Cold water bathing can reduce “bad” body fat in men and reduce the risk of diseases such as diabetes. International Journal of Circumpolar Health.
The authors say many of the 104 studies they analyzed show that cold water swimming has a significant effect on “good” fats, which help burn calories. It can protect against obesity and cardiovascular disease, they add.
However, the study did not provide a general conclusion on the health benefits of cold water bathing, an increasingly popular hobby.
Most of the available studies involved small numbers of participants, often of the same sex, and varying in water temperature and salinity. In addition, it is not clear whether winter swimmers are naturally healthier, says a scientific expert team consisting of study authors from UiT Norwegian Arctic University and the University Hospital of Northern Norway.
“It is clear from this study that there is growing scientific support that voluntary exposure to cold water may have some beneficial health effects,” says lead author James Mercer from UiT.
“Many studies have demonstrated the significant effects of cold water immersion on various physiological and biochemical parameters. However, the question of whether these are beneficial for health is difficult to assess.
“Based on the results of this study, many of the health benefits claimed to be associated with regular colds may not be causal. Instead, they may be explained by other factors, such as an active lifestyle, trained stress management, social interaction, as well as a positive mindset.
“Unless further conclusive investigations are conducted, the topic will continue to be a matter of debate.”
Weight loss, better mental health, and increased libido are among the many health and wellness claims made by followers of regular cold water immersion or anecdotal.
This activity comes in many forms, such as cold water swimming in winter, and is a topic of increasing interest around the world.
The main purpose of the study was to determine whether voluntary exposure to cold water affects human health. The methodology involved a detailed search of the scientific literature.
Studies in which participants wore wetsuits, were accidentally immersed in cold water, and had water temperatures greater than 20 degrees Celsius were not considered.
Topics covered by the reviewable studies include inflammation, adipose tissue, circulation, the immune system, and oxidative stress.
Immersion in cold water has a great effect on the body and causes a shock reaction such as an increase in heart rate.
Some studies have shown that cardiovascular risk factors actually improve in cold-acclimated swimmers. However, other studies show that the workload on the heart still increases.
The review provided insight into the positive relationship between cold water swimming and brown adipose tissue (BAT), a type of “good” body fat that is activated in the cold. BAT burns calories to maintain body temperature, unlike “bad” white fat, which stores energy.
Cold exposure to water or air also increases adiponectin production by adipose tissue. This protein plays a key role in protecting against insulin resistance, diabetes and other diseases.
Repeated cold water immersions during the winter months significantly increased insulin sensitivity and decreased insulin concentrations. It was for both novice and experienced swimmers.
However, the authors note that the profile of swimmers participating in the studies was different. They ranged from elite swimmers or established winter swimmers to those with no winter swimming experience.
Others were not strictly ice swimmers but used cold water immersion as a post-treatment exercise.
Education is also needed about the health risks of bathing in ice water, the authors say. These include the consequences of hypothermia and heart and lung problems often associated with cold shock.