Is Saunaing Really That Good For You?

Introduction

First let’s talk about what it means for something to be good for us. For the purposes of this article, I want to use the premise that something is good for us if it can improve our healthspan. A commonly accepted definition of healthspan is the period of one's life spent in good health, free from the chronic diseases that are associated with and accompany aging. [1] Extending healthspan shortens the time spent in poor or debilitating health, moving it to the later years of your life (even later than usual). In 2021, about 2 in 10 deaths from Coronary Artery Disease happened in adults less than 65 years old. [2] Heart disease is the leading cause of death for men and women in the United States. One person dies every 33 seconds from cardiovascular disease, and about 695,000 people in the United States died from heart disease in 2021: that’s 1 in every 5 deaths. [2] Sauna use has strong evidence as a potential means to increase healthspan.

Sauna Use

Most people have an idea of what saunaing is, but let's talk very briefly about a few different kinds. Every sauna aims to elevate your core body temperature sufficiently to kickstart its innate healing mechanisms. There are a few main types of saunas; wet, dry, and infrared. Wet saunas basically work by keeping humidity high to prevent the body from cooling efficiently. Dry saunas are straightforward and heat your body through increased air temperature. Unlike the previous two methods, near infrared will heat you from the inside out. By using the shorter wavelengths of near infrared, the light can penetrate the skin to raise your core temperature more quickly versus the longer wavelengths of far infrared which are absorbed by water in the surface of your skin. This makes sessions faster, and allows for more comfortable air temperatures.

What Does Sauna Bathing Do?

Just like exercise stresses the body, so does raising your core body temperature. And just like exercise, that moderate stress acts as a catalyst that drives an adaptive response in the cells and tissues called hormesis. The exposure to heat in a sauna causes mild hyperthermia and induces thermoregulatory responses involving the endocrine, musculoskeletal, and respiratory systems working together to maintain homeostasis. One of the protective adaptive responses to heat stress is the increased expression of heat shock proteins (HSPs), present in all cells, which help prevent protein disorder/aggregation by repairing proteins that have been damaged, thus providing protection against chronic diseases. [3] HSPs basically act as a cleaning and maintenance service for your cells and make sure everything is in order and in good working condition.

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Heat exposure is also well known for its positive effects on cardiovascular health and its ability to lower the chance of all-cause mortality. Heat exposure can replicate some of the same responses experienced during exercise. Besides just sweating, heart rate may increase up to 100 beats per minute during moderate-temperature sauna bathing sessions and up to 150 beats per minute during hotter sessions, similar to the increases observed during moderate- to vigorous-intensity physical exercise [3] Regular sauna use, just like exercise, can reduce blood pressure, increase heart rate variability, and improve endothelial function. Men who attended a sauna bathing session two–three times per week reduced their cardiovascular mortality rates by ~30% and men who attended a sauna session four or more times per week reduced their risk by ~50% [4] Also, frequency of sauna bathing is inversely associated with all-cause mortality, with a 40% reduction comparing 4 to 7 sessions vs 1 session of sauna bathing per week. [4] When looking at neurological disease, men who reported using the sauna 4–7 times per week had a 66% lower risk of developing dementia and a 65% lower risk of developing Alzheimer's disease, compared to men who reported using the sauna only once weekly. [5]

Conclusion

There are numerous health benefits to regular sauna use. It acts to improve several aspects of overall body function including cardiovascular function, neurological function, immune function, and more. It is dose dependent, meaning the more you do it, the better it is for you. Aerobic exercise in combination with frequent sauna use has a synergistic effect on lowering cardiovascular-related mortality and all-cause mortality. [3] But even as a stand alone, sauna bathing has been suggested to be able to work as an aerobic training modality for those that may be unable to train in conventional methods. On top of exercise, nutrition, and sleep, I would argue saunaing is one of the next best things you could do to improve your healthspan.

References

1. Kaeberlein, M. How healthy is the healthspan concept?. GeroScience 40, 361–364 (2018). https://doi.org/10.1007/s11357-018-0036-9

2. Centers for Disease Control and Prevention. Heart Disease Facts. Available online: http://www.cdc.gov/heartdisease/facts.htm (accessed on 5 December 2023).

3. Rhonda P. Patrick, Teresa L. Johnson, Sauna use as a lifestyle practice to extend healthspan, Experimental Gerontology, Volume 154, 2021, 111509, ISSN 0531-5565, https://doi.org/10.1016/j.exger.2021.111509.

4. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Intern Med. 2015;175(4):542–548. doi:10.1001/jamainternmed.2014.8187

5. Tanjaniina Laukkanen, Setor Kunutsor, Jussi Kauhanen, Jari Antero Laukkanen, Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged Finnish men, Age and Ageing, Volume 46, Issue 2, March 2017, Pages 245–249, https://doi.org/10.1093/ageing/afw212