Effect of laughter yoga on salivary cortisol and dehydroepiandrosterone among healthy university students: A randomized controlled trial.

OBJECTIVE: To examine whether laughter yoga (LY), i.e., simulated laughter, alters cortisol and dehydroepiandrosterone (DHEA) levels and cortisol/DHEA (C/D) ratios. METHODS: In a randomized controlled trial, 120 healthy university students were allocated to experiencing LY, watching a comedy movie (spontaneous laughter), or reading a book. Salivary cortisol and DHEA levels were measured immediately before, immediately after, and 30 min after the intervention. RESULTS: Cortisol levels and C/D ratios significantly decreased by time in the LY and comedy movie groups. Significant group*time interactions were found between these two groups for cortisol levels and C/D ratios. DHEA levels did not change by time in the LY group. CONCLUSIONS: LY decreased cortisol levels and C/D ratios but did not affect DHEA levels. Simulated and spontaneous laughter differently affected the dynamics of cortisol levels and C/D ratios. Effect of spontaneous laughter on the cortisol dynamics lasted longer than that of simulated laughter. (UMIN000019409).

Relationship between serum isoflavone levels and disability-free survival among community-dwelling elderly individuals: nested case-control study of the Tsurugaya project.

BACKGROUND: The longer healthy life expectancy observed in Japan may be partly attributed to the Japanese diet. The researchers sought to examine whether serum isoflavone levels are associated with disability and death. METHODS: The researchers used a nested case-control study to compare serum isoflavones (daidzein, genistein, glycitein, and equol) levels between 165 participants that died or were certificated as disabled (cases) and 177 controls. Disability was defined by certification of long-term care insurance. Conditional logistic regression models were used to calculate the risk of isoflavones for the composite outcome. RESULTS: The proportion of cases was lower in the group with the highest levels of equol (34/91, 37%) compared with equol nonproducers (84/161, 52%). The risk of disability or death among equol producers remained reduced after adjusting for age and sex (odds ratio: 0.55, 95% confidence interval: 0.33-0.93). In a multivariate model, this risk was also unchanged (odds ratio: 0.51, 95% confidence interval: 0.27-0.96). There were no significant associations between daidzein, genistein, and glycitein with the composite endpoint. CONCLUSIONS: Higher serum equol levels, but not any other isoflavones, were inversely associated with the composite endpoint of disability and death. Although it cannot be concluded that equol per se has preventive effects on disability or death, higher equol levels appear associated with better health.

C-reactive protein (CRP) is a predictor of high medical-care expenditures in a community-based elderly population aged 70 years and over: the Tsurugaya project.

Because CRP is a strong independent predictor of various diseases, it was hypothesized that CRP may be a useful predictor or treatment target for medical-care expenditures. The aim of this study was to investigate the relationship between CRP and medical-care expenditures in a community-dwelling elderly population. This prospective cohort study was conducted including 925 Japanese subjects aged ≥70 years. A high-sensitivity CRP assay was used by applying the nephelometric method. Hospitalizations, outpatient visits, and expenditures were ascertained through computerized linkage with claims lodged between August 2002 and March 2008 with the Miyagi National Health Insurance (NHI) Association. Since medical-care expenditures were not normally distributed, the category of high medical-care expenditures (>75th percentile of medical-care expenditures: inpatient expenditures >$494/month; outpatient expenditure >$522/month; total expenditures >$1103/month) was used to examine the relation of CRP levels with medical-care expenditures. Multiple logistic regression analysis was used to examine the relationship between CRP cutoff points (low concentrations: <1.0mg/L; intermediate concentrations: 1.0-3.0mg/L; or high concentrations: ≥3.0 mg/L) and medical-care expenditures during 6 year-follow up period. After adjustment for potential confounding factors, a positive association of CRP with hospitalization, and total expenditures (p for trend=0.03 and 0.02, respectively) was found. An elevated baseline CRP level is an independent predictor of increases in prospective medical-care expenditures among community-dwelling elderly. Further study is required to clarify whether reducing CRP by intervention is a cost-effective measure.

