Differential Longitudinal Associations Between Domains of Cognitive Function and Physical Function: A 20-Year Follow-Up Study.

OBJECTIVES: Cognitive and physical functions are both associated with disability and death. Recent studies have addressed the relationship between cognitive declines and physical declines; however, whether various facets of cognition are diversely associated with specific physical functions is yet to be ascertained. The present work examines the longitudinal associations between fluid and crystallized cognitive functions (Gf and Gc) and physical functions. METHODS: The sample consisted of 863 community-dwelling older adults (baseline age 60-79 years) from the National Institute for Longevity Sciences-Longitudinal Study of Aging. The participants were tested on a set of Gf and Gc tests and physical tests (grip strength and gait speed). We ran a series of Multivariate Latent Growth Curve models. Specifically, we tested the relationship between cognitive and physical functions in terms of baseline performance (intercept) and rate of change (slope). RESULTS: The slope-slope correlations between Gf and physical function were large (grip strength r = 0.64 and gait speed r = 0.68, ps < .001). By contrast, the slope correlations between Gc and physical functions were weak (rs ≤ 0.31) and barely or marginally significant (ps ≤ .06). DISCUSSION: The results show that distinct domains of cognitive functions have different associations with physical functions. Namely, the aging-associated declines in the tested physical functions are robustly correlated with the declines in Gf, but are only weakly correlated with the declines in Gc. Therefore, Gc measures may be poor proxies for the patient's frailty and should be considered with caution in clinical assessment.

Basal ganglia lesions may be a risk factor for characteristic features of a glaucomatous optic disc: population-based cohort study in Japan.

BACKGROUND: We conducted a study to investigate the relationship between optic nerve vertical cup-to-disc ratio (VCDR), body and ocular parameters, and brain lesions in middle-aged and above Japanese subjects, because although various risk factors for glaucoma have been previously characterised, it is theorised that there are unidentified neurological components. METHODS: In this population-based, age/gender-stratified, cross-sectional study that involved 2239 Japanese subjects (1127 men and 1112 women) aged 40 years and older (mean age: 59.3±11.7 years) living in the central geographical region of Japan who participated in the National Institute of Longevity Sciences-Longitudinal Study of Aging between 2002 and 2004, 4327 eyes and 2239 obtained MRIs of the head were evaluated. Multivariate mixed model and trend analyses were also performed. RESULTS: No significant relationship between VCDR and brain lesions, other than basal ganglia lesions, was found. VCDR significantly increased with the high grade of basal ganglia infarct lesions (p=0.0193) and high intraocular pressure (p<0.0001) after adjustment for influential factors using a multivariate mixed model. A significant positive linear trend was observed between the predicted VCDR and the degrees of the basal ganglia lesions (p value trend=0.0096). CONCLUSION: Our findings suggest that in subjects with higher grades of basal ganglia lesions, strict attention should be paid to elevated VCDR; however, further studies are needed to support/confirm our results.

Twenty-year prospective cohort study of the association between a Japanese dietary pattern and incident dementia: the NILS-LSA project.

PURPOSE: Evidence has suggested that adherence to a Japanese diet may be beneficial for health. However, its association with incident dementia remains unclear. The aim was to explore this association in older Japanese community-dwellers, taking apoprotein E genotype into consideration. METHODS: A 20-year follow-up cohort study involving 1504 dementia-free older Japanese community-dwellers (aged 65-82 years) living in Aichi Prefecture, Japan, was conducted. Based on a previous study, a 9-component-weighted Japanese Diet Index (wJDI9) score (range - 1 to 12) was calculated using 3-day dietary record data and used as an indicator of adherence to a Japanese diet. Incident dementia was confirmed by the Long-term Care Insurance System certificate, and dementia events occurring within the first 5 years of follow-up were excluded. A multivariate-adjusted Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia, and Laplace regression was used to estimate percentile differences (PDs) and 95% CIs (expressed in months) in age at incident dementia (i.e., dementia-free duration differences), according to tertiles (T1-T3) of wJDI9 scores. RESULTS: The median (IQR) follow-up duration was 11.4 (7.8-15.1) years. During the follow-up period, 225 (15.0%) cases of incident dementia were identified. Because the smallest prevalence of incident dementia was 10.7% for the T3 group of wJDI9 scores, to avoid inaccurately estimating the dementia-free duration of participants in the T3 group, the 11th PDs in age at incident dementia between the T1 and T3 groups of wJDI9 scores were estimated. A higher wJDI9 score was associated with a lower risk of incident dementia and a longer dementia-free duration difference. The multivariate-adjusted HR (95% CI) and 11th PDs (95% CI) in age at incident dementia for participants in the T1 vs. T3 group were 1.00 (reference) vs. 0.58 (0.40, 0.86), and 0 (reference) vs. 36.7 (9.9, 63.4) months, respectively. Each 1-point increase of the wJDI9 score was associated with a 5% lower risk of incident dementia (P value = 0.033) and 3.9 (0.3, 7.6) additional months of dementia-free duration (P value = 0.035). No differences were seen in sex or smoking status (current smoker vs. non-current smoker) at baseline. CONCLUSION: These findings suggest that adherence to a Japanese diet defined by wJDI9 is associated with a lower risk of incident dementia in older Japanese community-dwellers, suggesting the benefit of the Japanese diet for dementia prevention.

