The direction of future research
The research done so far and the work of summarising them for dissemination is invaluable. Much research is from countries like Finland, where sauna practice is a usual and a protected part of everyday life for all. It will be interesting for more research to happen in the UK and how sauna impacts peoples lives here. We are also looking forward to more large cohort studies in the future and stringent systematic reviews.
The Sauna Research Institute was established in 2020 with the goal to study the effects of thermal exposure, and produce peer reviewed research for publication with conclusions of how different protocols and practices can affect physical and mental health and wellbeing of humans. The research catalogue for the Sauna Research Institute is a useful reference for sauna research.
Evidence on physical health benefits
Tanjaniina Laukkanen, a researcher from the University of East Finland with colleagues Hassan Khna, Francesco Zaccardi and Jari Laukkanen published an important paper on the benefits of regular sauna for heart health (Laukkanen et al. 2018). This study was conducted with a prospective cohort of 2315 middle-aged people from Eastern Finland (age range, 42-60 years). They concluded that “increased frequency of sauna bathing is associated with a reduced risk of sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease, and all-cause mortality. Further studies are warranted to establish the potential mechanism that links sauna bathing and cardiovascular health”.
A recent summary by Patrick and Johnson, (2021) reported on studies looking at sauna bathing and physiological response to heat stress, protection against cardiovascular disease, beta-endorphins and the opioid system, the endocrine system, immune function and respiratory infection, physical fitness, promotion of cardiovascular health, cognitive and mental health and indicators for sauna bathing concerns. Patrick and Johnson concluded that “sauna bathing is associated with many health benefits, from cardiovascular and cognitive health to physical fitness and muscle maintenance. It is generally considered safe for healthy adults and may be safe for special populations with appropriate medical supervision”.
Evidence on Mental Health Benefits
Liv Orlando, Mental Health Officer for the British Sauna Society provides a brief summary of studies showing the benefits of sauna for mental health. One study stands out as reporting that using a sauna once a day for four weeks has been shown to reduce symptoms of depression, including better appetite and reduced anxiety (Masuda 2005).
What sauna users say themselves
The Global Sauna Survey (Hussain, Greaves & Cohen 2019) conducted an online survey between October 2016 and October 2017. “Of 572 logins recorded, 482 valid responses were generated. Both men (51.3%) and women (48.7%) were represented, and respondents were predominantly well-educated (81.8%), non-smoking (90.6%), regularly-exercising (78.8%) individuals of normal-to-overweight status (87.1%) who sauna-bathed approximately 1–2 times per week.” The main reasons people gave for using the sauna included relaxation and stress reduction, pain relief and socializing. The study highlights reported:
- “This is the first study to investigate the health habits of the global sauna community.
- Relaxation/stress reduction was the most cited motivation to use a sauna.
- Most sauna bathers cited improvements in sleep lasting 1–2 nights after using a sauna.
- Sauna users 5–15 times monthly had comparatively higher mental well-being scores.
- Most adverse reactions to sauna bathing were mild reports of dizziness and dehydration.
- Many report sauna bathing to ‘detox’, not yet well-understood by the research community.
- Few report sauna bathing for cardiovascular benefits, which is supported by research.
- Further studies and greater education around sauna as a wellness intervention are needed”.