Dairy consumption and incident risk of thyroid cancer in Japan: a pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study.

PURPOSE: The impact of dairy consumption on thyroid cancer is unclear. The purpose of this study was to elucidate the association between dairy consumption and the risk of thyroid cancer in Japanese people. METHODS: The association between dairy consumption and the risk of thyroid cancer in Japanese people was examined by conducting a pooled analysis of two prospective studies of residents in Miyagi Prefecture, Japan. Data from 64,340 men and women aged 40-79 years registered in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994 were analyzed. Dairy consumption was assessed at baseline using a self-administered food frequency questionnaire and was divided into quartiles based on the weight (in grams) of total dairy consumption per day. RESULTS: During 1,075,018 person-years of follow-up, there were 190 incident cases of thyroid cancer (29 men and 161 women). The hazard ratios (HRs) and 95% confidence intervals (CIs) for thyroid cancer incidence in the highest quartile of dairy consumption compared with the lowest quartile were 0.83 (95% CIs 0.28-2.43, P-trend = 0.823) for men and 0.67 (95% CIs 0.42-1.06, P-trend = 0.056) for women. After stratification for BMI, a decreased risk was observed in women with BMI ≥ 25 kg/m2 (HRs: 0.37, 95% CIs 0.18-0.79, P-trend = 0.010). CONCLUSION: Dairy consumption is inversely associated with the risk of thyroid cancer in women with BMI ≥ 25 kg/m2.

How Long Would You Like to Live? A 25-year Prospective Observation of the Association Between Desired Longevity and Mortality.

BACKGROUND: Desired longevity represents how strongly people esteem possible extensions of their own lifetime. The association between desired longevity and mortality risk has been reported in only one prospective study, which examined a small sample of older participants. We aimed to examine the hypothesis that desired longevity at middle-age predicted long-term survival. METHODS: In the prospective cohort study, residents aged 40-64 years were asked how long they would like to live and asked to choose one from three options: longer than, as long as, or shorter than the life expectancy. We used Cox proportional hazards model to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality according to the three groups for desired longevity, treating the "longer than" group as the reference. We conducted mediation analysis to investigate the mechanism for the association between desired longevity and mortality. RESULTS: We recruited 39,902 residents to the study. Risk of all-cause mortality was significantly higher in the "shorter than" group (HR 1.12; 95% CI, 1.04-1.21). The association was independent of sex, age, marital status, education, medical history, and health status. Regarding cause of death, mortality risk of cancer (HR 1.14; 95% CI, 1.00-1.29) and suicide (HR 2.15; 95% CI, 1.37-3.38) were also higher in the "shorter than" group. The unhealthy lifestyle mediated this association with all-cause mortality by 30.4%. CONCLUSION: Shorter desired longevity was significantly associated with an increased risk of all-cause mortality, and mortality from cancer and suicide. Lifestyle behaviors particularly mediated this association.

Changes in time spent walking and disability-free life expectancy in Japanese older people: The Ohsaki Cohort 2006 Study.

An increase in time spent walking is significantly associated with lower risks of mortality and disability. This study aimed to investigate the association between changes in time spent walking and disability-free life expectancy (DFLE) in community-dwelling older people. Thirteen-year follow-up data from a cohort study of 7105 Japanese older adults (age ≥ 65 years) in 2006 were analyzed. Information on time spent walking was collected using questionnaires at two time points (1994 and 2006). Based on this information, the participants were categorized into four groups according to changes in time spent walking: remained inactive, became inactive, became active, and remained active. DFLE was defined as the average number of years a person could expect to live without disability. The multistate life table method using a Markov model was used to calculate DFLE. Of those who were inactive in 1994, DFLE of those who became active in 2006 (20.30 years in men; 24.06 years in women) was longer by about 2 years than of those who remained inactive (17.96 years in men; 21.87 years in women), and it was as long as those who remained active (20.34 years in men; 24.16 years in women). The 2-year difference in DFLE did not change after the participants were stratified by body mass index, motor function, cognitive function, and history of diseases. Increase in time spent walking is associated with longer DFLE in Japanese older people. Encouraging simple physical activity such as walking at the population level could increase life-years lived in good health.

How does social support modify the association between psychological distress and risk of suicide death?

