An Optimal Dietary Pattern for Healthy Longevity: Scoping Differencing Review between the Mediterranean and the Japanese Diet

BACKGROUND

From the late 1980s to the early 1990s, micronutrients were associated with the concept of healthy aging and it was deemed as important to recognize eating lifestyles that better involved these healthy macronutrients.

METHODS

The present integrative differencing literature review aimed to identify correlations between healthy longevity and both the Mediterranean (MD) and the Japanese diet (JD).

RESULTS

A review of the primary and secondary literature was performed by consulting Embase and Medline (PubMed) databases. The bibliographic research focused on the critical reading of the studies in the last ten years. A total of 10 studies, 3 belonging to Embase and 7 to PubMed, were finally included, which exhaustively agreed with the inclusion criteria considered.

CONCLUSION

In all manuscripts selected, "over" elderly participants reported good adherence to both Mediterranean and Japanese eating behaviours, acceptable anthropometric characteristics, active social life, and regular physical activity.

Sex- and Age-Specific Associations Between Metabolic Syndrome and Future Functional Disability in the Japanese Older Population

Whether the association between metabolic syndrome (MetS) and functional disability differs depending on sex or age remains unknown. To determine the association between MetS and functional disability in older people separately by sex and age groups. A total of 11 083 participants (4407 men and 6676 women) aged 65 years or over without functional disability were enrolled. MetS was defined according to the revised NCEP ATP III guidelines. Functional disability was defined by a new certification in the long-term care insurance in Japan. Cox proportional hazards models were used to assess the risk of functional disability with adjustment for possible confounding factors. Over the mean observation period of 10.5 years, 1282 men and 2162 women experienced functional disability. For those aged 65 to 74 years, HRs (95% CIs) for functional disability in the MetS group were 1.33 (1.07-1.66) in men and 1.15 (1.000-1.32) in women. For those aged 75 years or older, there was no significant association in men or women. In subjects with a severe care need level, there was a marginal significant association in men aged 65 to 74 years. Among the MetS components that independently increased the risk of functional disability were glucose intolerance and elevated blood pressure (men and women aged 65-74 years), obesity (women aged 65-74 years), and glucose intolerance (women aged 75 years or older). MetS contributed to an increase in a high risk of future functional disability among individuals aged 65 to 74 years. In this age group, improvement of lifestyle, health promotion and interventions for MetS from middle age may prevent future functional disability.

Association between C-Reactive Protein Levels and Functional Disability in the General Older-Population: The Takashima Study

AIMS

High-sensitivity C-reactive protein (hsCRP) associates with atherosclerotic diseases such as stroke. However, previous results on the association between hsCRP levels and functional disability were controversial.

METHODS

We analyzed 2,610 men and women who did not exhibit functional disability or death within the first 3 years of the baseline survey and those aged 65 years or older at the end of follow-up. The levels of hsCRP were assessed using latex agglutination assay at baseline survey from 2006 to 2014. Functional disability was followed up using the long-term care insurance (LTCI) program until November 1, 2019. Functional disability was defined as a new LTCI program certification. Cox proportional hazards model with competing risk analysis for death was used to evaluate the association between hsCRP levels and future functional disability.

RESULTS

During a 9-year follow-up period, we observed 328 cases of functional disability and 67 deaths without prior functional disability incidence. The multivariable-adjusted hazard ratio (HR, 95% confidence interval [CI]) of functional disability in log-transferred hsCRP levels was 1.43 (1.22-1.67) in men and 0.97 (0.81-1.15) in women. When hsCRP level was analyzed as a categorical variable, low hsCRP levels (＜1.0 mg/l) as the reference, the multivariable-adjusted HR (95% CI) of functional disability in high hsCRP levels (≥ 3.0 mg/l) was 2.37 (1.56-3.62). Similar results were observed when stratified by sex, but it was not significant in women.

CONCLUSIONS

This study demonstrates that low-grade systemic inflammation to assess hsCRP might predict the future incidence of functional disability, especially in men.

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.

Risk Factors of Long-Term Care Insurance Certification in Japan: A Scoping Review

This study aimed to review evidence on future long-term care associated with pre-existing factors among community-dwelling Japanese older adults. We systematically searched cohort and nested case-control studies published between 2000 and 2019 that assessed long-term care certification using the PubMed, CINAHL, and EMBASE databases. The relationship between long-term care insurance information and risk factors was investigated. The protocol was registered with the Open Science Framework. We extracted 91 studies for synthesis, including 84 prospective cohort studies, 1 retrospective cohort study, and 6 nested case-control studies. Certification for long-term care was classified into two endpoints: onset of functional disability and dementia. There were 72 studies that used long-term care certification as a proxy for functional disability, and 22 used long-term care information to indicate the onset of dementia. Common risk factors related to functional disability were physical function, frailty, and oral condition. Motor function and nutritional status were common risk factors for dementia. We found consistent associations between premorbid risk factors and functional disability and dementia. The accumulation of evidence on the incidence of long-term care and associated factors can aid the development of preventive measures. Future studies should aim to integrate this evidence.

