HEALTH BENEFITS

The Psychological and Physiological Health Benefits of Regular Dry Sauna Use

Abstract

Regular dry sauna use, particularly at high frequencies of four to seven times per week, has been associated with numerous physiological and psychological health benefits. This literature review examines findings from seven studies, including both prospective cohort studies and review articles, primarily conducted in Finnish populations. The reviewed research highlights significant associations between sauna use and reduced cardiovascular disease risk, improvements in thermoregulatory responses, and potential protective effects against psychotic disorders. Various physiological changes, including alterations in prooxidative/antioxidative balance, nitric oxide production, and hemodynamic responses, have also been documented. Despite these promising findings, most studies included in this review were observational, limiting causal interpretations. Further research, particularly randomized controlled trials, is needed to establish definitive mechanisms and optimal sauna protocols for maximizing health benefits.

Introduction

Sauna bathing has long been recognized as a practice with potential health benefits, particularly in Finland, where it is deeply embedded in the culture. The increasing interest in sauna use for therapeutic purposes has prompted scientific investigations into its physiological and psychological effects. Several studies have examined the impacts of frequent dry sauna use, assessing its influence on cardiovascular function, thermoregulatory responses, and mental health. This literature review synthesizes findings from key studies to provide a comprehensive overview of the health benefits associated with sauna bathing.

Physiological Effects of Sauna Use

Among the most well-documented benefits of regular sauna use is its positive effect on cardiovascular health. Multiple cohort studies have reported an inverse relationship between sauna frequency and cardiovascular disease risk. For instance, a study by Laukkanen et al. (2014) followed 2,323 middle-aged men and found that those who engaged in sauna bathing four to seven times per week had significantly lower rates of sudden cardiac death, fatal coronary heart disease, and cardiovascular disease events compared to those who used a sauna only once per week. These findings suggest that the cardiovascular adaptations induced by repeated heat exposure may provide long-term protective effects against cardiovascular morbidity and mortality.

One of the proposed mechanisms underlying these cardiovascular benefits is the effect of sauna use on hemodynamic parameters. Acute post-sauna reductions in blood pressure have been observed, alongside longer-term decreases in resting blood pressure among habitual users. Additionally, an increase in nitric oxide metabolites has been noted following sauna sessions, indicating improved endothelial function (Gryka et al., 2020). These changes may contribute to enhanced vascular health and overall cardiovascular resilience.

Thermoregulatory adaptations have also been documented in response to regular sauna use. Acute exposure results in a rapid increase in core body temperature, which elicits sweating and subsequent evaporative cooling. Over time, individuals who use saunas frequently exhibit lower resting body temperatures, suggesting improved thermoregulatory efficiency. Furthermore, oxidative stress markers, such as total antioxidative status, have been shown to improve with regular sauna exposure, potentially enhancing cellular resilience against oxidative damage (Spears, 1969).

Psychological Benefits of Sauna Use

In addition to physiological adaptations, sauna use has been associated with mental health benefits. Two large-scale cohort studies by Laukkanen et al. (2018a, 2018b) investigated the relationship between sauna bathing and psychotic disorders. These studies found that men who used saunas four to seven times per week had a 78% lower risk of developing psychosis compared to those who engaged in sauna use once per week. The mechanisms underlying this association remain speculative but may involve the effects of heat exposure on neuroendocrine function, stress reduction, and improved sleep quality.

Although direct assessments of stress and relaxation effects were not prominent in the included studies, review articles by Brooks (2019) and Nath (2023) highlighted the potential of sauna bathing to enhance mental well-being. The relaxation induced by sauna sessions, combined with the physiological effects of heat exposure, may contribute to reduced stress levels, improved mood, and overall psychological resilience. However, these claims require further substantiation through experimental research.

Frequency-Dependent Health Benefits

The degree of health benefits derived from sauna use appears to be frequency-dependent. Studies have consistently reported more pronounced cardiovascular and psychological advantages among individuals who use saunas multiple times per week. For instance, Laukkanen et al. (2014) found that those who used saunas two to three times per week exhibited a moderate reduction in cardiovascular risk, whereas those who used saunas four to seven times per week experienced a more substantial risk reduction. Similarly, studies on physiological parameters, such as resting pulse rate and oxidative stress markers, have reported greater improvements with higher sauna frequencies (Gryka et al., 2020).

A study by Spears (1969) examined the physiological effects of sauna use in college women and found that those who engaged in three sauna sessions per week exhibited greater reductions in resting pulse rate, blood pressure, and body temperature compared to those who participated only twice per week. Another study by Gryka et al. (2020) assessed the impact of ten sauna sessions over three weeks and found improvements in oxidative balance and nitric oxide production, further supporting the notion that higher sauna exposure yields greater health benefits.

Limitations and Future Directions

Despite the promising findings highlighted in this review, several limitations should be acknowledged. The majority of the studies included were observational, making it difficult to establish causality. Additionally, most research was conducted in Finnish populations, which raises questions about the generalizability of the findings to other ethnic groups and climates. Sample sizes varied considerably, with some studies including thousands of participants, while others relied on much smaller cohorts. Furthermore, inconsistencies in sauna protocols and outcome measures across studies limit the ability to draw definitive conclusions about optimal sauna use parameters.

Future research should focus on conducting randomized controlled trials to establish causal relationships between sauna use and health outcomes. Studies investigating the effects of sauna use in diverse populations, as well as exploring underlying biological mechanisms, would also be valuable. Moreover, standardized sauna protocols should be developed to enhance comparability between studies and provide clearer recommendations for public health guidelines.

Conclusion

Regular dry sauna use has been associated with numerous physiological and psychological health benefits. The strongest evidence supports its role in reducing cardiovascular disease risk, improving vascular function, and enhancing thermoregulatory efficiency. Additionally, preliminary findings suggest that frequent sauna use may offer protective effects against psychotic disorders and contribute to overall mental well-being. While the evidence to date is compelling, further research is required to establish causality, optimize sauna protocols, and determine the broader applicability of these findings to different populations. In light of the potential health advantages, sauna bathing may serve as a valuable adjunct to traditional health interventions aimed at promoting cardiovascular and psychological well-being.

References

Brooks, J. (2019) 'The role of sauna bathing in mental well-being', Journal of Health Studies, 12(3), pp. 45-58.

Gryka, R.J., Pilch, W. and Szulińska, M. (2020) 'Oxidative balance and nitric oxide production after sauna bathing', Journal of Thermal Biology, 89, pp. 102523.

Laukkanen, T., Khan, H. and Zaccardi, F. (2014) 'Sauna bathing and cardiovascular risk reduction: a prospective cohort study', JAMA Internal Medicine, 174(4), pp. 540-548.

Laukkanen, T. et al. (2018a) 'Frequent sauna bathing and risk of psychotic disorders', Schizophrenia Bulletin, 44(4), pp. 950-957.

Laukkanen, T. et al. (2018b) 'Sauna use and mental health outcomes in middle-aged men', Psychosomatic Medicine, 80(3), pp. 265-272.

Nath, R. (2023) 'Sauna therapy for stress reduction', Complementary Medicine Journal, 14(2), pp. 88-101.

Spears, I. (1969) 'Physiological responses to sauna bathing in college women', Journal of Applied Physiology, 27(5), pp. 713-718.