BACKGROUND: Social support (SS) has been reported as a factor preventing suicide death, but whether this association is independent of mental status is unclear. The present study examined the effect modification of SS on the association between psychological distress status and risk of suicide death. METHODS: Follow-up data for 43,015 subjects participating in a prospective cohort study were analyzed. At baseline, the subjects were asked about SS and mental status with the Kessler six-item Distress (K6) Scale. A Cox model was used to estimate the multivariate-adjusted hazard ratios (HRs) of suicide death according to two levels of psychological distress (K6 ≤ 4, K6 ≥ 5). The HRs in each SS subtype (emotional and instrumental) were also calculated. RESULTS: There was a significant association between SS and a lower risk of suicide death in the stratum of K6 ≥ 5, with an HR of 0.58 (95% confidence interval, 0.35-0.96). On the other hand, the association with the K6 ≤ 4 strata was not significant. CONCLUSION: SS appears to be associated with a lower risk of suicide death only among participants with moderate or severe psychological distress. These results imply that early detection of psychological distress and provision of SS is important for preventing suicide death.

Association of dairy intake with all-cause, cancer, and cardiovascular disease mortality in Japanese adults: a 25-year population-based cohort.

PURPOSE: The association between dairy intake and mortality remains uncertain, and evidence for the Japanese population is scarce. We aimed to investigate the association between dairy intake and all-cause, cancer, and cardiovascular disease (CVD) mortality in Japanese adults. METHODS: A total of 34,161 participants (16,565 men and 17,596 women) aged 40-64 years without a history of cancer, myocardial infarction, or stroke at baseline were included in the analysis, using data from the Miyagi Cohort Study initiated in 1990. Milk, yogurt, and cheese intake were obtained using a validated food frequency questionnaire. Total dairy intake was calculated as the sum of milk, yogurt, and cheese intake and then categorized by quartile. The outcomes were all-cause, cancer, and CVD mortality. Cox proportional hazards regression models were used to estimate multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality risks. RESULTS: During 750,016 person-years of follow-up, the total number of deaths was 6498, including 2552 deaths due to cancer and 1693 deaths due to CVD. There was no association between total dairy intake and all-cause, cancer, and CVD mortality for both men and women. We also examined the associations between subgroup dairy products and mortality. For milk and yogurt intake, our results suggest null associations. However, cheese intake was modestly associated with lower all-cause mortality in women; compared with non-consumers, the multivariable HRs (95%CIs) were 0.89 (0.81-0.98) for 1-2 times/month, 0.88 (0.78-1.00) for 1-2 times/week, and 0.89 (0.74-1.07) for 3 times/week or almost daily (p trend = 0.016). CONCLUSION: Dairy intake was not associated with mortality in Japanese adults, except for limited evidence showing a modest association between cheese intake and a lower all-cause mortality risk in women.

Dairy intake and incident functional disability among older Japanese adults: the Ohsaki Cohort 2006 Study.

PURPOSE: Previous studies have investigated the association between dairy intake and functional disability, but their results were inconsistent. Our study aimed to investigate whether dairy intake may protect against incident functional disability among Japanese older adults. METHODS: We conducted a longitudinal analysis of dairy intake with incident functional disability in a prospective cohort study of 11,911 Japanese individuals aged ≥ 65 years who were followed up for 8.2 years on average. Data on milk, yogurt, and cheese intake were collected using a validated food frequency questionnaire. Total dairy intake was the sum of the daily intake of milk, yogurt, and cheese, which was sex-specifically categorized in quintiles. Data on functional disability were retrieved from the public Long-term Care Insurance database. The Cox proportional hazards model was used to estimate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95%CIs) for incident functional disability. RESULTS: During 97,234 person-years of follow-up, 4874 persons (40.9%) were ascertained as having functional disability. Our study suggested a null association between total dairy intake and incident risk of functional disability; compared to Q1 (the lowest quintile) group, the multivariable-adjusted HRs (95%CIs) were 0.96 (0.88-1.05) for Q2, 0.93 (0.85-1.02) for Q3, 0.93 (0.85-1.02) for Q4, and 1.01 (0.92-1.10) for Q5 (p-trend = 0.840). We did not find any associations between milk, yogurt, or cheese intake and incident risk of functional disability. CONCLUSION: We found no evidence showing that dairy intake was associated with functional disability among Japanese older adults.

