Cold showers have become increasingly popular, often presented as a simple way to improve physical health, strengthen the immune system and increase productivity. But what does scientific research actually tell us?
A randomized controlled trial published in PLOS ONE explored whether taking a cold shower every day could influence health and work-related outcomes. The study involved 3,018 adults between 18 and 65 years of age who did not routinely take cold showers. Participants were randomly assigned to take a hot-to-cold shower for 30, 60 or 90 seconds, or to continue showering normally. The intervention lasted 30 consecutive days, followed by a period during which participants could continue cold showering at their own discretion.
The results were intriguing. People who followed a cold-shower routine reported 29% fewer days of sickness absence from work than those in the control group. However, the researchers found no significant reduction in the number of days participants actually felt ill. In other words, cold showers appeared to influence work absence, but the study did not demonstrate that they prevented illness.
The researchers also reported that no serious adverse events related to the intervention occurred. Nevertheless, the findings should be interpreted carefully. The study focused on adults without severe comorbidities, and its conclusions do not establish that cold showers improve the immune system or provide broad health benefits.
Cold showers may therefore be an interesting habit for some people, particularly because they are inexpensive and easy to incorporate into daily routines. However, scientific evidence does not support presenting them as a universal health solution. As with many popular wellness practices, the most useful approach is to distinguish what research has demonstrated from what remains an attractive but unproven claim.
Reference: Buijze, G. A., Sierevelt, I. N., van der Heijden, B. C. J. M., Dijkgraaf, M. G., & Frings-Dresen, M. H. W. (2016). The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial. PLOS ONE, 11(9)
Serra Húnter Fellow of Sociology at Universitat Rovira i Virgili.
Former DAAD-Gastprofessorin at Julius-Maximilians-Universität Würzburg