Does the Combination of Finnish Sauna Bathing and Other Lifestyle Factors Confer Additional Health Benefits? A Review of the Evidence.

Sauna bathing, a tradition deeply rooted in the Finnish culture, has been used for thousands of years for leisure, relaxation, and wellness. Sauna bathing is linked with substantial health benefits beyond its use for leisure and relaxation. Several observational and interventional studies suggest that regular or frequent sauna bathing reduces the incidence of vascular and nonvascular diseases, such as hypertension, cardiovascular disease, dementia, and respiratory conditions; may improve the severity of conditions such as musculoskeletal disorders, COVID-19, headache, and influenza; and increases the life span. The beneficial effects of sauna bathing on adverse outcomes have been linked to its blood pressure-reducing, anti-inflammatory, antioxidant, cytoprotective, and stress-reducing properties and its synergistic effect on neuroendocrine, circulatory, cardiovascular, and immune function. Evidence suggests that frequent sauna bathing is an emerging protective risk factor that may augment the beneficial effects of other protective risk or lifestyle factors, such as physical activity and cardiorespiratory fitness, or attenuate or offset the adverse effects of other risk factors, such as high blood pressure, systemic inflammation, and low socioeconomic status. This review summarizes the available epidemiologic and interventional evidence linking the combined effects of Finnish sauna bathing and other risk factors on vascular outcomes including cardiovascular disease and intermediate cardiovascular phenotypes, nonvascular outcomes, and mortality. We also discuss the mechanistic pathways underlying the joint contributions of Finnish sauna bathing and other risk factors on health outcomes, the public health and clinical implications of the findings, gaps in the existing evidence base, and future directions.

Attenuated Risk of Pneumonia Due to Inflammation by Frequent Sauna Baths: A PROSPECTIVE COHORT STUDY.

PURPOSE: Inflammatory pathways are involved in the pathogenesis of pneumonia. Frequent sauna sessions may reduce the risk of respiratory tract infections including pneumonia independent of inflammation. We aimed to evaluate the independent and joint associations of high-sensitivity C-reactive protein (hsCRP) and frequency of sauna bathing (FSB) with risk of pneumonia in a prospective cohort study. METHODS: Serum hsCRP as an inflammatory marker was measured using an immunometric assay and FSB was assessed by self-reported sauna bathing habits at baseline in 2264 men aged 42-61 yr. Serum hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and FSB as low and high (defined as ≤1 and 2-7 sessions/wk, respectively). Multivariable-adjusted HRs (CIs) were calculated for incident pneumonia. RESULTS: A total of 528 cases of pneumonia occurred during a median follow-up of 26.6 yr. Comparing high versus normal hsCRP, the multivariable-adjusted risk for pneumonia was HR = 1.30 (95% CI, 1.04-1.62). The corresponding risk was HR = 0.79 (95% CI, 0.66-0.95) comparing high versus low FSB. Compared with men with normal hsCRP and low FSB, high hsCRP and low FSB was associated with an increased risk of pneumonia in multivariable analysis (HR = 1.67: 95% CI, 1.21-2.29), with no evidence of an association for high hsCRP and high FSB and pneumonia (HR = 0.94: 95% CI, 0.69-1.29). CONCLUSIONS: In a general middle-aged to older male Caucasian population, frequent sauna baths attenuated the increased risk of pneumonia due to inflammation.