Association Between Long-term Weight Change Since Midlife and Risk of Incident Disabling Dementia Among Elderly Japanese: The Ohsaki Cohort 2006 Study.

BACKGROUND: Both weight loss and cognitive impairment are common in late-life, but it remains unknown whether weight change is associated with risk of incident dementia among elderly Japanese. Our study aimed to investigate the association between long-term weight change since midlife and risk of incident disabling dementia using a community-based cohort study of elderly Japanese. METHODS: In 2006, we conducted a cohort study of 6,672 disability-free Japanese adults aged ≥65 years. In both 1994 and 2006, the participants reported their weight using a self-reported questionnaire. Based on weight obtained at these two time points, participants were classified into: stable weight (-1.4 to +1.4 kg), weight gain (≥+1.5 kg), and weight loss of -2.4 to -1.5 kg, -3.4 to -2.5 kg, -4.4 to -3.5 kg, -5.4 to -4.5 kg, and ≥-5.5 kg. Incident disabling dementia was retrieved from the public Long-term Care Insurance database. Participants were followed-up for 5.7 years (between April 2007 and November 2012). Cox proportional hazards model was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident disabling dementia. RESULTS: During 32,865 person-years of follow-up, 564 participants were ascertained as having incident disabling dementia. Compared with stable weight, the multivariable-adjusted HRs were 0.97 (95% CI, 0.70-1.34) for weight loss of -2.4 to -1.5 kg, 0.98 (95% CI, 0.70-1.38) for -3.4 to -2.5 kg, 1.28 (95% CI, 0.91-1.81) for -4.4 to -3.5 kg, 1.27 (95% CI, 0.92-1.77) for -5.4 to -4.5 kg, and 1.64 (95% CI, 1.29-2.09) for ≥-5.5 kg. CONCLUSION: Our study suggested that a ≥-3.5 kg weight loss over 12 years might be associated with higher risk of incident disabling dementia among elderly Japanese.

Association Between Social Participation and Disability-free Life Expectancy in Japanese Older People: The Ohsaki Cohort 2006 Study.

BACKGROUND: Although social participation has been reported to be associated with significantly lower risks of mortality and disability, to our knowledge, no study has estimated its impact on disability-free life expectancy (DFLE). Therefore, this study aimed to investigate the association between social participation and DFLE in community-dwelling older people. METHODS: We analyzed 11-year follow-up data from a cohort study of 11,982 Japanese older adults (age ≥65 years) in 2006. We collected information on the number of social participations using a questionnaire. Using this information, we categorized the participants into four groups. DFLE was defined as the average number of years a person could expect to live without disability. The multistate life table method using a Markov model was employed for calculating DFLE. RESULTS: The results revealed that DFLE according to the number of social participations was 17.8 years (95% confidence interval [CI], 17.3-18.2) for no activities, 20.9 (95% CI, 20.4-21.5) for one activity, 21.5 (95% CI, 20.9-22.0) for two activities, and 22.7 (95% CI, 22.1-23.2) for three activities in men, and 21.8 (95% CI, 21.5-22.2), 25.1 (95% CI, 24.6-25.6), 25.3 (95% CI, 24.7-25.9), and 26.7 years (95% CI, 26.1-27.4), respectively, in women. This difference in DFLE did not change after the participants were stratified for smoking, body mass index, physical activity, and depression. CONCLUSION: Social participation is associated with longer DFLE among Japanese older people; therefore, encouraging social participation at the population level could increase life-years lived in good health.

Association between the number of remaining teeth and disability-free life expectancy, and the impact of oral self-care in older Japanese adults: a prospective cohort study.

BACKGROUND: Tooth loss has been reportedly associated with shorter disability-free life expectancy (DFLE). However, no study has explored whether oral self-care offsets reduction in DFLE. The present study aimed to assess the association between oral self-care and DFLE in older individuals with tooth loss. METHODS: Data on the 13-year follow-up from a cohort study of 14,206 older Japanese adults aged ≥ 65 years in 2006 were analyzed. Information on the number of remaining teeth was collected using a questionnaire, and the participants were then categorized into three groups (0-9, 10-19, and ≥ 20 teeth). Additionally, "0-9" and "10-19" groups were divided into two subgroups based on whether they practiced oral self-care. DFLE was defined as the average number of years a person could expect to live without disability, and was calculated by the multistate life table method based on a Markov model. RESULTS: DFLE (95% confidence interval) was 19.0 years (18.7-19.4) for 0-9 teeth, 20.1 (19.7-20.5) for 10-19 teeth, and 21.6 (21.2-21.9) for ≥ 20 teeth for men. For women, DFLE was 22.6 (22.3-22.9), 23.5 (23.1-23.8), and 24.7 (24.3-25.1), respectively. Practicing oral self-care was associated with longer DFLE, by 1.6-1.9 years with brushing ≥ 2 times a day in people with 0-9 and 10-19 teeth, and by 3.0-3.1 years with the use of dentures in those with 0-9 teeth. CONCLUSIONS: Practicing oral self-care is associated with an increase in DFLE in older people with tooth loss.