Association between short-chain fatty acid intake and development of muscle strength loss among community-dwelling older Japanese adults.

BACKGROUND: Short-chain fatty acids (SCFAs) have been suggested to be associated with skeletal muscle mass maintenance. However, the role of dietary SCFAs in preserving muscle strength in the older population remains unclear. OBJECTIVES: To clarify the longitudinal association between the dietary intake of SCFAs and the development of low muscle strength in older community dwellers. METHODS: Data were obtained from the National Institute for Longevity Sciences-Longitudinal Study of Aging cohort. The participants included 441 men and 382 women who participated in the baseline survey (the fifth wave, between 2006 and 2008) and at least one follow-up examination (sixth to ninth waves, between 2008 and 2022) and were ≥60 years old and did not have low muscle strength (defined as a grip strength of <28 kg for men and <18 kg for women) at baseline. Baseline nutrient intakes were assessed with a 3-day dietary record. A generalized estimating equation was employed to estimate the odds ratio (OR) and 95 % confidence intervals (CIs) for low muscle strength per 1 standard deviation (SD) increase in the intake of SCFAs and other nutrients at baseline (adjusted for sex, age, follow-up time, baseline grip strength, physical activity, smoking, family income, education, and disease histories). RESULTS: The mean (SD) follow-up time and number were 7.8 (3.2) years and 3.2 (1.0) times, respectively. Approximately 8.1 % of the participants exhibited muscle strength loss in at least one follow-up assessment. The multivariate-adjusted OR (95 % CIs) was 0.77 (0.63-0.93) for each 1-SD increase in SCFA intake (268 mg/day), and the ORs for the highest through the lowest tertiles of SCFA intake were 1.00 (reference), 1.44 (0.95-2.17), and 1.83 (1.20-2.78), respectively (trend p = 0.005). The results remained significant after multivariate adjusting for energy or fat intake. CONCLUSION: Dietary intake of SCFAs may prevent muscle strength decline in community-dwelling older adults.

Effects of APOEɛ4 genotype on age-associated change in cognitive functions among Japanese middle-aged and older adults: A 20-year follow-up study.

BACKGROUND AND AIMS: Carriers of the apolipoprotein E ε4 allele (APOEɛ4) have an increased risk of developing dementia (e.g., Alzheimer's disease). However, it is less clear whether the APOEɛ4 might also be involved in cognitive aging among the non-clinical population of older adults. While some studies have suggested that the APOEɛ4 is related to accelerated cognitive decline in the normal aging process, others have failed to provide compelling evidence of such an impact. Notably, these discrepancies may depend on methodological shortcomings, including short time spans, few assessments, and small sample sizes. The present study overcomes the above limitations and aims to clarify the impact of the APOEɛ4 genotype on long-term longitudinal changes in cognitive functions in middle-aged and older adults in Japan. METHODS AND RESULTS: The data were retrieved from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) survey (N = 1832; 40 to 79 years of age at baseline). The participants were tested over nine waves covering a period of approximately 20 years. Latent Growth Curve (LGC) modeling was employed to test the impact of the interaction between APOEɛ4 status and age on several cognitive functions. Four tests of the WAIS-R were administered: Information, Similarities, Picture completion, and Digit Symbol Substitution Test (DSST). The results showed that the APOEɛ4 carriers experienced a more pronounced decline in the DSST (p = 0.001) and Similarities (p = 0.022) tests. A similar tendency was found in the Information test (p = 0.034). By contrast, no effect was found in the Picture completion test (p = 0.563). CONCLUSIONS: APOEɛ4 carriers seem to exhibit a steeper cognitive decline, which becomes apparent in old age. This effect is more robust in fluid cognitive skills (DSST) than crystallized cognitive skills (Information and Similarities). Overall, the APOEɛ4 genotype may be a significant risk factor in normal (i.e., non-clinical) cognitive aging.

