Saunas Boost the Immune System
By Jenna Greenfield MD
The current coronavirus pandemic is creating a lot of fears and questions. People are suddenly hyper-aware of measures to reduce infection transmission, and boost resistance to infection. While this pandemic will pass, these should be concerns at all times. The last 2 seasons report 35 to 45 million cases of the flu per year, and 35 to 61 thousand deaths annually. About 1 in 10 Americans will be infected with the flu each year, and while the fatality rate in this country is low (0.1%, less if you are young and otherwise healthy) (1), it can cause weeks of very unpleasant symptoms, and loss of income in many cases.
Heat Shock Proteins and the Immune System
Saunas, and heat therapy, have been proven to significantly increase cellular resistance to stress, including viral infections. When our cells are exposed to heat, they increase their levels of proteins called heat shock proteins, which increase the cells resistance to many types of stressors including heat, low oxygen, oxidative stress, toxicant exposure, and infection (2). Heat shock proteins have also been shown to have keys roles in the immune response, and boosting immunity. They have been shown to activate antigen presenting cells, the cells that present viral proteins to our white blood cells to initiate an immune response (3). Heat shock proteins can interact directly with viruses and regulate their entry into cells and viral replication (4). And heat has been shown to have a direct stimulatory effect on immune cells (5).
Heat Reduces Mortality in Sepsis
Heat, and heat shock proteins, have been shown to significantly reduce mortality in a rat model of sepsis, an overwhelming infection that is usually fatal. Rats that were treated with heat 16 hours prior to the induction of sepsis showed elevated heat shock proteins in the brain, heart, liver, muscle, white blood cells, and lungs, and had significantly reduced mortality (6). Another similar study showed a maximum induction of heat shock proteins in the heart and lung 6 to 24 hours after heat treatment, and a 79% survival rate at 7 days in heat treated rats, compared with a 31% survival rate in rats that were not heated. The lung tissue was examined in these rats, and showed that the heat treatment resulted in significantly less lag damage compared to the unheated rats (7).
Saunas Reduce Your Risk of Pneumonia
Regular sauna use has been shown to protect against pneumonia in a long term study of large group of middle age men in Finland. 2,210 men, ages 42-61 years, were followed up after an average of 26.6 years. They compared groups who used a sauna less than one a week, 2-3 times a week, and more than 4 times a week. After adjusting for other risk factors, the group that used a sauna 2-3 times a week was 31% less likely, and the group who used a sauna more than 4 times a week was 44% less likely to be diagnosed with pneumonia (8). When they looked at all respiratory diseases, including COPD, asthma, and pneumonia, they found that 2-3 times per week sauna use reduced the risk by 27%, and more than 4 times a week reduced the risk of respiratory disease by 41% (9). Another study found that regular sauna use reduces the risk of all cause mortality (10).
High Tech Health Far Infrared Saunas
So, in this time of social isolation and fear, consider adding a personal sauna to your home to boost your immunity, reduce your risk of all cause mortality, and to relax you and alleviate anxiety during this uncertain time!
- Thermotolerance and the heat shock proteins. Burdon RH. Symp Soc Exp Biol. 1987
- The role of heat shock proteins and their receptors in the activation of the immune system. Singh-Jasuja H, Hilf N, Arnold-Schild D, Schild H. Biol Chem. 2001 Apr;382(4):629-36
- How is the immune response affected by hyperthermia and heat shock proteins? Calderwood SK, Theriault JR, Gong J. Int J Hyperthermia. 2005 Dec;21(8):713-6
- Heat shock proteins in infection. Bolhassani A, Agi E. Clin Chim Acta. 2019 Nov;498:90-100
- Heat shock treatment decreases the mortality of sepsis in rats. Yang RC, Wang CI, Chen HW, Chou FP, Lue SI, Hwang KP. Kaohsiung J Med Sci. 1998 Nov;14(11):664-72
- Induction of the heat shock response reduces mortality rate and organ damage in a sepsis-induced acute lung injury model. Villar J, Ribeiro SP, Mullen JB, Kuliszewski M, Post M, Slutsky AS. Crit Care Med. 1994 Jun;22(6):914-21
- Frequent sauna bathing may reduce the risk of pneumonia in middle-aged Caucasian men: The KIHD prospective cohort study. Kunutsor SK, Laukkanen T, Laukkanen JA. Respir Med. 2017 Nov;132:161-163
- Sauna bathing reduces the risk of respiratory diseases: a long-term prospective cohort study. Kunutsor SK, Laukkanen T, Laukkanen JA. Eur J Epidemiol. 2017 Dec;32(12):1107-1111
- Association between sauna bathing and fatal cardiovascular and all-cause mortality events. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. JAMA Intern Med. 2015 Apr;175(4):542-8