Frequent sauna bathing associated with lower cardiovascular and all-cause mortality in Finnish men
| Citation | Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Internal Medicine. 2015;175(4):542–548. |
|---|---|
| Study type | Observational study |
| Population | Middle-aged Finnish men (42–60 at enrollment), followed ~20 years |
| Sample | 2,315 participants |
| Primary source | https://doi.org/10.1001/jamainternmed.2014.8187 |
Headline finding
Compared with one sauna session per week, 4–7 sessions per week were associated with roughly 50% lower risk of fatal cardiovascular events and ~40% lower all-cause mortality over ~20 years of follow-up, with a dose-response pattern for both frequency and session length.
Limitations
- Observational cohort — sauna frequency may proxy for relaxation, socioeconomics, and lifestyle factors that adjustment cannot fully remove.
- All-male, single-country cohort within a strong sauna culture; generalizability is uncertain.
- Traditional hot-air sauna only; findings do not directly apply to infrared cabins or sauna blankets.
Why this evidence label
Large, long, well-conducted cohort with dose-response — strong observational evidence, but not causal proof.
Editorial note
The headline study behind most sauna-longevity content. The dose-response relationship and long follow-up make it unusually solid for observational work — and it is still observational, a distinction most articles citing it skip.
Why we cite it: it anchors our sauna and heat guide and the evidence labels on our heat & recovery product pages.
Reviewed by Sonic Vitality Editorial on July 12, 2026 . See our methodology and corrections policy.