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A recent study from Finland reveals that spending just 30 minutes in a sauna can enhance the immune system by increasing the circulation of white blood cells. The research, published in the journal Temperature, indicates that sauna use mobilizes white blood cells into the bloodstream, which helps the body defend against pathogens and diseases.
Ilkka Heinonen, an Academy Research Fellow at the University of Turku and the study's first author, explained that sauna bathing "mobilizes additional white blood cells into the bloodstream from tissues, where they are then redeposited after the session." This periodic release of white blood cells is beneficial as it enhances the body's ability to respond to threats.
The study involved 51 adults, with an average age of 50, who participated in a 30-minute Finnish sauna session at 73°C. Blood samples taken before, immediately after, and 30 minutes post-session showed increased white blood cell counts, particularly neutrophils and lymphocytes, although these returned to baseline after 30 minutes. Monocytes, eosinophils, and basophils remained elevated.
While the study found little effect on circulating cytokine levels, Jari Laukkanen, who led the study at the University of Eastern Finland, noted that changes in body temperature during sauna bathing were associated with changes in cytokine levels. This suggests that heat stress and immune activation may partly mediate the health benefits of sauna use.
The study, however, has limitations. It focused on a single sauna session, and the authors suggest that regular sauna users might experience different results due to heat adaptation. Despite this, the findings underscore the potential immune-boosting effects of sauna bathing.
The research aligns with other studies, such as one discussed by Wasatch Mountain Sauna, which highlights the benefits of sauna use, including increased white blood cell production and enhanced natural killer cell activity. Regular sauna sessions are also associated with reduced stress and improved sleep quality, both of which contribute to a stronger immune system.