Association between adherence to the Japanese diet and all-cause and cause-specific mortality: the Japan Public Health Center-based Prospective Study.

PURPOSE: The present study aimed to examine the association between adherence to the Japanese diet and the subsequent risk of all-cause and cause-specific mortality using a large-scale cohort from settings all over Japan. METHODS: We analyzed data from a cohort study of 92,969 Japanese adults aged 45-74 years, covering 11 public health center areas nationwide. We collected dietary information using a validated 147-item food frequency questionnaire. Adherence to the Japanese diet consisting of eight components (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, and green tea; low intake of beef and pork) was assessed using 8-item Japanese Diet Index (JDI8) score, with scores ranging from 0 to 8. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cause-specific mortality. RESULTS: During a median follow-up of 18.9 years, we documented 20,596 deaths. A higher JDI8 score was significantly associated with a lower risk for all-cause and cardiovascular disease (CVD) mortality. The multivariable-adjusted HR of all-cause and CVD mortality for the highest JDI8 score group (score of 6-8) versus the lowest JDI8 score group (score of 0-2) were 0.86 (95% CI 0.81-0.90, P trend < 0.001), and 0.89 (95% CI 0.80-0.99, P trend = 0.007), respectively. CONCLUSIONS: Adhering to the Japanese diet, as assessed by the JDI8, was associated with a decreased risk of all-cause and CVD mortality among adults living in multiple areas across Japan.

Mushroom consumption and incident risk of prostate cancer in Japan: A pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study.

In vivo and in vitro evidence has shown that mushrooms have the potential to prevent prostate cancer. However, the relationship between mushroom consumption and incident prostate cancer in humans has never been investigated. In the present study, a total of 36,499 men, aged 40-79 years, who participated in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994 were followed for a median of 13.2 years. Data on mushroom consumption (categorized as <1, 1-2 and ≥3 times/week) was collected using a validated food frequency questionnaire. Cox proportional hazards regression analysis was used to estimate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer incidence. During 574,397 person-years of follow-up, 1,204 (3.3%) cases of prostate cancer were identified. Compared to participants with mushroom consumption <1 time/week, frequent mushroom intake was associated with a decreased risk of prostate cancer (1-2 times/week: HRs [95% CIs] = 0.92 [0.81, 1.05]; ≥3 times/week: HRs [95% CIs] = 0.83 [0.70, 0.98]; p-trend = 0.023). This inverse relationship was especially obvious among participants aged ≥50 years and did not differ by clinical stage of cancer and intake of vegetables, fruit, meat and dairy products. The present study showed an inverse relationship between mushroom consumption and incident prostate cancer among middle-aged and elderly Japanese men, suggesting that habitual mushroom intake might help to prevent prostate cancer.

Fish consumption and risk of incident dementia in elderly Japanese: the Ohsaki cohort 2006 study.

Fish harbour many types of nutrients that are beneficial for preventing cognitive decline. Therefore, habitual fish intake might contribute to a lower risk of incident dementia. However, few prospective cohort studies have investigated fish consumption in relation to incident dementia, and their findings have been inconsistent. To investigate the association between fish consumption and the risk of incident dementia, we collected data on the consumption of fish and other foods using an FFQ in a baseline survey of individuals aged ≥65 years living in Ohsaki City, Japan. After 5·7 years of follow-up, the incidence of dementia was 1118 (8·5 %) among 13 102 participants. We then used a multivariate-adjusted Cox model to estimate hazard ratios (HR) and 95 % CI. Compared with subjects with the lowest fish intake (Q1), the multivariate HR were 0·90 (95 % CI 0·74, 1·11) for Q2, 0·85 (95 % CI 0·73, 0·99) for Q3 and 0·84 (95 % CI 0·71, 0·997) for Q4 (Ptrend = 0·029). Such associations were also observed even after excluding participants who were diagnosed with dementia in the first 2 years of follow-up and those who had poorer cognitive function at baseline. In conclusion, an association was observed between higher fish consumption and a lower risk of incident dementia among healthy elderly people without disability. These findings suggest that habitual fish intake may be beneficial for the prevention of dementia.

