under the supervision of more experienced cold-water swimmers.