Green tea consumption and the risk of incident functional disability in elderly Japanese: the Ohsaki Cohort 2006 Study.

BACKGROUND: Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly. OBJECTIVE: The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals. DESIGN: We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability. RESULTS: The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1-2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3-4 cups/d, and 0.67 (0.57, 0.79) for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d (P-trend < 0.001). CONCLUSION: Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors.

Coffee consumption and mortality due to all causes, cardiovascular disease, and cancer in Japanese women.

Coffee contains various compounds that have recently been reported to exert beneficial health effects. However, the conclusion of its relation with mortality has not yet been reached. In this study, we aimed to investigate the associations between coffee consumption and all-cause and cause-specific mortality in Japan. We included 37,742 participants (18,287 men and 19,455 women) aged 40-64 y without a history of cancer, myocardial infarction, or stroke at baseline in our analysis, based on the Miyagi Cohort Study initiated in 1990. The outcomes were mortality due to all causes, cardiovascular disease (CVD), and cancer. During the 10.3 y of follow-up, 2454 participants died, including 426 due to CVD and 724 due to cancer. In women, the multivariate hazard ratios (HR) (95% CI) for all-cause mortality in participants who drank coffee never, occasionally, 1-2 cups (150-300 mL)/d, and > or =3 cups/d were 1.00, 0.88 (0.73-1.06), 0.82 (0.66-1.02), and 0.75 (0.53-1.05), respectively (P-trend = 0.04). For CVD mortality in women, the multivariate HR (95% CI) were 1.00, 0.56 (0.36-0.86), 0.48 (0.29-0.80), and 0.45 (0.20-1.03), respectively (P-trend = 0.006). Of the specific CVD diseases, there was a strong inverse association between coffee consumption and mortality due to coronary heart disease (CHD) in women (P-trend = 0.02) but not in men. Death due to cancer was not associated with coffee consumption in either men or women, except for colorectal cancer in women. Our results suggest that coffee may have favorable effects on morality due to all causes and to CVD, especially CHD, in women.

Green tea consumption is associated with lower psychological distress in a general population: the Ohsaki Cohort 2006 Study.

BACKGROUND: Although green tea or its constituents might reduce psychological stress, the relation between green tea consumption and psychological distress has not been investigated in a large-scale study. OBJECTIVE: Our aim was to clarify whether green tea consumption is associated with lower psychological distress. DESIGN: We analyzed cross-sectional data for 42,093 Japanese individuals aged > or =40 y from the general population. Information on daily green tea consumption, psychological distress as assessed by the Kessler 6-item psychological distress scale, and other lifestyle factors was collected by using a questionnaire. We used multiple logistic regression analyses adjusted for age, sex, history of disease, body mass index, cigarette smoking, alcohol consumption, time spent walking, dietary factors, social support, and participation in community activities to investigate the relation between green tea consumption and psychological distress. RESULTS: We classified 2774 (6.6%) of the respondents as having psychological distress (Kessler 6-item psychological distress scale > or =13/24). There was an inverse association between green tea consumption and psychological distress in a model adjusted for age and sex. Although the relation was largely attenuated when possible confounding factors were adjusted for, a statistically significant inverse association remained. The odds ratio (with 95% CI) of developing psychological distress among respondents who consumed >/=5 cups of green tea/d was 0.80 (0.70, 0.91) compared with those who consumed <1 cup/d. These relations persisted when respondents were stratified by social support subgroups or by activities in communities. CONCLUSION: Green tea consumption was inversely associated with psychological distress even after adjustment for possible confounding factors.

Green tea consumption and the risk of liver cancer in Japan: the Ohsaki Cohort study.

