There are quite a few people who enter a sauna for relaxation, sweating or a feeling of cleansing, but a new study from Finland claims that a 30-minute stay in a sauna has a surprising health bonus: Strengthening the immune system.
According to the study, published in the journal Temperature, sitting for 30 minutes in a Finnish sauna at a temperature of 73 degrees led to an immediate increase in the number of white blood cells in the bloodstream, without causing significant inflammatory activation.
In simple terms, the body sends more “soldiers” of the immune system to patrol the body, without entering a state of over-alert.
What Exactly Did the Researchers Examine
The study included 51 Finnish adults with an average age of 50, most of whom had at least one cardiovascular risk factor such as high blood pressure, excess weight or high cholesterol, but without active heart disease.
The participants were instructed to sit in a Finnish sauna for 30 minutes, with a short cold shower break in the middle.Blood tests were taken before entering, immediately after exiting, and again 30 minutes later.
The main finding was clear: All types of white blood cells increased immediately after the sauna, especially neutrophils and lymphocytes, two central types in the body’s defense system.
Some of the cells returned to normal levels after about half an hour, while others remained slightly elevated for a longer time.
Why This Matters
The meaning is that the sauna does not “produce” new immune cells, but rather moves existing cells from the body’s reservoirs into the bloodstream.
This is important because when they are circulating in the blood, they can identify pathogens, viruses or inflammatory processes more quickly.
The researchers explain that this is very similar to what happens during physical activity: The body temporarily increases its immune “patrol,” which may improve the ability to identify threats earlier.
One of the interesting findings in the study is that there was no sharp inflammatory response. The researchers examined 37 cytokines, molecules that transmit inflammatory signals in the immune system, and found that most of them barely changed.
In other words, the sauna manages to activate defense cells without causing an inflammatory “storm.” This is exactly why the researchers believe this is a mechanism of improved immune surveillance, and not a response of the body to disease or infection.
Both for Beginners and Regular Users
Another interesting detail: There was no difference between people who use the sauna regularly and those who experienced it only occasionally. In other words, even new users received the same immediate immune “boost.”
This suggests that the body does not get used to it and stop responding, but continues to view each such sauna session as a positive physiological stimulus.
The researchers mention that large epidemiological studies from Finland have already found a connection between regular sauna use and a reduction of about 37 percent in the risk of pneumonia among those who used a sauna at least four times a week.
The new study did not examine actual diseases, but only the immediate response of the body, yet it certainly provides a possible biological explanation for the benefits observed over the years.
Despite the advantages, a sauna is not suitable for everyone. People with uncontrolled heart disease, low blood pressure, dehydration, febrile illnesses or pregnant women should consult a doctor before regular use.
People who take certain medications that affect blood pressure or heart rate should also be cautious.
In conclusion, a sauna has long been more than just a spa indulgence. The new study shows that even half an hour of heat can cause the immune system to “go out on patrol” quickly throughout the body, without triggering an unnecessary inflammatory response.
It is not a substitute for sleep, nutrition or physical activity, but it certainly appears to be another simple tool that can contribute to overall health.
Source:
www.jpost.com