The association of food intake on the development of hearing impairment after middle age among Japanese community dwellers.

OBJECTIVES: This study aimed to determine whether food intake modifies the risk of developing hearing impairment (HI) in Japanese adults in their 40s. METHODS: Data for individuals who were in their 40s with no HI at baseline and had participated in the survey multiple times were extracted from the National Institute for Longevity Sciences, Longitudinal Study of Aging. A total of 1846 samples observed for up to 11.5 years in 421 participants were included in the analyses. The average 3-day food intake was calculated. HI is defined as a pure-tone average of the better ear at frequencies of 0.5, 1, 2, and 4 kHz greater than 25 dB. The risk of developing HI in the 18 food groups was calculated longitudinally using multivariable cumulative data analyses. RESULTS: Even after adjusting basic confounding factors, food groups, and baseline hearing level, significant associations were found between beverage consumption and risk increments for HI (odds ratio [OR] = 2.374, 95% confidence interval [CI]:1.141-4.940) and also between mushroom intake and risk reduction (OR = 0.215, 95% CI:0.069-0.667). Other foods did not consistently show significant results when the combination of analysis variables were changed. CONCLUSIONS: Although the effect of food on hearing is modest to the extent that the significance varies with the variables used in the analysis, the intake of beverages and mushrooms could potentially modify the risk of developing HI after middle age.

Basic lifestyle habits and volume change in total gray matter among community dwelling middle-aged and older Japanese adults.

The brain controls human behavior, and the gray matter is the main resource of neuronal cells. We examined the longitudinal relationship between six basic lifestyle habits (diet, exercise, sleep, alcohol consumption, smoking, and social activity including employment) and total gray matter volume in community-dwelling adults in Japan. This two-year follow-up study with data derived from the National Institute for Longevity Sciences, Longitudinal Study of Aging, Aichi, Japan, included adults aged 40-87 years (n = 1665, men: 51%). Lifestyle habits were assessed at baseline (2008-2010) using self-reported questionnaires and three-day dietary records. Total gray matter volume at baseline and after two years was estimated using T1-weighted brain magnetic resonance imaging and FreeSurfer software. The association between each lifestyle factor, the total number of healthy lifestyle habits, and gray matter volume change was determined via a multiple linear regression analysis adjusting for baseline age, total gray matter volume, and other confounders. The mean ± standard deviation decrease in total gray matter volume during the two-year follow-up period was 0.94 ± 1.86% in men and 0.61 ± 2.27% in women. In the multiple regression analysis, volume loss in total gray matter positively correlated with male smoking, while it was negatively correlated with male social activity and employment, female dietary diversity, and the total number of healthy lifestyle habits (standardized beta coefficient; -0.061 in men [p = 0.07], -0.113 in women [p < 0.05]). Therefore, engaging in social activities, non-smoking, a diverse diet, or adopting one healthy lifestyle habit may help prevent gray matter volume loss.

Natural History Trajectories of Frailty in Community-Dwelling Older Japanese Adults.

