The current science review indicates that an ice swim can reduce “bad” body fat, but other health benefits are unclear.
Immersing in cold water can reduce “bad” body fat in men and lower the risk of conditions such as diabetes. These are the findings suggested by a major scientific review published on September 22 a International Journal of Circumpolar Health, a peer reviewed journal.
According to the authors, many of the 104 studies they analyzed showed significant effects of cold water swimming, including brown fat, also known as “good” fat, which helps burn calories. They say this can protect against obesity and cardiovascular disease.
However, the review was generally inconclusive about the health benefits of cold water bathing, an increasingly popular hobby.
Much of the available research involved small numbers of participants, often of a single gender, and with differences in water temperature and salt composition. In addition, it is unclear whether or not winter swimmers are naturally healthier, says the scientific expert team of review authors from the Arctic University of Norway and the University Hospital of Northern Norway.
“From this review, it is clear that there is growing scientific support that voluntary exposure to cold water can have some beneficial health effects,” says 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 of whether or not they are beneficial to health is difficult to assess.
“According to the results of this review, many of the health benefits claimed for regular cold exposure may not be causal. Instead, they may be explained by other factors, such as an active lifestyle, trained handling of stress, social interactions and a positive mindset.
“Without further conclusive studies, the issue will continue to be debated.”
Weight loss, increased libido and improved mental health are among the many health and wellness claims made by followers of regular cold water immersion or derived from anecdotal cases.
Exposure to cold also appears to increase the production of the hormone adiponectin by adipose tissue. This protein plays a key role in protecting against insulin resistance, diabetes and other diseases.
This activity is the subject of growing interest around the world and takes many forms such as cold water swimming during the winter.
Determining whether voluntary exposure to cold water has effects on human health was the main objective of the review. The methodology involved a detailed investigation of the scientific literature.
Studies in which participants wore bathing suits, accidental immersion in cold water and water temperatures above 20 degrees Celsius were excluded from the review.
Topics covered by studies that were eligible for review included inflammation, the immune system, adipose tissue, blood circulation, and oxidative stress.
Immersion in cold water has a major impact on the body and triggers a shock response that includes an elevated heart rate.
Some studies have provided evidence that cardiovascular risk factors are improved in swimmers who have adapted to the cold. However, other research suggests that the heart’s workload still increases.
The review provided information on 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 that stores energy.
Exposure to cold water, or air, also seems to increase the production of the protein hormone adiponectin by adipose tissue. It plays a key role in protecting against insulin resistance, diabetes and other diseases.
Repeated immersions in cold water during the winter months significantly increased insulin sensitivity and decreased insulin concentrations, the review found. This was for both experienced and inexperienced swimmers.
However, the researchers emphasize that the profile of the swimmers participating in the studies did vary. They included a wide range of people, from elite swimmers and established winter swimmers to those with no previous winter swimming experience.
Others were not strictly ice bathers, but instead used cold water immersion as a post-exercise treatment.
According to the authors, education about the health risks associated with bathing in ice water is also needed. These include the consequences of hypothermia and the heart and lung problems that are often related to cold shock.
Reference: “Health Effects of Voluntary Exposure to Cold Water: A Continuing Topic of Debate” by Didrik Espeland, Louis de Weerd, and James B. Mercer, 22 Sep 2022, International Journal of Circumpolar Health.