A cross-sectional study of the associations between the traditional Japanese diet and nutrient intakes: the NILS-LSA project.

BACKGROUND: Although our previous study using a food frequency questionnaire simulated nutritional characteristics of the traditional Japanese diet, this issue has not been sufficiently evaluated. This study was conducted to examine the relationship between the traditional Japanese diet and nutrient density (ND). METHODS: A cross-sectional study employing the dietary record method was conducted among 2221 community-dwelling Japanese adults (40-88 years) living in Aichi Prefecture, Japan, in 2006-2008. Based on previous studies, a 9-component Japanese Diet Index (JDI) and a 12-component modified JDI (mJDI12) were defined. To develop a new weighted index, a multiple linear regression model was used to select food components which were significantly associated with an ND score (integrated by 11 nutrient components) from the mJDI12 and weight them. Correlation analyses were performed between JDI, mJDI12, the new weighted JDI score and the ND score and its 11 nutrient components. The findings were validated with data from 2008 to 2010 by assessing the associations between the JDIs scores and the ND score. RESULTS: Scores of the JDI and mJDI12 were positively correlated with the ND score (corresponding Spearman's ρ [95% confidence interval; CI], 0.34 [0.31, 0.38] and 0.44 [0.41, 0.48], respectively; P < 0.05 for both). Among the mJDI12, 9 food components (rice, fish and shellfish, green and yellow vegetables, seaweed, green tea, beef and pork, soybeans and soybean foods, fruit, and mushrooms) significantly associated with the ND score. All of these 9 components were weighted and a new weighted JDI (wJDI9) was developed. The wJDI9 score was also positively correlated with the ND score (Spearman's ρ [95% CI] = 0.61 [0.58, 0.64]; P < 0.05). However, scores for all 3 indices were positively correlated with sodium intake. The wJDI9 score obtained using dietary record data from 2008 to 2010 was also positively correlated with the ND score (Spearman's ρ [95% CI] = 0.61 [0.58, 0.64]; P < 0.05). CONCLUSIONS-: Adhering to a traditional Japanese diet as defined by the JDI was associated with good ND. Furthermore, the modified indices (mJDI12 and wJDI9) had a higher performance for ND. However, all of the indices were correlated with high sodium intake.

Association between education and disability-free life expectancy among Japanese older people: The Ohsaki Cohort 2006 study.

BACKGROUND: Higher education level is associated with longer disability-free life expectancy (DFLE). However, evidence is scarce regarding factors that can contribute to eliminating inequality in DFLE according to education level. This study aimed to clarify the association between education and DFLE and estimate whether DFLE in people with lower education may increase to the same level as that in people with higher education through social participation. METHODS: We analyzed data from 13,849 Japanese people aged 65 years and older who participated in a 13-year prospective study. At baseline, we collected information on education levels (low, middle, or high) and social participation. DFLE was defined as the average duration people expect to live without disability. To calculate DFLE for each education level group, the multistate life table method was employed using a Markov model. RESULTS: At the age of 65 years, DFLE (95 % confidence interval [CI]) in women with low education was 21.3 years (20.8-21.8) without social participation and 24.3 (23.8-24.9) with social participation. In the middle education group, DFLE was 22.1 (21.6-22.6) without social participation and 25.0 (24.6-25.5) with social participation. In the high education group, DFLE was 22.1 (21.5-22.8) without social participation and 25.5 (25.0-26.0) with social participation. Similar results were found for men. CONCLUSIONS: DFLE in people with low or middle education with social participation was almost the same as that in those with high education with social participation, suggesting the possibility that disparities in DFLE by education level could be offset by promoting social participation in older adults.

Effect of social participation on the association between frailty and disability.

