Many health benefits are claimed by people and establishments promoting sauna baths; however, the medical evidence to support these claims is not well established. This article aims to systematically review recent research on the effects of repeated dry best infrared sauna procedures on human health. A systematic search was performed of medical databases for studies reporting the health effects of regular dry sauna baths on humans from 2000 inwards. Risk of bias was assessed according to the Cochran Collaboration guidelines . Forty clinical studies involving a total of 3855 participants met the inclusion criteria. Only 13 studies were randomized controlled trials and most studies were small (n <40).
The reported outcome measures were heterogeneous, with most studies reporting beneficial health effects. Only one person sauna small study (n = 10) reported an adverse health effect from disruption of male parthenogenesis, which was shown to be reversible upon cessation of sauna activity. A growing body of evidence suggests that regular sauna baths can lessen and prevent the risk of acute and chronic illnesses. Over the past decade, a considerable amount of research data from various countries on the potential health benefits of sauna baths as well as the putative biological pathways underlying these effects have been reported. Given the mixed evidence in the literature, there is a need to pool the data to allow for proper interpretation. This review summarizes the available epidemiological, experimental and intervention evidence linking sauna baths, cardiovascular outcomes, and other health benefits;
the postulated
biological mechanisms underlying these associations; areas of exceptional
uncertainty; and implications for clinical practice. Since there are different
forms of passive heat therapy (e.g. repeated hot water immersion, infrared
sauna, Wain therapy, and Turkish bath), this review focuses only on the
evidence of traditional Finnish saunas, as they are the most studied to date. .
We searched for observational studies (prospective cohort, nested or
case-control, retrospective cohort), randomized controlled trials (RCTs) and
non-RCTs of MEDLINE and EM BASE from inception until February 24, 2018, in with
particular emphasis on Finnish cheap sauna baths. Search terms included sauna bath,
Finnish, cardiovascular disease, coronary artery disease, sudden cardiac death,
heart failure, hypertension, blood pressure, dementia, depression, lung
disease, mortality, lipids, naturalistic peptides, hormones, endothelial
function , inflammation, oxidative stress, arterial stiffness, arterial
compliance and minimal media thickness. Studies were limited to those conducted
in adult humans and written in English. A regular dry sauna bath has potential
health benefits. More and better data are needed on the frequency and extent of
adverse side effects. Further study is also needed to determine the optimal
frequency and duration of different types of sauna baths for targeted health
effects and the specific clinical populations that are most likely to benefit
from them.