Yasuaki Goto

Physical Activity and All-cause Mortality in Japan: The Jichi Medical School (JMS) Cohort Study

Background In April 2008, a new health check-up and health guidance system was introduced by the Japanese Government to promote increased physical activity. However, few studies have documented the health benefits of physical activity in Asian populations. We examined the association between all-cause mortality and level of physical activity in a Japanese multicommunity population-based study. Methods The Jichi Medical School Cohort Study is a multicommunity, population-based study based in 12 districts in Japan. Baseline data from 4222 men and 6609 women (mean age, 54.8 and 55.0 years, respectively) were collected between April 1992 and July 1995. The participants were followed for a mean duration of 11.9 years. To determine the association between all-cause mortality and level of physical activity, crude mortality rates per 1000 person-years and hazard ratios (HRs) with 95% confidence intervals (CI) were determined using the Cox proportional hazards model. Physical activity was categorized by using physical activity index (PAI) quartiles. The lowest (first) PAI quartile was defined as the HR reference. Results In men, the lowest mortality rate was observed in the third quartile, with 95 deaths and a crude mortality rate of 7.6; the age- and area-adjusted HR was 0.59 (95% CI, 0.45–0.76), and the mortality curve had a reverse J shape. In women, the lowest mortality rate was observed in the highest PAI quartile, with 69 deaths and a crude mortality rate of 3.5; the HR was 0.81 (95% CI, 0.58–1.12). Conclusion Our results suggest that increased physical activity lowers the risk for all-cause death in Japanese.

Incidence of Symptoms and Accidents During Baths and Showers Among the Japanese General Public

Background Bathing is a deeply ingrained custom among Japanese; however, data on the incidence rate of symptoms and accidents during bathing have not yet been reported for the Japanese general public. Methods We conducted a population-based cross-sectional study of 617 Japanese adults who attended a specialized health checkup. Participants completed a self-administered questionnaire to assess weekly frequencies of bathtub bathing and showering and the frequency of symptoms/accidents (falling, loss of consciousness, and other) during these activities in the past year. We calculated the incidence rates of accidents per 10 000 baths/showers and 95% confidence intervals (CIs) and compared the clinical characteristics of participants who had symptoms/accidents with those who did not. Results The incidence rates of accidents per 10 000 bathtub baths and showers were 0.43 (95% CI: 0.22–0.84) and 0.24 (95% CI: 0.04–1.37). Although these rates are low, there were 740 000 bathtub bathing-related accidents in Japan, due to the fact that bathing is an almost-daily habit. There was no significant difference in clinical characteristics between groups Conclusions We collected basic information on the incidence of bathing-related accidents in Japan. Falls and loss of consciousness during bathing or showering can potentially lead to a serious accident, so the general public should be educated about the possibility of such accidents during bathing.

Physical Activity and Cardiovascular Disease in Japan: The Jichi Medical School Cohort Study

Background Many studies have reported an association between physical activity and cardiovascular disease (CVD); however, the effect of physical activity remains controversial. Few such studies have been conducted in Japan. Therefore, we examined the relationship between physical activity and death from CVD using prospective data from a Japanese population. Methods From a prospective cohort study that comprised 12 490 participants, data from 9810 were analyzed. From April 1992 through July 1995, a baseline survey was conducted in 12 communities in Japan. The participants were followed up until December 2005. Physical activity was assessed using the physical activity index (PAI). PAI scores were grouped in quartiles: Q1 was the lowest PAI quartile and Q4 was the highest. Hazard ratios (HRs) for death from CVD, stroke, and myocardial infarction (MI) were calculated for all PAI quartiles. Results The mean follow-up period was 11.9 years, during which time 194 participants died of CVD. With Q1 as the reference, the HRs for death from CVD in Q2, Q3, and Q4, were 0.62 (95% confidence interval, 0.40–0.98), 0.53 (0.31–0.88), and 0.40 (0.22–0.73), respectively, in men, and 0.71 (0.38–1.32), 0.52 (0.26–1.04), and 0.48 (0.22–1.05), respectively, in women. The HRs for death from CVD subtypes were similar but not statistically significant. Conclusions Among a Japanese population, physical activity was associated with a decreased risk of death from CVD. However, more evidence is needed to elucidate the relationships between physical activity and CVD subtypes.

