A new observational study has found a statistically significant link between having hot baths on a regular basis and a lower risk of cardiovascular disease and events such as stroke.
Cardiovascular disease is an umbrella term referring to various conditions that affect the heart and the vascular system.
These conditions are very common among the aging population — and according to the World Health Organization (WHO), cardiovascular disease is the top cause of death at a global level.
Certain lifestyle factors can influence a person’s risk of cardiovascular problems, and a person can take steps to change them. Among these modifiable factors are levels of exercise and the diet.
Now, new research conducted by investigators from seven Japanese institutions plus Minia University, in Egypt, has found an association between regular, frequent hot bathing and a lower risk of cardiovascular disease.
While the study was observational, and thus cannot verify that any relationship is causal, the authors suggest the possibility of a credible underlying mechanism.
“Heat exposure increases core body temperature, cardiac contractility, heart rate and blood flow, and decreases vessel endothelial shear stress,” the authors note in their study paper, published in the journal Heart.
The paper’s first author is Tomohiko Ukai, from the Osaka Prefectural Institute of Public Health and Osaka University Graduate School of Medicine, in Japan.
“These effects,” the researchers explain, “are similar to the impact of exercise and are believed to improve vascular function over the long term.”
In their study, the researchers accessed data from the Japan Public Health Center-based Study Cohort I, which included over 61,000 participants aged 45–59.
Around 43,000 of these participants filled in targeted questionnaires at the start of the study, in 1990.
Through these questionnaires, they reported information not just related to their bathing practices, but also to potential confounding factors, including exercise habits, dietary habits, alcohol intake, body mass index, average sleep duration, and medical history.
The original study included follow-up information about the participants’ health, either until their death or until the