BACKGROUND: The gap between the average life expectancy and healthy life expectancy remains wide. Understanding the natural history of frailty development is necessary to prevent and treat frailty to overcome this gap. This study elucidated the trajectories of 5 frailty assessment components using group-based multitrajectory modeling. METHODS: Overall, 845 community-dwelling older adults (aged 65-91 years; 433 males and 412 females) who underwent longitudinal frailty assessments at least 3 times were included in the analysis. The mean follow-up period (±SD, range) was 7.1 (±2.3, 3.8-11.3) years. In each wave, the physical frailty was assessed for the following 5 partially modified components of the Cardiovascular Health Study criteria: shrinking, weakness, exhaustion, slowness, and low activity. Using group-based multitrajectory modeling, we identified subgroups that followed distinctive trajectories regarding the 5 frailty components. RESULTS: Five frailty trajectory groups were identified: weakness-focused frail progression group (Group 1 [G1]; 10.9%), robust maintenance group (Group 2 [G2]; 43.7%), exhaustion-focused prefrail group (Group 3 [G3]; 24.3%), frail progression group (Group 4 [G4]; 6.7%), and low activity-focused prefrail group (Group 5 [G5]; 14.4%). The Cox proportional hazards model analysis showed that G1, G4, and G5 had significantly higher mortality risks after adjusting for sex and age (G2 was the reference group). CONCLUSION: Based on the natural history of frailty, the 5 distinctive trajectory groups showed that some individuals remained robust, while others remained predominantly prefrail or progressed primarily owing to physical mobility decline. Therefore, identifying individuals belonging to these progressive frailty groups and providing interventions according to the characteristics of each group may be beneficial.

Typology of Work-Family Balance Among Middle-Aged and Older Japanese Adults.

This study explores the clusters of work-family balance (WFB) among Japanese middle-aged and older adults and clarifies the characteristics of the derived clusters. Data on working adults (N = 1,351; age range = 40-85 years) were drawn from a pool of participants in the National Institute for Longevity Sciences-Longitudinal Study of Aging. The WFB scale consists of subscales assessing work-family conflict (WFC) and work-family facilitation (WFF). First, a cluster analysis was performed using the WFB scale, and four clusters were extracted. Second, we examined associations between the four clusters and related variables such as demographic characteristics, work, family, and lifestyle factors, social support, and mental health. Our findings showed that the clusters included high-WFC/high-WFF, high-WFC/low-WFF, low-WFC/high-WFF, and low-WFC/low-WFF. Differences were found in related variables among the clusters. Specifically, those in the Low-WFC/High-WFF cluster had a good lifestyle, received the highest levels of social support, and had the fewest mental health issues. Our findings have implications for maintaining sufficient WFB and promoting positive mental health among workers.

Breakfast Protein Quality and Muscle Strength in Japanese Older Adults: A Community-Based Longitudinal Study.

OBJECTIVES: The amount of breakfast protein intake is important for maintaining muscle strength. However, the effect of breakfast protein quality (ie, bioavailability) remains unclear. We investigated the association between breakfast protein quality and the incidence of muscle weakness. DESIGN: Longitudinal study. SETTING AND PARTICIPANTS: Healthy older adults age 60-83 years without stroke, arthritis, Parkinson disease, or muscle weakness at baseline (maximum follow-up period and participations were 9.2 years and 5 times, respectively). METHODS: Weakness was defined by the Asian Working Group for Sarcopenia 2019 criteria, using grip strength. Breakfast protein quality was evaluated using the protein digestibility-corrected amino acid score (PDCAAS), where higher scores represent higher quality, calculated from 3-day dietary records. Participants were classified according to sex-stratified tertiles of breakfast PDCAAS (ie, low to high groups). The association between PDCAAS and incident weakness was analyzed using the generalized estimating equation, after adjusting for sex, age, follow-up time, grip strength, body mass index, physical activity, cognition, education, smoking, economics, medical history, lunch and dinner PDCAASs, and energy and protein intake during 3 regular meals at baseline. RESULTS: Overall, 14.4% of the initial sample was excluded owing to a diagnosis of weakness-related diseases, and 58.3% (n = 701) had at least 1 follow-up measurement for inclusion in the analysis. The mean ± SD follow-up period was 6.9 ± 2.1 years; the cumulative number of participants was 3019, and 282 developed weakness. Using the low PDCAAS group as the reference, the adjusted odds ratios (95% CIs) for incident weakness in the middle and high PDCAAS groups were 0.71 (0.43-1.18) and 0.50 (0.29-0.86), respectively. CONCLUSIONS AND IMPLICATIONS: Higher breakfast protein quality was associated with a reduction in incident weakness in older adults, independent of protein intake. These findings may highlight the role of protein quality for muscle health in older adults.