Association between Stress-Coping Strategy and Functional Disability in the General Older Adult Population: The Takashima Study

BACKGROUND

Both physical and psychological factors have been associated with functional disability. However, the associations between stress-coping strategies and future functional disability remain unclear.

METHODS

We analyzed 2,924 participants who did not have incidence of functional disability or death within the first 3 years of the baseline survey and were aged 65 years or more at the end of follow-up. Stress-coping strategies were assessed via a self-administered questionnaire (emotional expression, emotional support seeking, positive thought, problem-solving, and disengagement) in a baseline survey from 2006 to 2014. Levels of coping strategies were classified as low, middle, and high based of frequency. Functional disability decline was followed up using the long-term-care insurance program until November 1, 2019. Functional disability decline was defined as a new long-term-care insurance program certification. Cox proportional hazards model with competing risk analysis for death was used to evaluate associations between coping strategy levels and functional disability.

RESULTS

During the follow-up period, we observed 341 cases of functional disability and 73 deaths without previous incidence of functional disability. A significant inverse association between "positive thought" and "problem-solving" and future functional disability was observed. Multivariable adjusted hazard ratios (95% confidence interval) for functional disability were 0.68 (0.51-0.92) for high levels of "positive thought" and 0.73 (0.55-0.95) for high levels of "problem-solving," compared with low levels of the coping strategies. The inverse association was stronger in men.

CONCLUSIONS

Some subcomponents of stress-coping strategies might be associated with future incidence of functional disability among older adults.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Comparing the differences in three measures of healthy life expectancy among prefectures in Japan

OBJECTIVE

An ecological study using secondary open data from Japanese government statistics was conducted. The study aimed to verify differences in three measures of healthy life expectancy (HLE); namely, disability-free life expectancy without activity limitation (DFLE-AL), life expectancy with self-perceived health (LE-SH), and disability-free life expectancy without care need (DFLE-CN).

RESULTS

Each HLE from 47 prefectures in 2010, 2013, and 2016 was extended over time. There were strong Cronbach's coefficient alpha (α) between DFLE-AL and LE-SH (Minimum α; 0.80, Maximum α; 0.90) as well as between LE and DFLE-CN (Minimum α; 0.92, Maximum α; 0.99) in both sexes in every data year. However, the other pairs had weaker associations. In regression analysis with each HLE as a dependent variable and aging rate, mortality, the proportion of unhealthy people as independent variables, the subjective unhealthy rate had significant standardized partial regression coefficients (β) in models with DFLE-AL and LE-SH as dependent variables (Minimum β; - 0.56, Maximum β; - 0.34). Therefore, DFLE-CN tended to differ from the other HLEs. The subjective unhealthy rate had a significant influence on DFLE-AL and LE-SH.

Epidemiologic Research on Healthy Life Expectancy and Proposal for Its Extension: A Revised English Version of Japanese in the Journal of the Japan Medical Association 2019;148(9):1781-4

Healthy life expectancy is an indicator that represents a composite of data on mortality and health status and is defined as the average number of years that a person can expect to live at a certain level of health. To extend people's healthy life expectancy, my colleague and I conducted a variety of epidemiologic research based upon community-based cohort studies and intervention trials. The findings from our prospective cohort studies included blood pressure reference values measured at home, green tea health benefit, Japanese dietary pattern, and feeling ikigai (a sense of life worth living) at daily life. Based upon these evidence, I have made some proposals toward extension of healthy life expectancy. In 2011, as the Chair of the Planning Committee for the Next National Health Promotion of Ministry of Health, Labor and Welfare (MHLW), I proposed that the Health Japan 21 (second term) should aim to extend healthy life expectancy to exceed the number of years extended in the total life expectancy, thus compressing the duration to be spent in an unhealthy state (compression of morbidity). In the interim evaluation of the Health Japan 21 (second term) in 2018, we were able to demonstrate that this goal is being achieved. Compared with 2010, in 2016, the increase in healthy life expectancy (1.72 years in men and 1.17 years in women) was higher than that of total life expectancy (1.43 years in men and 0.84 years in women). As a result, the duration to be spent in an unhealthy state was reduced by 0.29 years in men and by 0.33 years in women. It is important to note that Japan is the only country that has made progress in achieving compression of morbidity at the national level. We need to maintain this momentum of compressing morbidity.

