Too many studies to list. I pulled some data from the following Review:
Evid Based Complement Alternat Med. 2018; 2018: 1857413.
Published online 2018 Apr 24. doi:
10.1155/2018/1857413
PMCID: PMC5941775
PMID:
29849692
Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review
Joy Hussain and
Marc Cohen
Many health benefits are claimed by individuals and facilities promoting sauna bathing; however the medical evidence to support these claims is not well established. This paper aims to systematically review recent research on the effects of repeated ...
www.ncbi.nlm.nih.gov
Cardiovascular:
Positive,
BP and CTR decreased in both groups (sauna
p < 0.01,
p < 0.001;
control
p < 0.05,
p < 0.05).
Body wt decreased
(
p < 0.0001); LVEF on ECHO increased (
p < 0.0001); plasma BNP decreased (
p < 0.001) in sauna group compared with control group
Positive,
fewer PVCs (
p < 0.01), fewer couplets (
p < 0.05), fewer episodes of VT (
p < 0.01), decreased CTR (
p < 0.05), increased HRV variability (
p < 0.01), lowered serum levels of BNP (
p < 0.01) in sauna treatment group compared to control group
Positive,
systolic BP (
p < 0.05) and urinary 8-epi- prostaglandin F2
α levels (
p < 0.001) significantly lower in sauna group compared to control group
Positive,
increased LVEF (left ventricular ejection fraction),
p = 0.023; reduced levels of norepinephrine and BNP,
p = 0.015 and
p = 0.035;
Positive,
decreased body wt (
p < 0.05), SBP and DBP (
p < 0.01,
p < 0.05)
Positive, reduced total cholesterol (
p < 0.05), reduced LDL cholesterol (
p value unclear), increased HDL cholesterol (
p < 0.05)
Positive, reduced total cholesterol (4.50 ± 0.66 mmol/L to 4.18 ± 0.41 mmol/L,
p = 0.02) and LDL levels (2.71 ± 0.47 mmol/L to 2.43 ± 0.35,
p = 0.01) after 10 sessions of sauna over 2 weeks – returned to baseline after 2 weeks without sauna
Positive, reduction in total cholesterol (4.47 ± 0.85 mmol/L to 4.25 ± 0.93 mmol/L,
p < 0.05) and LDL levels (2.83 ± 0.80 mmol/L to 2.69 ± 0.83 mmol/L,
p < 0.05) after repeated sauna
NEURO:
Positive,
sauna bathing 4−7 times a week associated with 66% risk reduction (hazard ratio 0.34, 95% CI) in developing dementia or Alzheimer's compared with 1 time/week
Positive,
sauna bathing 4–7 sessions weekly associated with 40% reduction in all-cause mortality compared with 1 session weekly, (hazard ratio 0.60, 95% CI, 0.46–0.80,
p < 0.001)
Positive,
improved stress (
p = 0.042), fatigue (
p = 0.014), general health (
p = 0.037) on SF-36
Sauna studies of rheumatological disease/chronic pain/depression.
In addition to having profound physiological effects, sauna bathing is reported to have beneficial psychological effects that are reflected in the many reports of improved well-being, pain tolerance, and other self-assessed symptom-related scoring [
34,
36,
43,
45,
46,
50–
56,
58,
60,
68,
69]. The psychological impact of sauna bathing may be due to a combination of factors that include release of endorphins and other opioid-like peptides such as dynorphins [
81,
92], forced mindfulness, psychological stress reduction, relaxation, improved sleep, time out from busy life schedules, placebo effects, and other aspects of individual psychological and social interactions that likely occur around frequent sauna activity.
Positive,
44% reduction in HA intensity in 6 weeks of treatment arm.
Positive,
increased likelihood of return to work 2 years later (
p < 0.05); decrease in anger scoring in sauna group compared to control (4.5 ± 1.1 to 2.2 ± 1.6,
p < 0.001)
Positive, improved somatic complaints (
p < 0.001), improved hunger scores (
p < 0.0001), and improved relaxation scores (
p < 0.0001) in sauna group compared to control group. Plasma ghrelin concentrations and daily caloric intake increased in sauna group
Positive,
pain and stiffness decreased in RA (
p < 0.05) and AS (
p < 0.001) groups during sauna sessions only.
Positive, decreased fatigue (
p = 0.002), improved POMS scores for anxiety (
p = 0.008), depression (
p = 0.018), fatigue (
p = 0.005)
Positive, reduced VAS pain scores (
p < 0.001); fewer # of tender pts (
p < 0.01); reduced symptoms based upon FIQ (
p < 0.001); improved quality of life on SF-36 questionnaire (
p < 0.01–0.05)
REPRO:
NEGATIVE -
Post-intervention: lowered sperm count (93 ± 27.0 × 106 vs 223 ± 52.8 × 106,
p < 0.001); lowered sperm concentration (31 ± 13.1 × 106/ml vs 89 ± 29.3 × 106/ml,
p < 0.001); fewer motile sperm