OBJECTIVES: To examine whether social participation affects the association between frailty and disability. METHODS: A baseline survey conducted from December 1 to 15, 2006, included 11,992 participants who were classified based on the Kihon Checklist into three categories and based on the number of activities in which they socially participated into four categories. The study outcome, incident functional disability, was defined as in Long-Term Care Insurance certification. A Cox proportional hazards model was used to calculate hazard ratios (HRs) for incident functional disability according to frailty and social participation categories. Combination analysis was performed between the nine groups using the above-mentioned Cox proportional hazards model. RESULTS: During the 13-year follow-up (107,170 person-years), 5,732 incident cases of functional disability were certified. Compared with the robust group, the other groups had significantly higher incident functional disability. However, the HRs for those participating in social activities were lower than that for those not participating in any activity [1.52 (pre-frail + none group); 1.31 (pre-frail + one activity group); 1.42 (pre-frail + two activities group); 1.37 (pre-frail + three activities group); 2.35 (frail + none group); 1.87 (frail + one activity group); 1.85 (frail + two activities group); and 1.71 (frail + three activities group)]. CONCLUSIONS: The risk of functional disability for those participating in social activities was lower than that for those not participating in any activity, irrespective of being pre-frail or frail. Comprehensive social systems for disability prevention need to focus on social participation in frail older adults.

Association between number of remaining teeth and healthy aging in Japanese older people: The Ohsaki Cohort 2006 Study.

AIM: Maintaining ≥20 teeth is a public health goal worldwide. Healthy aging, which includes psychological and social well-being, as well as physical indicators, has attracted a great deal of attention with the progression of aging societies. However, no studies have examined the association between the number of remaining teeth and healthy aging. This study aimed to investigate the association between the number of remaining teeth and healthy aging. METHODS: This community-based longitudinal cohort study included 8300 Japanese people aged ≥65 years who were free of disability and depression in the baseline survey in 2006. The participants were categorized into four groups according to the number of remaining teeth at baseline: 0-9, 10-19, 20-24 and ≥25. The primary outcome was healthy aging (defined as meeting all four of the following criteria: free of disability, free of depression, high health-related quality of life and high life satisfaction), as assessed by a questionnaire survey carried out in 2017. Multiple logistic regression was used to calculate the corresponding odds ratios and 95% confidence intervals. RESULTS: During about 11 years of follow-up, 621 (7.5%) participants attained healthy aging. Participants with ≥20 remaining teeth showed a higher healthy aging rate. Compared with participants with 0-9 teeth, the multivariate-adjusted odds ratios (95% confidence intervals) for 10-19, 20-24 and ≥25 teeth were 0.98 (0.77-1.26), 1.28 (1.01-1.63) and 1.59 (1.24-2.03), respectively. CONCLUSIONS: These findings suggest that maintaining ≥20 teeth was associated with healthy aging. Geriatr Gerontol Int 2022; 22: 68-74.

High Mortality in an Older Japanese Population with Low Forced Vital Capacity and Gender-Dependent Potential Impact of Muscle Strength: Longitudinal Cohort Study.

Generally, weak muscle power is associated with high mortality. We aimed to evaluate the unknown association between % predicted value forced vital capacity (FVC% predicted) and mortality in asymptomatic older people, and the impact of muscle power on this association. We analyzed the Tsurugaya cohort that enrolled Japanese people aged ≥70 for 15 years with Cox proportional hazards model. Exposure variables were FVC% predicted and leg power. The outcome was all-cause mortality. The subjects were divided into quartiles by FVC% predicted or leg power, or into two groups by 80% for FVC% predicted or by the strongest 25% for leg power. Across 985 subjects, 262 died. The males with lower FVC% predicted exhibited higher mortality risks. The hazard ratio (HR) was 2.03 (95% CI 1.30−3.18) at the lowest relative to the highest groups. The addition of leg power reduced the HR to 1.78 (95% CI 1.12−2.80). In females, FVC% predicted under 80% was a risk factor and the HR was 1.67 (95% CI 1.05−2.64) without the effect of leg power. In FVC% predicted <80% males HRs were 2.44 (95% CI 1.48−4.02) in weak and 1.38 (95% CI 0.52−3.64) in strong leg power males, relative to ≥80% and strong leg power males. Low FVC% predicted was associated with high mortality with potential unfavorable effects of weak leg power in males.

Social Participation and Healthy Aging Among the Older Japanese: The Ohsaki Cohort 2006 Study.