Association between improved adherence to the Japanese diet and incident functional disability in older people: The Ohsaki Cohort 2006 Study

BACKGROUND & AIMS

Although it has been reported that the Japanese dietary pattern is associated with a lower risk of incident functional disability among older people, the potential benefits of improving adherence to the Japanese diet remain unclear. The aim of the present study was to evaluate the association between 12-year change in adherence to the Japanese diet and the subsequent risk of incident functional disability in older people in Japan.

METHODS

We analyzed 10-year follow-up data from a cohort study of 2923 Japanese older adults (age ≥65 years) in 2006. We collected dietary information using a validated 39-item food frequency questionnaire at two time points (1994 and 2006). Adherence to the Japanese diet (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, green tea; low intake of beef and pork, and coffee) was assessed using the Japanese Diet Index (JDI), which ranges from 0 to 9. Participants were categorized into five groups according to changes in the JDI score at these two time points. Data on incident functional disability from December 2006 to November 2016 were retrieved from the public long-term care insurance database. The Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident functional disability.

RESULTS

During 22,466 person-years of follow-up, 1093 cases of incident functional disability were documented. Compared with participants in the group with the largest decrease in the JDI score (≤-2), the multivariate-adjusted HR (95% CI) of incident functional disability was 0.77 (0.61-0.98) for those in the largest increase group (≥+2).

CONCLUSIONS

Improved adherence to the Japanese diet was associated with a significantly lower risk of incident functional disability in older people in Japan.

Effect of S-equol and Soy Isoflavones on Heart and Brain

BACKGROUND

Observational studies in Asia show that dietary intake of soy isoflavones had a significant inverse association with coronary heart disease (CHD). A recent randomized controlled trial (RCT) of soy isoflavones on atherosclerosis in the US, however, failed to show their benefit. The discrepancy may be due to the much lower prevalence of S-equol producers in Westerners: Only 20-30% of Westerners produce S-equol in contrast to 50-70% in Asians. S-equol is a metabolite of dietary soy isoflavone daidzein by gut microbiome and possesses the most antiatherogenic properties among all isoflavones. Several short-duration RCTs documented that soy isoflavones improves arterial stiffness. Accumulating evidence shows that both atherosclerosis and arterial stiffness are positively associated with cognitive decline/dementia. Therefore, potentially, soy isoflavones, especially S-equol, are protective against cognitive decline/dementia.

METHODS/RESULTS

This narrative review of clinical and epidemiological studies provides an overview of the health benefits of soy isoflavones and introduces S-equol. Second, we review recent evidence on the association of soy isoflavones and S-equol with CHD, atherosclerosis, and arterial stiffness as well as the association of atherosclerosis and arterial stiffness with cognitive decline/ dementia. Third, we highlight recent studies that report the association of soy isoflavones and S-equol with cognitive decline/dementia. Lastly, we discuss the future directions of clinical and epidemiological research on the relationship of S-equol and CHD and dementia.

CONCLUSIONS

Evidence from observational studies and short-term RCTs suggests that S-equol is anti-atherogenic and improves arterial stiffness and may prevent CHD and cognitive impairment/ dementia. Well-designed long-term (≥ 2years) RCTs should be pursued.

Dietary Inflammatory Index and Disability-Free Survival in Community-Dwelling Older Adults

Background: Previous studies have reported that a higher dietary inflammatory index (DII^®) score is related to a higher risk of mortality and conditions that result in functional disability, such as cardiovascular disease, dementia, and fractures. Although these findings suggest that higher DII scores would affect disability-free survival, this has never been investigated directly. The present study investigated the association between the DII score and disability-free survival. Methods: We analyzed follow-up data covering a 12-year period for 793 older adults (≥70 years) participating in a Japanese community-based cohort study. DII scores were computed on the basis of dietary intake and assessed using the Brief Self-Administered Diet History Questionnaire. Data on incident functional disability were retrieved from the public Long-Term Care Insurance database. We applied the Cox model for estimating the adjusted hazard ratios (HRs) of the composite outcome (incident functional disability or death) according to DII score tertiles (T1–T3). Results: The proportion of men was 47.3%; mean (SD) age was 75.2 (4.5) years. The 12-year incidence of the composite outcome was 65.5%. A higher DII score was related to a higher risk for the composite outcome: HRs (95% confidence interval) were 1.05 (0.84, 1.32) for T2 and 1.26 (1.01, 1.57) for T3 (p-trend = 0.040) compared to the most anti-inflammatory T1 reference (HR = 1.00). Conclusions: These results suggest that a pro-inflammatory diet might be a modifiable factor affecting disability-free survival in the older population. Additional prospective studies are needed to confirm this relationship.