The Consumption of Bicarbonate-Rich Mineral Water Improves Glycemic Control

Hot spring water and natural mineral water have been therapeutically used to prevent or improve various diseases. Specifically, consumption of bicarbonate-rich mineral water (BMW) has been reported to prevent or improve type 2 diabetes (T2D) in humans. However, the molecular mechanisms of the beneficial effects behind mineral water consumption remain unclear. To elucidate the molecular level effects of BMW consumption on glycemic control, blood metabolome analysis and fecal microbiome analysis were applied to the BMW consumption test. During the study, 19 healthy volunteers drank 500 mL of commercially available tap water (TW) or BMW daily. TW consumption periods and BMW consumption periods lasted for a week each and this cycle was repeated twice. Biochemical tests indicated that serum glycoalbumin levels, one of the indexes of glycemic controls, decreased significantly after BMW consumption. Metabolome analysis of blood samples revealed that 19 metabolites including glycolysis-related metabolites and 3 amino acids were significantly different between TW and BMW consumption periods. Additionally, microbiome analysis demonstrated that composition of lean-inducible bacteria was increased after BMW consumption. Our results suggested that consumption of BMW has the possible potential to prevent and/or improve T2D through the alterations of host metabolism and gut microbiota composition.

The effects of bathing in hot springs on the absorption of green tea catechin: A pilot study

Japan is a major tea producing country, and green tea is known for its health benefits which are believed to be due to catechins. However, difficulties in maintaining an adequate amount of catechins in the blood have been reported. Another important health-promoting activity among the Japanese is bathing in hot springs. This pilot study examined whether the combined effects of green tea consumption and hot spring bathing improved absorption of green tea catechins. The study, with a comparative within-subject design involving two different intervention trials--green tea consumption with hot spring bathing and only green tea consumption--was conducted on 2 separate days. Plasma levels of catechin; (-)-epigallocatechin-3-O-gallate (EGCG) were analyzed from four volunteers. Plasma EGCG concentration was found to be higher for the combined trial of green tea consumption and hot spring bathing.

Physical and Mental Effects of Bathing: A Randomized Intervention Study.

Showering is the most common form of bathing worldwide. Whole-body immersion bathing in warm water (~40°C) is common in Japan and exerts sufficient hyperthermic action to induce vasodilatation and increase blood flow, supplying more oxygen and nutrients to the periphery. Cross-sectional studies report better subjective health status with an immersion bathing habit. This randomized controlled trial compared the effects on health of immersion bathing and shower bathing in 38 participants who received 2-week intervention of immersion bathing in warm water (40°C) for 10 min (bathing intervention) followed by 2-week shower bathing without immersion (showering intervention) or vice versa (n = 19 each group). Visual analog scale scores were significantly better for fatigue, stress, pain, and smile and tended to be better for self-reported heath and skin condition after bathing intervention than after showering intervention. The SF-8 Health Survey showed significantly better general health, mental health, role emotional, and social functioning scores. Profile of Mood State scores were lower for stress, tension-anxiety, anger-hostility, and depression-dejection. Immersion bathing, but not shower bathing, exerts hyperthermic action that induces increased blood flow and metabolic waste elimination, which may afford physical refreshment. Immersion bathing should improve both physical and emotional aspects of quality of life.

Psychophysiological effects of bathing in hot spring evaluated by EEG

Background Lots of Japanese have a habit to take bath with hot water over 40 degree centigrade almost every day. More than 3,000 areas of hot springs exist all over Japan and according to the survey of Japan travel bureau foundation, 90% of Japanese like to visit there as a recreation. It has been reported that bathing in hot water can augment blood flow and those kind of physical effects while taking bath have already proved by certaion number of researcheres. However psychopsysiological effects in terms of bathing in hot water have not seen yet. Yoshida et al have developed the HSK rhytms(FFR) in alpha waves measured by EEG could show the mood states. In this study, we investigate comfortableness when people take hot bath using this EEG method.