A new scientific assessment reveals that taking a plunge in cold water may reduce ‘bad’ body fat in males and lower the risk of illnesses such as diabetes.
According to the scientists, cold water swimming has a substantial influence on ‘good’ fat, which helps burn calories, in many of the 104 research they examined. They note that this may protect against obesity and cardiovascular disease. The analysis, however, found equivocal on the health advantages of cold-water bathing, a growingly popular activity.
Much of the existing study used small numbers of volunteers, frequently of one gender, and with varying water temperature and salt content.
In addition, it is unclear whether or not winter swimmers are naturally healthier, say the scientific expert team of review authors from UiT The Arctic University of Norway and from the University Hospital of North Norway.
“From this review, it is clear that there is increasing scientific support that voluntary exposure to cold water may have some beneficial health effects,” states lead author James Mercer, from UiT.
“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.
“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.”
Weight loss, better mental health, and increased libido are among numerous health and well-being claims made by followers of regular cold-water immersion or arising from anecdotal cases.
This activity takes many forms such as swimming in cold water during the winter, and is the subject of growing interest worldwide.
The main aim of the review was to determine whether voluntary exposure to cold water has health effects in humans. The methodology involved a detailed search of the scientific literature.
Excluded from the review were studies where participants wore wet suits, accidental cold-water immersion, and water temperatures greater than 20 degrees centigrade.
Themes covered by the studies that were eligible for review included inflammation, adipose tissue, blood circulation, immune system, and oxidative stress.
Immersion in cold water has a major impact on the body and triggers a shock response such as elevated heart rate.
Some studies provided evidence that cardiovascular risk factors are actually improved in swimmers who have adapted to the cold. However, other studies suggest the workload on the heart is still increased.
The review provided insights into positive links between cold water swimming and brown adipose tissue (BAT), a type of ‘good’ body fat that is activated by cold. BAT burns calories to maintain body temperature unlike ‘bad’ white fat which stores energy.
Cold exposure in water — or air — appears also to increase the production of adiponectin by adipose tissue. This protein plays a key role in protecting against insulin resistance, diabetes and other diseases.
According to the review, repeated cold-water immersions over the winter months dramatically raised insulin sensitivity and lowered insulin concentrations. This was open to both novice and veteran swimmers.
However, the authors note out that the demographics of the swimmers who took part in the research varied. They varied from expert swimmers to experienced winter bathers to people who had never swum in the cold before.
Others were not exactly ice bathers, but employed cold-water immersion as a post-exercise therapeutic.
According to the authors, there is also a need for education about the health dangers involved with swimming in ice water. These include the effects of hypothermia, as well as heart and lung problems that are frequently associated with cold shock.