Many people are under stress due to the effects of the novel coronavirus infectious disease (COVID-19). According to the interim results of a nationwide mental health survey conducted by the University of Tsukuba in August 2020, around 80% of the respondents said that they felt stress, with nearly 40% mentioning high stress levels (Note 1).
While abdominal breathing, stretching, moderate exercising, and listening to music are known as relaxation techniques that are useful for successfully coping with stress, tub bathing and hot spring bathing also have the effect of mitigating the risk of contracting lifestyle diseases and the risk of being recognized as a person requiring public nursing care (which means losing the ability to perform simple tasks from everyday life; hereinafter referred to as the "functional disability risk"). In the future, it may become possible to increase exports of "unit baths" and to attract foreign tourists' attention by improving the international reach of Japan's appealing bathing culture, including both tub bathing at home—the Japanese style of bathing is distinct from the western style in that Japanese people wash themselves fully in a shower before soaking in the clean bath water—and hot spring bathing, which is available at countless spas and resorts across the nation.
This paper considers how to live a healthy life by incorporating tub bathing and hot spring bathing into everyday life and how to take advantage of the benefits of bathing to revitalize the Japanese economy in reference to the discussions at a RIETI BBL webinar titled "Modern Hot-spring Treatments and Health Tourism: Revitalization of human mind, body and regional economies with the powers of hot-springs," held on November 19, 2020 (Note 2).
Stress-Relieving Effect of Tub Bathing and Hot Spring Bathing
Bathing provides mental and physical relaxation and refreshment due to the heating effect, where blood flow improves by heating the body, the buoyancy effect, which eases joint and muscle tension, the cleansing effect, as grime and dirt are washed off the body, and you can release yourself from daily stress by bathing in a closed space. According to a survey conducted in Shizuoka Prefecture with respect to the correlation between the frequency of bathing and the level of subjective happiness, the percentage of people who felt a high level of subjective happiness was 53.9% among respondents who were taking a bath every day but was only 44.0% among those who were not—although the possibility cannot be denied that people whose mind is relatively restful may take baths more frequently in the first place (Note 3).
According to a questionnaire survey conducted under the Ministry of the Environment's National Survey Project to Measure the Effects of an "ONSEN Stay"—it should be kept in mind that this survey focused only on hot spring users—, users recognized various relieving and improving effects with respect to mental and physical conditions after taking a hot spring bath, including "eased fatigue" (83.0%), "increased feeling of happiness (82.6%), "relieved stress" (82.0%), and "led to (appeared to lead to) more sound sleep" (81.1%) (Note 4).
There is also a study which compared the effects of bathing in plain hot water and taking a hot spring bath at the same spa facility, which found that taking a hot spring bath had a higher relaxation effect than bathing in plain hot water. It is presumed that the higher relaxation effect was brought about by the comfortable feel and percutaneous absorption effect of the hot spring water, and the moisture-holding effect of minerals in the hot spring water on the skin (Note 5).
Preventive-Medicine Effect of Tub bathing and Hot Spring Bathing
Tub bathing and hot spring bathing also have the effect of mitigating the risk of contracting lifestyle diseases and the functional disability risk.
According to a study on the correlation between the frequency of bathing and the risk of ischemic heart disease (myocardial infarction and sudden cardiac death) and stroke (cerebral infarction, cerebral hemorrhage, and subarachnoid hemorrhage), both of which are related to lifestyle diseases, the risk of suffering from an ischemic heart disease for people who take a bath almost every day was 35% lower than the risk for people who took a bath twice or less a week. The risk of suffering from a stroke was 26% lower for people who took a bath almost every day. However, when analyzed by more specific type of disease, a statistically significant correlation was not observed with respect to myocardial infarction, sudden cardiac death, and subarachnoid hemorrhage (Note 6). Another study found that the functional disability risk was 30% lower for elderly people who took a bath seven times or more a week compared with those who did so twice or less a week (Note 7).
A survey conducted in Atami City, Shizuoka Prefecture on people who took the specified health checkup under the health insurance system showed that the proportion of people with high blood pressure was lower among those who routinely bathed in hot spring water distributed to their homes than among other people, suggesting that hot spring bathing has a positive effect on cholesterol levels (Note 8).
Revitalizing Japan by Promoting Tub Bathing and Hot Spring Bathing as Means of Stress Relief and Preventive Medicine
In order to make further use of tub bathing and hot spring bathing for the purposes of stress relief and preventive medicine, it is important to establish a system which encourages the practice of bathing.
As an initiative to promote health-conscious management, companies are expected to take a positive view of the benefits of tub bathing and hot spring bathing and to provide subsidies to encourage employees to use bathing and hot spring spa facilities through an evidence-based approach, taking into consideration the results of health checkups. With respect to challenges related to lifestyle diseases and habits in everyday life that may cause the diseases, the basic policies for comprehensive promotion of people's health (Healthy Japan 21 (second period): FY2013 to 2022) describes the "basic policy," "the current situation and goals," and "measures" in each of nine fields (nutrition/eating habits, physical activity and exercise, rest/mental health enhancement, tobacco, alcohol, dental health, diabetes, circulatory diseases, and cancer). If the stress-relieving and preventive-medicine effects of tub bathing and hot spring bathing are mentioned at the time of revision of the basic polices, companies will find it easier to incorporate tub bathing and hot spring bathing into health-conscious management.
Regions can make use of the benefits of bathing both for the purpose of promoting residents' health and regional revitalization. In 2011, Taketa City in Oita Prefecture established a unique hot spring therapy health system in order to conduct an initiative to advance hot spring-based preventive medicine and health enhancement and promote new tourism activities, such as long-stay tourism (Note 9). This system provides tourists who stay at an accommodation facility with hot spring access for a total of three nights or more over a six-month period, or who stay at an accommodation facility without such access but use a bathing facility on more than half the number of days of stay, with a subsidy to cover part of the expenses. In FY 2019, 625 people received the subsidy.
As for public assistance for hot spring therapy, there is a system that applies the medical expense deduction to part of the expense of hot spring therapy provided at hot spring-based health enhancement facilities recognized by the Ministry of Health, Labour and Welfare in accordance with doctors' prescriptions. However, as this system is not necessarily widely known, the number of applications for the medical expense deduction has remained limited, except from users of facilities at the Toyotomi Hot Springs (Toyotomi Town, Hokkaido Prefecture), which is popular among people seeking hot spring therapy because of the positive therapy effects regarding skin diseases. There is a demand for the establishment of a system that can be easily used in accordance with the circumstances of respective regions.
According to a survey conducted by the National Health Insurances Medical Meeting, medical costs for elderly people declined in municipalities actively implementing hot spring-based health enhancement programs and medical costs for people frequently using hot spring facilities were found to be lower (Note 10). With the increase in the social security burden, it is necessary to examine the correlation between tub and hot spring bathing and medical costs in order to realize a sustainable social security system.
To promote exports of unit baths and to improving the international reach of Japan's appealing bathing culture, including tub and hot spring bathing, it is desirable to take promotion measures in combination with activities to disseminate information on the stress-relieving and preventive-medicine effects of bathing. As mentioned in References of this paper, there is evidence available in English. While developing the preparedness for construction and maintenance work is essential for exports of unit baths, it is first and foremost important to collect and organize evidence and facilitate understanding on Japan's bathing culture, including both tub and hot spring bathing, by disseminating information in an easy-to-understand manner.