OBJECTIVES: To investigate the association between green tea consumption and liver cancer incidence. METHODS: We prospectively followed 41,761 Japanese adults aged 40-79 years, without a history of cancer at the baseline or any missing data for green tea consumption frequency. Cox proportional hazards models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, alcohol drinking, smoking, the consumption of coffee, vegetables, dairy products, fruit, fish, and soybean. RESULTS: Over 9 years of follow-up, among 325,947 accrued person-years, the total incidence of liver cancer was 247 cases. We found that green tea consumption was inversely associated with the incidence of liver cancer. In men, the multivariate-adjusted HRs (95% CIs) for liver cancer incidence with different green tea consumption categories were 1.00 (reference) for <1 cup/day, 0.83 (0.53-1.30) for 1-2 cups/day, 1.11 (0.73-1.68) for 3-4 cups/day, and 0.63 (0.41-0.98) for >/=5 cups/day (p for trend = 0.11). The corresponding data among women were 1.00 (reference), 0.68 (0.35-1.31), 0.79 (0.44-1.44), 0.50 (0.27-0.90) (p for trend = 0.04). CONCLUSIONS: Green tea consumption is associated with a reduced risk of liver cancer incidence.

Green tea consumption and hematologic malignancies in Japan: the Ohsaki study.

Several biologic studies have reported that green tea constituents have antitumor effects on hematologic malignancies. However, the effects in humans are uncertain. The authors used data from the Ohsaki National Health Insurance Cohort Study in Japan to evaluate the association between green tea consumption and the risk of hematologic malignancies. Study participants were 41,761 Japanese adults aged 40-79 years without a history of cancer at baseline who answered a food frequency questionnaire survey in 1994. During 9 years of follow-up beginning in 1995, the authors documented 157 hematologic malignancies, including 119 cases of lymphoid neoplasms and 36 cases of myeloid neoplasms. Hazard ratios were calculated by using the Cox proportional hazards regression model. Risk of hematologic malignancies was inversely associated with green tea consumption. The multivariate-adjusted hazard ratio of hematologic malignancies for 5 cups/day or more compared with less than 1 cup/day of green tea was 0.58 (95% confidence interval: 0.37, 0.89). The corresponding risk estimate was 0.52 (95% confidence interval: 0.31, 0.87) for lymphoid neoplasms and 0.76 (95% confidence interval: 0.32, 1.78) for myeloid neoplasms. This inverse association was consistent across sex and body mass index strata. In conclusion, green tea consumption was associated with a lower risk of hematologic malignancies.

Green tea and death from pneumonia in Japan: the Ohsaki cohort study.

BACKGROUND: Experimental and animal studies have shown the activities of catechins, the main constituents of green tea, against infectious agents. No data are available on the association between green tea consumption and the risk of pneumonia in humans. OBJECTIVE: We examined the association between green tea consumption and death from pneumonia in humans. DESIGN: We conducted a population-based cohort study, with follow-up from 1995 to 2006. The participants were National Health Insurance beneficiaries in Japan (19,079 men and 21,493 women aged 40-79 y). We excluded participants for whom data on green tea consumption frequency were missing or who had reported a history of cancer, myocardial infarction, stroke, and extreme daily energy intake at baseline. We used Cox proportional hazards regression analysis to calculate hazard ratios (HRs) and their 95% CIs for death from pneumonia according to green tea consumption. RESULTS: Over 12 y of follow-up, we documented 406 deaths from pneumonia. In women, the multivariate HRs of death from pneumonia that were associated with different frequencies of green tea consumption were 1.00 (reference) for <1 cup/d, 0.59 (95% CI: 0.36, 0.98) for 1-2 cups/d, 0.55 (95% CI: 0.33, 0.91) for 3-4 cups/d, and 0.53 (95% CI: 0.33, 0.83) for > or =5 cups/d, respectively (P for trend: 0.008). In men, no significant association was observed. CONCLUSION: Green tea consumption was associated with a lower risk of death from pneumonia in Japanese women.

Coffee consumption and the risk of oral, pharyngeal, and esophageal cancers in Japan: the Miyagi Cohort Study.