The Impact of Psychological Distress on Incident Functional Disability in Elderly Japanese: The Ohsaki Cohort 2006 Study

Background: Although psychological distress is known to be a risk factor for death, there are relatively few data on the impact of psychological distress on incident functional disability in older adults. The aim of this study was to examine the impact of psychological distress on incident functional disability in older adults. Methods: We conducted a cohort study of 12,365 disability-free individuals aged ≥65 years who live in Ohsaki City, Japan. In 2006, the level of psychological distress was assessed using the K6 (range: 0⁻24 points). Data on 10-year functional disability were retrieved from the public Long-term Care Insurance database. The multivariate-adjusted hazard ratios (HRs) and population attributable fractions (PAFs) according to the K6 groups (<5, 5⁻9, 10⁻12, and ≥13 points) were estimated. Results: Among 94,636 person-years, incident functional disability occurred in 4533 persons (36.7%). Significantly higher risk was observed in higher K6 score groups. The multiple-adjusted HRs (95% CIs) of incident functional disability were 1.14 (1.06⁻1.22) for 5⁻9 points, 1.28 (1.15⁻1.43) for 10⁻12 points, and 1.62 (1.44⁻1.84) for ≥13 points, in comparison with <5 points (p-trend < 0.001). The PAFs in each of the K6 score groups were 3.0% for 5⁻9 points, 1.7% for 10⁻12 points, and 2.6% for ≥13 points. Conclusions: Even when mild to moderate, psychological distress had a considerable impact on incident functional disability in this cohort.

Association between social participation and incident risk of functional disability in elderly Japanese: The Ohsaki Cohort 2006

BACKGROUND

Although several longitudinal studies have examined the relationship between social participation and incident functional disability, the related mechanisms have remained unclear. The aim of this study was to examine the mechanisms linking social participation to incident functional disability.

METHODS

We analyzed follow-up data for 11,992 older adults (≥65 years) participating in a community-based, prospective cohort study covering a 9-year period. At the baseline, the subjects were asked about three types of participation in community activities (volunteering, hobbies, and neighborhood associations) and the frequency of their participation. Data on incident functional disability were retrieved from the public Long-term Care Insurance database. The Cox model was used to estimate the multivariate-adjusted hazard ratios of incident functional disability. We then conducted mediation analysis to assess the magnitude of the mediating effect.

RESULTS

Among 84,760 person-years of follow-up, there were 3,984 cases of incident functional disability. The hazard ratio was 0.79 (95% CI: 0.73-0.86) for participating in one type of activity, 0.82 (95% CI: 0.74-0.90) for two types of activity and 0.70 (95% CI: 0.64-0.77) for three types of activity in comparison with no participation in any activity. Among the estimated mediating effects, cognitive activity accounted for 9.3%, time spent walking for 8.3%, psychological state for 4.6%, and social support for 2.8% of the reduced risk of incident functional disability.

CONCLUSION

The results of this population-based cohort study indicate that cognitive activity and time spent walking are important mechanisms linking social participation to incident functional disability.

Effects of a Community-Based Program for Oral Health and Nutrition on Cost-Effectiveness by Preventing Disability in Japanese Frail Elderly: A Quasi-Experimental Study Using Propensity Score Matching

OBJECTIVE

In the Japanese Long-Term Care Insurance (LTCI) system, a community-based program for oral health and nutrition (OHN program) has been implemented with the aim of reducing incident disability and care costs. However, the effectiveness of this program has not been confirmed epidemiologically. The purpose of the present study was to test the hypothesis that the OHN program does reduce incident disability and care costs.

DESIGN

A prospective study with a 28-month follow-up period was conducted using data from administrative databases at Tagajo City, Japan. Among frail elderly persons (aged 65 years or more) who were enrolled in the LTCI program in Tagajo, 64 participants in the OHN program and 128 controls (nonparticipants) were selected by propensity score matching.

MEASUREMENTS

We used 2 types of outcome measure: composite outcome (incident disability and death) and care cost. Data on incident disability were retrieved from the public LTCI database. Care cost was defined as the total amount of LTCI service cost added to medical care cost.

