Cardiovascular disease (CVD) is a condition accounting for 30% of all cause mortality and 10% disability worldwide (Zhang & Chang, 2019). Underlying causes of CVD can include congenital abnormalities, infectious agents, nutritional, and environmental factors (Reisner & Reisner, 2017; Sears, Kerr, & Bray, 2012). As such, interventions to manage said factors are paramount in maintaining cardiovascular health and longevity. As a means of appreciating causes of CVD, the following sections will consider the influence of environmental factors to include heavy metals such as arsenic, cadmium, lead, and mercury exposure. Furthermore, sweating via sauna will be explored as a simple and cost-effective method to facilitate removal and management of the aforementioned heavy metals.
Sears et al. (2012) stated that almost every individual has had acute and/or chronic exposure to heavy metals in present day. Furthermore, almost all individuals exposed to such heavy metals have measurable levels circulating, and accumulating, within their bodies (Sears et al., 2012). Such heavy metals like arsenic, cadmium, mercury, and lead have no physiological benefit and are confirmed as carcinogens as well as drivers behind endocrine, nervous, immunological, renal, musculoskeletal, and CVD (Sears et al., 2012). Exposure to such heavy metals emanate from foods grown from soil enriched with fertilizers containing arsenic, fish consumed that contain mercury, and household items containing cadmium and lead such as batteries, electronics, pesticides, paints, and alloys (Sears et al., 2012). Essentially, such heavy metals have infiltrated the air, food, water, and environment in a ubiquitous fashion. Having briefly considered the origins and physiological consequences of heavy metals, the following will explore evidence of sauna use, as a method of detoxification, in greater detail.
Several interventions exist to include avoidance/minimization of heavy metal exposure as well as implementing nutrition, supplementation, and chelation protocols (Crinnion, 2007; Sears et al., 2012). As stated by the researchers, an often overlooked intervention is through sweating; a simple and cost-effective strategy (Crinnion, 2007; Sears et al., 2012). In addition to commonly recognized detoxifications pathways via urine and feces, sweating has also shown to contain measurable levels of nickel, aluminum, antimony, arsenic, mercury, lead, and cadmium (Sears et al., 2012; Crinnion, 2007). Thus, saunas can provide a simple and passive means to achieve body temperatures sufficient to induce sweating and release of said heavy metals. Furthermore, emerging evidence has suggested that sauna bathing is associated with improvements in insulin sensitivity, endothelial function, arterial stiffness, blood pressure, systemic inflammation, and markers of oxidative stress; such favorable changes, by consequence, helps reduce risk of cardiovascular disease and all-cause mortality (Hussain, & Cohen, 2018; Kunutsor et al., 2018).
Sauna protocols explored by researchers by Hussain and Cohen (2018) included dry saunas, steam saunas, and infrared saunas. Furthermore, the systematic review yielded 40 studies that satisfied inclusion criteria. Such studies covered sauna temperatures ranging from 50 degrees °C to 90 degrees °C with relative humidity ranging from 10% to 30%, durations lasting from 5 minutes to 30 minutes per session, with a frequency ranging from one to multiple sauna sessions per week (Hussain & Cohen, 2018). Despite the lack of homogeneity between said protocols, improvements in biomarkers listed from the last section improved (Hussain & Cohen, 2018). Of particular note and interest, were the two observational studies from the research of Hussain et al. (2018); the data indicated that heat stress, either from infrared or Finnish-style sauna, both caused significant sweating likely inducing favorable metabolic, hormetic, and cardiovascular adaptations. Finally, Hussain & Cohen (2018) noted said observational studies found significant risk reductions in dementia, Alzheimer’s disease, and sudden cardiac death in males who used a sauna 4−7 times per week rather than once per week. Such observational data might suggest that increased frequency per week will yield greater physiological benefit to individuals than singular weekly exposures.
Environmental exposure to toxins such as arsenic, cadmium, lead, and mercury are nearly unavoidable. Multiple protocols are available to induce excretion and manage said heavy metals via avoidance/minimization of exposure as well as implementing nutrition, supplementation, and chelation protocols (Crinnion, 2007; Sears et al., 2012). Evidence has suggested that sauna interventions have also risen as a viable, simple, and effective means of removing toxic burdens, sometimes exceeding that of renal pathways (Sears et al., 2012). As such, sauna protocols might act as an adjunct tool in a wider, more inclusive, program of detoxification.
References
Crinnion, W. (2007). Components of practical detox programs: Sauna as a therapeutic tool. Alternative Therapies in Health and Medicine, 13(2), S154-S156.
Hussain, J., & Cohen, M. (2018) Clinical effects of regular dry sauna bathing: A systematic review. Evidence-Based Complementary and Alternative Medicine, 1-30. doi: 10.1155/2018/1857413
Kunutsor, S. K., Hakkinen, A., Zaccardi, F., Laukkanen, T., Lee, E., Willeit, P., … Laukkanen, F. (2018). Short-term effects of Finnish sauna bathing on blood-based markers of cardiovascular function in non-naive users. Heart and Vessels, 33(12), 1516-1524.
Reisner, E. G., & Reisner, H. M. (2017). An introduction to human disease: Pathology and pathophysiology correlations (10thed.). Burlington, MA: Jones & Bartlett Learning.
Sears, M. E., Kerr, K. J., & Bray, R. I. (2012). Arsenic, cadmium, and mercury in sweat; A systematic review. Journal of Environmental and Public Health. doi:10.1155/2012/184745
Zhang, H., & Chang, R. (2019). Effects of exercise after percutaneous coronary intervention on cardiac function and cardiovascular adverse events in patients with coronary heart disease: Systematic review and meta-analysis. Journal of Sports Science and Medicine, 18(2), 213-222.
-Michael McIsaac