Prevalence of usage of hearing aids and its association with cognitive impairment in Japanese community-dwelling elders with hearing loss.

OBJECTIVE: Hearing loss is a risk factor for cognitive impairment, and the use of a hearing aid (HA) may prevent cognitive decline alongside hearing loss. We aimed to elucidate the prevalence of self-reported HA usage in Japanese community-dwelling elders with hearing loss, and the effect of hearing and HA on cognitive impairment. METHODS: A total of 1193 participants, who had audiometric defined hearing loss and were aged 60 years or over, had their cumulative 3260 observations followed up for 10 years from a large cohort of a Japanese study. Association between hearing (pure-tone average threshold level at 500, 1000, 2000, and 4000 Hz from the better hearing ear: PTABHE) and HA usage with cognitive impairment (total score of Mini-Mental State Estimation was under 27 or diagnosed as dementia) was analyzed using generalized estimating equations. RESULTS: The HA usage rate of the 1193 community-dwelling elders with hearing loss was 6% during the first involvement. The majority (59.2%) of HA users always used an HA. HA usage rate was 0.7% for the mild hearing loss group and 32.4% for the moderate or greater hearing loss group in the latest participating wave. PTABHE was significantly associated with cognitive impairment (odds ratio for every 10 dB 1.36; 95% CI 1.21-1.53, p<0.0001) after adjusting for age, sex, education, depressed mood, smoking status, alcohol intake, income, activity, obesity, histories of hypertension, dyslipidemia, ischemic heart disease, diabetes, stroke, ear disease, and occupational noise exposure. PTABHE was also significantly associated with cognitive impairment in the mild hearing loss group (odds ratio for every 10 dB 1.34; 95% CI 1.05-1.72, p = 0.020) and moderate hearing loss group (odds ratio for every 10 dB 1.82; 95% CI 1.27-2.61, p = 0.001). HA use showed a significant suppressive effect on cognitive impairment in those with moderate hearing loss who always use an HA (odds ratio 0.54; 95% CI 0.30-1.00, p = 0.049). CONCLUSION: The prevalence of HA usage among Japanese community-dwelling elders with hearing loss is consistent, at around 10%. The hearing level remained a primary risk factor for cognitive impairment among elders with hearing loss after adjusting for several confounding factors. Regular HA use may have a protective effect on cognitive impairment in those with moderate hearing loss.

Association between intra-individual changes in social network diversity and global cognition in older adults: Does closeness to network members make a difference?

OBJECTIVE: Although qualitative aspects of interpersonal networks, such as diversity or closeness, can protect the health of older adults, their association with cognitive health remains unclear. This study examined the concurrent and time-lagged association between intra-individual changes in global cognition and social network diversity, while considering emotional closeness. METHODS: In this 10-year study, we obtained six-wave, biennial data from the National Institute for Longevity Sciences, Longitudinal Study of Aging. Data from 808 community-dwelling, cognitively intact adults aged 65 or older at baseline were analyzed. Global cognition was assessed using the Mini-Mental State Examination (MMSE). Social network diversity scores were assessed using a social convoy model, comprising three closeness levels: inner (closest), middle (second closest), and outer (least close). RESULTS: The mean age of the respondents was 72.0 ± 4.4 years at baseline, and 50.1% were male. A fixed-effects model showed that intra-individual change in total (coefficients, B: 0.10; standard error [SE]: 0.05; p = .042) and inner (B: 0.25; SE: 0.07; p < .001) social network diversity was significantly associated with MMSE score decline, even after adjusting for covariates. Yet, in time-lagged models, diversity and MMSE score changes were not significantly associated during the subsequent two years. CONCLUSION: Older adults' global cognition declined when the diversity of their closest social network decreased. This may be a promising marker for early cognitive decline in older adults. Indeed, their closest networks are relatively unlikely to decline as part of normal aging or diseases except dementia.

Longitudinal associations between hearing aid usage and cognition in community-dwelling Japanese older adults with moderate hearing loss.