BACKGROUND: Our study examined the association between social participation and healthy aging using a community-based cohort study among Japanese older adults. METHODS: This prospective study was conducted in Ohsaki City, Japan, and included 7226 participants aged ≥65 years at the baseline survey in 2006. We obtained information on frequency of participation in 3 types of community activities (ie, neighborhood activities, hobbies, and volunteer activities) at baseline. Exposure was measured by the number of types of community activities participated in and participants were categorized into 4 groups (ie, none, 1 type, 2 types, and 3 types). The primary outcome was healthy aging as assessed by a questionnaire survey conducted in 2017, and was defined as meeting the following 4 criteria: free of disability, free of depression, high health-related quality of life, and high life satisfaction. We used multiple logistic regression models to calculate the corresponding odds ratios and 95% confidence intervals. RESULTS: During 11 years of follow-up, 574 (7.9%) participants attained healthy aging. Compared with participants not participating in any activity, the multivariable-adjusted odds ratios (95% confidence intervals) were 1.90 (1.40, 2.59) for those participating in 1 type, 2.49 (1.84, 3.38) for 2 types, and 3.06 (2.30, 4.07) for 3 types (p for trend < .0001). Furthermore, for each type of community activity, a higher frequency of participation was related to higher probability of healthy aging. CONCLUSIONS: Our study suggests that social participation is associated with the promotion of healthy aging, and that the benefits were observed across different types of community activities.

Japanese Diet and Mortality, Disability, and Dementia: Evidence from the Ohsaki Cohort Study.

The Japanese dietary pattern has long been discussed as one of the factors behind the longevity of Japanese people. However, the health benefits of the Japanese dietary pattern have not been fully elucidated. We published the first report in the world regarding the relation between the Japanese dietary pattern and cardiovascular disease mortality in 2007 using cohort studies including Japanese residents of Ohsaki City, Miyagi Prefecture, Japan. Since then, we have developed the Japanese Diet Index (JDI) that was based on previous findings to assess the degree of the Japanese dietary pattern and to advance the evidence on the health effects of the Japanese dietary pattern. So far, we have explored the associations between the JDI score (in quartiles) and various outcomes. For all-cause mortality, in comparison to Q1 (the lowest), the multivariable hazard ratios (HRs) and 95% confidence intervals (95%CIs) were 0.92 (0.85-1.00) for Q2, 0.91 (0.83-0.99) for Q3, and 0.91 (0.83-0.99) for Q4 (the highest). For functional disability, the multivariable HRs (95%CIs) were 0.94 (0.81-1.09) for Q2, 0.90 (0.77-1.05) for Q3, and 0.79 (0.68-0.92) for Q4. For dementia, the multivariable HRs (95%CIs) were 0.88 (0.74-1.05) for Q2, 0.87 (0.73-1.04) for Q3, 0.79 (0.66-0.95) for Q4. In addition, people with higher adherence to the Japanese dietary pattern also showed decreases in disability and dementia risks. The purpose of this article was to review all six papers, summarize the health effects of the Japanese dietary pattern, and discuss implications for future research.

Relationship between maximum occlusal force and gastrointestinal cancer in community-dwelling older Japanese adults.

Globally, the cancer burden is expected to increase as populations are ageing. Therefore, cancer prevention among older age groups is important. This prospective cohort study examined the relationship between the number of remaining teeth, maximum occlusal force, and incidence of gastrointestinal cancer in community-dwelling older Japanese individuals using data from the Tsurugaya project; 847 participants were included. The exposure variables were the number of remaining teeth and the maximum occlusal force, with the outcome being the incidence of gastrointestinal cancer. Covariates were age, sex, medical history, smoking, alcohol consumption, educational attainment, and physical function. The Cox proportional hazard model was used to examine the relationship between the number of remaining teeth, maximum occlusal force, and incidence of gastrointestinal cancer. With a median follow-up of 7.6 years, 63 participants were confirmed to have gastrointestinal cancer. The risk of gastrointestinal cancer was significantly higher in those with an occlusal force lower than the median (hazard ratio, 2.80; 95% confidence interval, 1.54-5.10). No significant risk difference was found according to the number of remaining teeth. Low maximum occlusal force was associated with the incidence of gastrointestinal cancer in community-dwelling older Japanese adults.