As you may know, Japan has a long-standing bathing tradition, probably best exemplified by the beautiful outdoor and indoor hot spring bathing houses called onsen. In fact, the oldest onsen in Japan, the Dogo Onsen on the island of Shikoku has a 3,000-year-long history, so it’s hardly speculative to assume that fondness of baths is a part of the Japanese mentality.
This bathing culture in Japan doesn’t end at the spa either, as nearly every home in the country is equipped with a bathtub, and most Japanese people (over 80% of the population) take baths instead of a shower. But the tradition of bathing wasn’t the actual reason the study was conducted, the researchers’ reasoning was more practical and serious. The study was part of a countrywide investigation of bath fatalities since Japan’s ministry of health observed that approximately 14,000 people die while taking a bath in Japan every year, which is nearly triple the number of car crash fatalities.
One of the hypotheses that may have accounted for these unexpected deaths is a sudden cardiac arrest brought about by submerging yourself in hot water, as some researchers suggested, and the massive longitudinal study we mentioned earlier was conducted to investigate this very possibility. Unexpectedly, the researchers found quite the opposite - instead of having an adverse effect on cardiovascular and heart health, they observed that “a daily hot bath was associated with a lower overall risk of cardiovascular disease by about 28%, and a 26% lower overall risk of stroke."
We explain the study in detail in the following section. As for the high fatality rates associated with bath time in Japan, a different study actually showed that other factors, such as drowning, drinking alcohol and slipping while in the bath were responsible for the unsettling statistics.
How Can Baths Benefit Your Heart and Cardiovascular Health?
As mentioned earlier, the study in question is quite large, observing over 30,000 people over the course of 20 years. The age range of the participants when they were enrolled in the study was 40-59 years. The study was published in the journal Heart, a high profile international peer-reviewed medical journal.
All the participants were divided into three groups - those who took baths daily, those that did so 3-4 times a week, and those who took a bath less than twice a week. Throughout the observation period, the researchers have observed 2,097 occurrences of cardiovascular disease among the participants, among which were 53 sudden heart-related deaths and 1,769 strokes.
When all confounding factors were controlled for, the statistical analysis revealed a 28% decreased risk of cardiovascular issues and a 26% lower risk of a heart event in daily bathers compared to those who took baths less frequently. Another factor further decreased one’s risk of cardiovascular issues - water temperature. It has been observed that hot water further reduced the risk of cardiovascular issues to 35%, as opposed to 26% in warm water bathers.
Disclaimer: make sure the water temperature doesn’t exceed 102° F (39°C). Water too hot can make you dizzy, increasing the likelihood of falls, cause burns and have other negative effects on your health.
The reason why hot baths seem to be more beneficial than warm ones has everything to do with blood circulation - hot water is better at boosting blood flow, and it has benefits similar to exercise in improving the blood supply to your tissues and organs. Similarly, daily baths in hot water also seem to be better at reducing blood pressure, resembling the positive blood pressure effects of exercise.
Other positive health benefits of baths include reduced inflammation, better metabolism, stress, and pain reduction, as well as improved sleep and decreased anxiety levels. So we say ditch the shower and have a good relaxing bath as often as you can!