An inverse association between coffee consumption and the risk of oral, pharyngeal, and esophageal cancers has been suggested in case-control studies, but few results from prospective studies are available. Data from the Miyagi Cohort Study in Japan were used to clarify the association between coffee consumption and the risk of these cancers. Information about coffee consumption was obtained from self-administered food frequency questionnaires in 1990. Among 38,679 subjects aged 40-64 years with no previous history of cancer, 157 cases of oral, pharyngeal, and esophageal cancers were identified during 13.6 years of follow-up. Hazard ratios were estimated by the Cox proportional hazards regression model. The risk of oral, pharyngeal, and esophageal cancers was inversely associated with coffee consumption. The multivariate-adjusted hazard ratio of these cancers for > or =1 cups of coffee per day compared with no consumption was 0.51 (95% confidence interval: 0.33, 0.77). This inverse association was consistent regardless of sex and cancer site and was observed both for subjects who did not drink or smoke and for those who currently drank or smoked at baseline. In conclusion, coffee consumption was associated with a lower risk of oral, pharyngeal, and esophageal cancers, even in the group at high risk of these cancers.

Alcohol consumption and suicide mortality among Japanese men: the Ohsaki Study.

The risk of suicide is well known to be increased among heavy alcohol drinkers. However, whether the risk is increased or decreased among light drinkers is still under debate. We investigated this association in a population-based sample of men in Japan. The Ohsaki Study was a population-based, prospective cohort study among Japanese adults aged from 40 to 79 years. Between October and December, 1994, 22,804 men in Miyagi Prefecture, Japan, completed a questionnaire on various health-related lifestyles, including alcohol drinking. During the subsequent 7 years follow-up, 73 participants committed suicide. We used the Cox proportional hazards regression model to estimate the hazard ratio (HR) for suicide mortality according to the quantity of alcohol consumed daily, with adjustment for potential confounders. There was a statistically significant positive and linear association between the amount of alcohol consumed and the risk of suicide: the multivariate HRs in reference to nondrinkers (95% confidence interval) were 1.2 (0.5-2.7), 1.5 (0.7-3.4), and 2.4 (1.2-4.6) in current drinkers who consumed /=45.6g of alcohol per day, respectively (P-trend=.016). Even after the early death cases were excluded, a significant linear association was observed between alcohol consumption and the risk of suicide, with the risk of suicide also being nonsignificantly higher among the light drinkers than among nondrinkers (multivariate HR=1.7). This prospective cohort study indicated a positive linear association between alcohol consumption and the risk of suicide, and the suicide risk among the light drinkers was not decreased as compared with that in nondrinkers.

Coffee consumption and the risk of colorectal cancer: a prospective cohort study in Japan.

An inverse association between coffee consumption and the risk of colorectal cancer has been reported in several case-control studies, but results from prospective cohort studies have been inconclusive. We conducted a prospective cohort study among a Japanese population to clarify the association between coffee consumption and the risk of colorectal cancer incidence. We used data from the Miyagi Cohort Study for this analysis. Usable self-administered questionnaires about coffee consumption were returned from 22,836 men and 24,769 women, aged 40-64 years, with no previous history of cancer. We used the Cox proportional-hazard regression model to estimate hazard ratios and 95% confidence intervals. During 11.6 years of follow-up (425,303 person-years), we identified 457 cases of colorectal cancer. Coffee consumption was not associated with the incidence of colorectal, colon or rectal cancer. The multivariate-adjusted hazard ratio (95% confidence interval) of colorectal cancer incidence for 3 or more cups of coffee per day as compared with no consumption was 0.95 (0.65-1.39) for men and women (p for trend = 0.55), 0.91 (0.56-1.46) for men (p for trend = 0.53) and 1.16 (0.60-2.23) for women (p for trend = 0.996). Coffee consumption was also not associated with incidence of either proximal or distal colon cancer. We conclude that coffee consumption is not associated with the incidence risk of colorectal cancer in the general population in Japan.