Does the bathing style of Japanese contribute to prevent atherosclerotic diseases?

Purpose; Japanese generally bath in bathtub with hot water (104-108°F) mostly every day, which is a specific daily habit being different from other countries. We investigate the relationship between the bathing habit of people who have annual health check-up in our institute and atherosclerosis related factors to evaluate the positive effects of bathing in hot water. Methods; The questionnaire survey was conducted on 169 participants (mean age, 46.9 years; 100 men and 69 women) in February 2011. The questionnaire items were the favorite style of bathing (bathing in bathtub or taking shower), the frequency of bathing per week, the bathing time of the day, and the favorite temperature of bathing water. Atherosclerotic related factors from routine physical examinations and laboratory data were collected. To examine the relationship between a bathing style and atherosclerotic risk factors, participants were classified as people who bath in bath tub every day and the others. Analysis of variance was used and a P-value of ≺0.05 was considered statistically significant. Results: Overall, 159 participants (94.1%) answered that they like to take bath in bathtub very much or moderately. The favorite temperature of bathing water was 104°F in winter and even in summer. Participants especially bathing in bathtub every day showed lower systolic and diastolic blood pressure, fasting plasma glucose, triglyceride, waist circumference, AST, ALT, and higher Adiponectine compared with other participants. Conclusion; Bathing with hot water every day may have good effects to prevent hypertension, diabetes mellitus, and metabolic syndrome. We think that Japanese bathing style could contribute to prevent atherosclerotic diseases due to Japanese longevity.