RESULTS

The hazard ratio of composite outcome was significantly lower for the intervention group than for the control group (hazard ratio = 0.32, 95% confidence interval 0.12-0.82). Even when we set incident disability as an outcome, the hazard ratio for the intervention group did not change (hazard ratio = 0.33, 95% confidence interval 0.11-0.97). The mean cumulative care cost during the 28 months tended to be lower for the intervention group ($4893) than that for the control group ($5770), but this was not statistically significant by the gamma regression model (cost ratio = 0.85, P = .513). The mean care cost per unit follow-up period (1 month) for the intervention group was significantly lower (cost ratio = 0.54, P = .027).

CONCLUSIONS

The results of this study suggest that the OHN program is effective for preventing incident disability and, consequently, for saving care costs per unit survival period.

Impact of Pain on Incident Risk of Disability in Elderly Japanese: Cause-specific Analysis

BACKGROUND

Although several cross-sectional studies have reported that pain is associated with functional disability in the elderly, data regarding a longitudinal association between pain and disability are inconsistent. This study aimed to investigate the association of pain severity with subsequent functional disability due to all causes as well as stroke, dementia, and joint disease/fracture.

METHODS

The authors conducted a prospective cohort study of 13,702 Japanese individuals aged 65 yr or older. Information regarding pain severity during the previous 4 weeks and other lifestyle factors was collected via questionnaire in 2006. Data on the incidence of functional disability were retrieved from the Long-term Care Insurance database. Cox proportional hazards regression analysis was used to estimate the multivariate-adjusted hazard ratios for incident functional disability.

RESULTS

The authors documented 2,686 (19.6%) cases of incident functional disability. The multivariate hazard ratio of functional disability was 1.15 (95% CI, 1.02 to 1.31) among respondents with moderate pain and 1.31 (95% CI, 1.12 to 1.54) among respondents with severe pain in comparison with those without pain (P trend < 0.001). These positive associations were particularly remarkable for disability due to joint disease/fracture: the multivariate hazard ratio was 1.88 (95% CI, 1.37 to 2.58) for moderate pain and 2.76 (95% CI, 1.93 to 3.95) for severe pain (P trend < 0.001). There was a negative association between pain severity and disability due to dementia (P trend = 0.041) and no significant association between pain severity and disability due to stroke.

CONCLUSIONS

Among elderly Japanese individuals, the authors found a significant positive association between pain severity and future incident functional disability.

Sense of life worth living (ikigai) and incident functional disability in elderly Japanese: The Tsurugaya Project

OBJECTIVE

To test the hypothesis that elderly persons who feel ikigai (a sense of life worth living) have a lower risk of incident functional disability than those who do not. Recent studies have suggested that ikigai impacts on mortality. However, its impact upon disability is unknown. The aim of the present study was to investigate the association between ikigai and incident functional disability among elderly persons.

METHODS

We conducted a prospective cohort study of 830 Japanese elderly persons aged ≥70 years as a comprehensive geriatric assessment in 2003. Information on ikigai was collected by self-reported questionnaire. Data on functional disability were retrieved from the public Long-term Care Insurance database in which participants were followed up for 11 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incidence of functional disability were calculated for three groups delineated according to the presence of ikigai (“no”, “uncertain” or “yes”) using the Cox proportional hazards regression model.

RESULTS

The 11-year incidence of functional disability was 53.3% (442 cases). As compared with the “no” group, the multiple-adjusted HR (95% CI) of incident functional disability was 0.61 (0.36–1.02) for the “uncertain” group and 0.50 (0.30–0.84) for the “yes” group.

CONCLUSION

A stronger degree of ikigai is significantly associated with a lower risk of incident functional disability.

Association between Coffee Consumption and Incident Risk of Disabling Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study

Epidemiological studies of the association between coffee consumption and dementia have yielded inconsistent results. Therefore, we investigated the association between coffee consumption and incident risk of dementia in an elderly Japanese population. 23,091 subjects aged ≥65 y living in Ohsaki City, northeastern Japan, responded to the baseline survey in 2006. Of these, we analyzed 13,137 subjects who gave informed consent and were not disabled at baseline. The outcome was the incidence of disabling dementia defined by usage of the Long-term Care Insurance database. We used the Cox proportional hazards regression model for multivariate analysis. During 5.7 y of follow-up period, we identified 1,107 cases of incident dementia. Overall, coffee consumption was significantly associated with a lower risk of incident dementia. The multivariate-adjusted HRs for the incidence of dementia according to coffee consumption categories (never, occasionally, 1-2 cups/d, and ≥3 cups/d) were 1.00, 0.73 (95% CI, 0.62-0.86), 0.72 (95% CI, 0.61-0.84), and 0.82 (95% CI, 0.65-1.02; p for trend = 0.009), respectively. In addition, this significant inverse association was more remarkable among women, non-smokers, and non-drinkers. Coffee consumption is significantly associated with a lower risk of incident dementia.