What A Single Sauna Session Can Do For Your Immune System

We’ve written before about the health benefits of saunas, for example with regard to type 2 diabetes and Alzheimer’s disease: The Surprising Link Between Type 2 Diabetes & Alzheimer’s

And those aren’t the only benefits we’ve covered, as we also talked about the potential broader longevity benefits, though the science was a little less clear on that one as while there was an association with reduced mortality, there were a lot of covariate factors not controlled-for: Can Saunas Make You Live Longer?

But aren’t saunas risky for the health?

Well, like anything, they can be, but for most people they are statistically a lot safer than, say, taking a shower:

Saunas: Health Benefits (& Caveats)

So what’s this about immune benefits?

A team of researchers (Dr. Ilkka Heinonen et al.) from Finland (of course) did a study in which 51 adults with an average age of 50 underwent a 30-minute Finnish sauna session at 73°C (163°F), with body temperature, white blood cells, and 37 cytokines (immune-signalling molecules) measured before, immediately after, and 30 minutes after the session.

What they found, in few words: total white blood cell counts increased, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, although the timing of the increases and recovery varied by cell type.

This is important, because even just temporarily mobilizing white blood cells into the bloodstream can help immune cells patrol the body and detect potential threats, including bacteria and viruse—essentially, your body giving itself an immunological check-up that it wouldn’t have otherwise troubled itself to do.

Thereafter, neutrophil and lymphocyte counts returned to baseline within 30 minutes, while other immune cell populations remained elevated for all participants, and total white blood cell counts remained slightly elevated in women (that’s all good).

Meanwhile, average body temperature rose from 36.4°C to 38.4°C, without changing plasma volume. You certainly wouldn’t want it to stay like that, but that’s normal and expected in a sauna.

Interestingly, only 2 of the 37 cytokines measured changed significantly overall, although 18 significant associations were found between changes in body temperature and cytokine levels.

In other words: sauna bathing produced a short-term increase in circulating immune cells similar to the response seen during physical exercise 😎

All that said, it’s just one study and results need to be replicated before we can make very strong statements with confidence.

You can read the paper in full, here: Acute Finnish sauna heat exposure induces stronger immune cell than cytokine responses

Want to learn more?

To get the most out of your sauna use, check out:

Looking to warm up with a sauna this winter? Here are 5 tips to enjoy it safely

Take care!