We investigated the associations between hearing aids (HA) and the maintenance of cognitive function among community-dwelling older adults with moderate hearing loss. A total of 407 participants aged 60 years or older with moderate hearing loss were recruited from the National Institute for Longevity Sciences, Longitudinal Study for Aging (NILS-LSA). Moderate hearing loss was defined as a pure-tone average of 40-69 dB at 500, 1000, 2000, and 4000 Hz of the better ear, according to the definition proposed by the Japan Audiological Society. Cognitive function was evaluated using the four subtests of the Japanese version of the Wechsler Adult Intelligence Scale-Revised Short Forms (WAIS-R-SF): Information, Similarities, Picture completion, and Digit Symbol Substitution (DSST). A longitudinal analysis of 1192 observations with a mean follow-up period of 4.5 ± 3.9 years was performed. The HA use rate at any time during the follow-up period was 31.4%, and HA users were significantly younger (t-test, p = 0.001), had worse hearing (p < .0001) and higher education (p = 0.001), participated more frequently in the survey (p < .0001), and were less depressed (χ2 test, p = 0.003) than the older adults not using HA. General linear mixed models consisted of the fixed effects of HA use, follow-up time, and an HA use × time interaction term adjusted for age and pure-tone average thresholds at baseline, sex, education, and other possible confounders. HA use showed significant main effects on the scores for Picture completion and DSST after adjustment; scores were better in the HA use group than in the no HA use group. The HA use × time interaction was significant for the Information score (p = 0.040). The model-predicted 12-year slope with centralizing age indicated that the no HA use group showed greater decline over time on Information scores than did HA use group. The slopes did not differ between HA users and non-users for the Similarities, Picture completion and DSST. In conclusion, HA use may have a protective effect on the decline in general knowledge in older adults with moderate hearing loss.

Interaction between cognitive leisure activity and long-chain polyunsaturated fatty acid intake on global cognitive decline in a Japanese longitudinal cohort study: National Institute for Longevity Sciences-Longitudinal Study of Aging.

BACKGROUND: There is a growing interest in the significance of adopting a variety of lifestyle habits for maintaining cognitive function among older adults. A lifestyle that is easy to modify, simple, and less burdensome for older people is ideal. We investigated the longitudinal association between global cognitive decline and cognitive leisure activities (CLAs) combined with long-chain polyunsaturated fatty acids (LCPUFAs) intake. METHODS: The National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) enrolled community-dwelling middle-aged and older men and women who were randomly selected from Obu-City and Higashiura Town, Aichi, Japan. Baseline data (2006-2008), including CLAs and dietary intake, were obtained from 517 participants (aged 60-84 years) with normal cognition. Global cognitive decline, defined as the Mini-Mental State Examination (MMSE) score ≤ 27, was assessed at baseline and four years later. Interaction between CLAs and LCPUFAs on cognitive decline was investigated using a multiple logistic analysis with adjustment for confounders. CLA engagement and LCPUFA intake were divided into high and low groups according to the frequency at which each participant engaged in the activity and the median intake level according to sex, respectively. RESULTS: A significant interaction was detected for the combination of CLA engagement and LCPUFA intake. Logistic regression coefficients revealed significant interactions when participants engaged in more than five CLA varieties. One of the CLAs, art appreciation, produced a significant main effect against cognitive decline and a significant interaction in combination with LCPUFA intake. The major LCPUFAs-docosahexaenoic acid and arachidonic acid-also exhibited a significant interaction. The combination of high LCPUFA intake and high art appreciation frequency yielded a lower adjusted odds ratio for cognitive decline than the combination of low LCPUFA and low art appreciation [0.25 (95 % confidence intervals, 0.11-0.56)]. CONCLUSIONS: Preserving cognitive function might be associated with a combination of varied and high-frequency engagement in CLAs combined with high LCPUFA intake.

Green tea consumption is associated with annual changes in hippocampal volumes: A longitudinal study in community-dwelling middle-aged and older Japanese individuals.

