Sauna sessions boost the immune system
A short stay in a sauna may provide a slight but significant boost to your immune system, according to new research.
Scientists in Finland found that just a 30-minute sauna session can temporarily increase the number of white blood cells (key players in fighting infection) circulating in the body.
The study, which included 51 adults with an average age of 50, suggests that the heat-based ritual may do more than just help you relax.
Participants participated in a half-hour sauna session that included a short cold shower break in the middle. Blood tests revealed that all types of white blood cells increased immediately after the session.
Most importantly, the two main groups (neutrophils and lymphocytes) returned to normal levels within about 30 minutes.
Rather than creating new immune cells, the sauna appears to activate those already stored in the body, sending them into the bloodstream where they are most effective.
Ilkka Heinonen, Research Fellow at the University of Turku Academy, said: “This may indicate that sauna bathing mobilizes additional white blood cells from the tissues into the bloodstream, where they are re-stored after the session. Such periodic release of white blood cells into the bloodstream is beneficial because when they leave their storage location, they can better patrol the body and respond better to pathogens.”
Researchers say this response mirrors what happens during exercise, when the body strengthens immune surveillance by increasing the movement of white blood cells.
The team also examined cytokines, which help regulate immune responses, but found no major changes overall. But there was something wrong.
Professor Jari Laukkanen, who led the study, said: “However, interestingly, many cytokine levels changed depending on how much body temperature increased during sauna bathing. No similar relationship was observed between white blood cell count and changes in body temperature.”
Although regular sauna use has long been associated with health benefits, experts warn that this research only examined short-term effects.