BACKGROUND: To investigate the association between green tea consumption and the annual rate of change of gray matter (GM), white matter (WM), and hippocampal volumes in community-dwelling middle-aged and older Japanese individuals. METHODS: A prospective cohort study with two years of follow-up was conducted as part of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) project. A total of 1693 participants (862 men and 831 women, aged 40-89 years) were included. Green tea consumption (mL/day) data were collected with a 3-day dietary record. Volumes of GM, WM, and the hippocampus were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. The GM ratio, WM ratio, and hippocampal ratio (HR) were calculated as the percentages of total intracranial volume, respectively. RESULTS: The mean (SD) annual rate of change of hippocampal volume [(HR at baseline - HR at follow-up)/HR at baseline/follow-up years×100%] was 0.499 (1.128) (%). In the multivariable-adjusted general linear model, green tea consumption was negatively associated only with the annual rate of change of hippocampal volume (%) [ß (95% CI) for each 1 mL/day increase in green tea consumption = -20.2E-5 (-35.0E-5 to -5.3E-5); P-value = 0.008]. No associations were observed for the annual rate of change of GM or WM volumes. The results remained significant when the analysis was limited to those with stable green tea consumption and were especially evident among individuals aged 65 years and older and among women. CONCLUSIONS: In this study, higher green tea consumption was associated with less annual hippocampal atrophy, and each additional 100 mL/day of green tea intake was related to a reduction of approximately 5% in annual hippocampal atrophy. This association was especially evident among older individuals and among women. Further study in different settings is needed to confirm this association.

Intake of isoflavones reduces the risk of all-cause mortality in middle-aged Japanese.

BACKGROUND/OBJECTIVES: To clarify the effects of intake of legumes and isoflavones on all-cause mortality in middle-aged and older Japanese. SUBJECT/METHODS: The subjects were 2136 randomly chosen community-dwelling Japanese men and women aged 40-79 years who participated in a first-wave survey (1997-2000; baseline). The subjects were followed from baseline to December 31, 2017 (mean period of 16.6 ± 4.2 years). Intake of legumes, soybeans, and isoflavones at baseline was assessed using a 3-day dietary record with photographs. The relationships of intake amounts of legumes and isoflavones to mortality were assessed using Cox proportional hazards regression controlling for age, sex, education, employment, body mass index, smoking habits, medical histories, drinking, and energy intake. RESULTS: There were 491 deaths during the follow-up period. We found inverse associations of the intake of total soy products and intake of each of the isoflavones with all-cause mortality (p for trend < 0.05) in subjects aged < 60 years: the multivariate-adjusted hazard ratios (95% confidence intervals) for all-cause mortality in the highest intake group (third tertile) of total soy products and total isoflavones were 0.32 (0.13-0.78) and 0.35 (0.17-0.73), respectively, compared with the reference group (first tertile). In contrast, there were no significant associations of intake amounts of legumes, soybeans, and isoflavones with all-cause mortality in subjects aged 60 years or older. CONCLUSIONS: The findings suggest that a higher intake of isoflavones might decrease the risk of all-cause mortality, especially in middle-aged Japanese.

Dietary diversity is associated with longitudinal changes in hippocampal volume among Japanese community dwellers.

BACKGROUND/OBJECTIVES: Dietary habits are known to affect health, including the rate of brain ageing and susceptibility to diseases. This study examines the longitudinal relationship between dietary diversity and hippocampal volume, which is a key structure of memory processing and is known to be impaired in dementia. SUBJECTS/METHODS: Subjects were aged 40-89 years (n = 1683, men: 50.6%) and participated in a 2-year follow-up study of the National Institute for Longevity Sciences-Longitudinal Study of Aging. Dietary intake was calculated from 3-day dietary records, and dietary diversity was determined using the Quantitative Index for Dietary Diversity at baseline. Longitudinal changes in hippocampal and total grey matter volumes were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. Estimated mean brain volume change in relation to dietary diversity score quintiles was assessed by the general linear model, adjusted for age, sex, education, smoking status, alcohol intake, physical activity, and comorbidities. RESULTS: The mean (± standard deviation) % decreases in hippocampal and total grey matter volume during the 2-year follow-up were 1.00% (±2.27%) and 0.78% (±1.83%), respectively. Multivariate-adjusted decreases in total grey matter volume were associated with dietary diversity score (p = 0.065, p for trend = 0.017), and the % decrease in hippocampal volume was more strongly associated with the dietary diversity score: the estimated mean (± standard error) values were 1.31% (±0.12%), 1.07% (±0.12%), 0.98% (±0.12%), 0.81% (±0.12%), and 0.85% (±0.12%), according to dietary diversity quintiles in ascending order (p = 0.030, p for trend = 0.003). CONCLUSIONS: Among community dwellers, increased dietary diversity may be a new nutritional strategy to prevent hippocampal atrophy.

Dietary Diversity and All-Cause and Cause-Specific Mortality in Japanese Community-Dwelling Older Adults.

We examined associations between dietary diversity and all-cause and cause-specific mortality in 386 men and 413 women (age range, 60-79 years at baseline) who took part in the National Institute for Longevity Sciences-Longitudinal Study of Aging study from 1997 to 2000. Dietary intake was assessed using three-day dietary records and photographs. The Quantitative Index for Dietary Diversity was used to determine the dietary diversity among thirteen food groups. Dietary diversity score and each food intake were examined by sex-stratified tertiles, and hazard ratios (HR) were calculated to compare the risk for all-cause and cause-specific deaths across tertiles, after controlling for age, sex, body mass index, alcohol intake, smoking status, education, physical activity, and disease history. During a mean follow-up of 15.7 years, 289 subjects (36.2%) died. Compared to the subjects in the lowest tertile, the multivariate-adjusted HR for all-cause and cancer mortality was 0.69 (95% confidence interval (CI): 0.51-0.94) and 0.57 (95% CI: 0.33-0.98), respectively (trend p < 0.05), in subjects in the highest tertile of dietary diversity. There were no significant associations between dietary diversity score and death from cardiovascular or cerebrovascular disease. Eating a variety of foods might contribute to longevity in older Japanese community dwellers.

Age-Related Changes in Physical Fitness Among Community-Living Middle-Aged and Older Japanese: A 12-Year Longitudinal Study.

Physical fitness is one of the key factors in healthy aging. Although physical fitness is widely recognized to decline with age, age-related decreases in the individual dimensions of physical fitness in later life are less clear. Purpose: The purpose of the present study was to describe the age-related changes in six fitness components covering a variety of motor dimensions in men and women through a 12-year longitudinal epidemiological study. Method: Participants were randomly selected community-living men (n = 1,139) and women (n = 1,128) aged 40 to 79 years at baseline who were repeatedly tested over a mean (standard deviation) follow-up period of 9.8 (3.4) years with a mean of 4.9 (2.3) examinations. The six physical fitness tests were sit-and-reach, grip strength, sit-ups, one-leg standing, reaction time and leg extension power. The effect of age on each physical fitness task was analyzed using a mixed-effects model controlling for habitual physical activity level. Results: The fixed effect of the interaction of age and time in all fitness tests was significant in men. Higher age at baseline was significantly associated with a greater decrease over time except in one-leg standing. In women, no significant interaction effect of age and time was found in grip strength or reaction time. Age-related changes in grip strength and reaction time were constant with increasing age. Conclusion: Twelve-year longitudinal data showed that the age-related decrease in physical fitness over time, especially musculoskeletal fitness in men, was pronounced, whereas in women, the decrease was less pronounced.

Green tea and coffee intake and risk of cognitive decline in older adults: the National Institute for Longevity Sciences, Longitudinal Study of Aging.

OBJECTIVE: To examine the association between green tea and coffee intake and cognitive decline in older adults. DESIGN: A prospective cohort study. The average intake of green tea and coffee in the previous year was assessed through a dietitian interview using a dietary questionnaire. A Mini-Mental State Examination (MMSE) was conducted up to six times biennially. Cognitive decline was screened using the MMSE; its incidence was defined as the first time a score of <27 points was obtained in a biennial test from the baseline. Hazard ratios for incidence of cognitive decline were estimated according to the intake of the two beverages using multivariable Cox proportional hazard regression, controlling for sociodemographic and lifestyle factors. SETTING: The National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA) in Japan. PARTICIPANTS: Men (n 620) and women (n 685), aged 60-85 years, from the NILS-LSA. RESULTS: During a mean of 5·3 (sd 2·9) years of follow-up, 432 incident cases of cognitive decline were observed. Compared with participants who consumed green tea