Associations of dietary patterns and longitudinal brain-volume change in Japanese community-dwelling adults: results from the national institute for longevity sciences-longitudinal study of aging.

BACKGROUND: The association of dietary patterns and longitudinal changes in brain volume has rarely been investigated in Japanese individuals. We prospectively investigated this association in middle-aged and older Japanese community-dwelling adults. METHODS: Data with a 2-year follow-up from the sixth wave (July 2008 to July 2010; baseline) to the seventh (July 2010 to July 2012; follow-up) of the National Institute for Longevity Sciences-Longitudinal Study of Aging project were analyzed. Dietary intake was assessed using a 3-day dietary record, and longitudinal volume changes (%) in the total gray matter (TGM), total white matter, and frontal, parietal, occipital, temporal, and insular lobes were assessed using 3-dimensional T1 magnetic resonance imaging scans. Multiple factor analysis and hierarchical clustering revealed sex-specific dietary patterns. Associations between dietary patterns and annual brain-volume changes (%) were evaluated using general linear models adjusted for age, apoprotein E genotype, body mass index, medical history, lifestyle behaviors, socioeconomic factors, and energy intake. RESULTS: Among the 1636 participants (age: 40.3-89.2 years), three dietary patterns were determined for men (n = 815; Western; Vegetable-Fruit-Dairy; and Traditional Japanese diets) and women (n = 821; Western; Grain-Vegetable-Fruit; and Traditional Japanese diets). Compared to women following the Western diet, those on the Traditional Japanese diet had less TGM atrophy. Multivariable-adjusted ß (95% confidence interval) of the annual change (%) of TGM was - 0.145 (-0.287 to -0.002; P = 0.047), which correlated with reduced parietal lobe atrophy. No association between dietary pattern and brain atrophy was observed in men. CONCLUSIONS: Adherence to healthy dietary patterns, with higher consumption of whole grains, seafood, vegetables, fruits, mushrooms, soybean products, and green tea, potentially confers a protective effect against brain atrophy in middle-aged and older Japanese women but not in men. Further research to confirm these results and ascertain the underlying mechanisms is required. This study highlights the importance of sex-specific effects on the relationship between dietary patterns and brain health in diverse populations.

Traditional japanese diet score and the sustainable development goals by a global comparative ecological study.

BACKGROUND: Reducing the environmental impact of the food supply is important for achieving Sustainable Development Goals (SDGs) worldwide. Previously, we developed the Traditional Japanese Diet Score (TJDS) and reported in a global ecological study that the Japanese diet is associated with reducing obesity and extending healthy life expectancy etc. We then examined the relationship between the TJDS and environmental indicators. METHODS: The average food (g/day/capita) and energy supplies (kcal/day/capita) by country were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database. The TJDS was calculated from eight food groups (beneficial food components in the Japanese diet: rice, fish, soybeans, vegetables, and eggs; food components that are relatively unused in the traditional Japanese diet: wheat, milk, and red meat) by country using tertiles, and calculated the total score from - 8 to 8, with higher scores meaning greater adherence to the TJDS. We used Land Use (m2), Greenhouse gas (GHG) emissions 2007/2013 (kg CO2eq), Acidifying emissions (g SO2eq), Eutrophying emissions (g PO43- eq), Freshwater (L), and water use (L) per food weight by Poore et al. as the environmental indicators and multiplied these indicators by each country's average food supply. We evaluated the cross-sectional and longitudinal associations between the TJDS and environmental indicators from 2010 to 2020. This study included 151 countries with populations ≥ 1 million. RESULTS: Land use (ß ± standard error; -0.623 ± 0.161, p < 0.001), GHG 2007 (-0.149 ± 0.057, p < 0.05), GHG 2013 (-0.183 ± 0.066, p < 0.01), Acidifying (-1.111 ± 0.369, p < 0.01), and Water use (-405.903 ± 101.416, p < 0.001) were negatively associated with TJDS, and Freshwater (45.116 ± 7.866, p < 0.001) was positively associated with TJDS after controlling for energy supply and latitude in 2010. In the longitudinal analysis, Land Use (ß ± standard error; -0.116 ± 0.027, p < 0.001), GHG 2007 (-0.040 ± 0.010, p < 0.001), GHG 2013 (-0.048 ± 0.011, p < 0.001), Acidifying (-0.280 ± 0.064, p < 0.001), Eutrophying (-0.132 ± 0.062, p < 0.05), and Water use (-118.246 ± 22.826, p < 0.001) were negatively associated with TJDS after controlling for confounders. CONCLUSIONS: This ecological study suggests that the traditional Japanese dietary pattern might improve SDGs except Fresh water.

No Appreciable Effect of Education on Aging-Associated Declines in Cognition: A 20-Year Follow-Up Study.

Education has been claimed to reduce aging-associated declines in cognitive function. Given its societal relevance, considerable resources have been devoted to this research. However, because of the difficulty of detecting modest rates of change, findings have been mixed. These discrepancies may stem from methodological shortcomings such as short time spans, few waves, and small samples. The present study overcame these limitations (N = 1,892, nine waves over a period of 20 years). We tested the effect of education level on baseline performance (intercept) and the rate of change (slope) in crystallized and fluid cognitive abilities (gc and gf, respectively) in a sample of Japanese adults. Albeit positively related to both intercepts, education had no impact on either the gc or the gf slope. Furthermore, neither intercept exhibited any appreciable correlation with either slope. These results thus suggest that education has no substantial role (direct or mediated) in aging-related changes in cognition.

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.

Dietary amino acid intake and sleep duration are additively involved in future cognitive decline in Japanese adults aged 60 years or over: a community-based longitudinal study.

BACKGROUND: Sleep duration and amino acid intake are independently associated with cognitive decline. This study aimed to determine the longitudinal association between sleep duration and cognitive impairment incidence and to examine the involvement of diet, particularly amino acid intake, in these associations in community dwellers. METHODS: In this longitudinal study in a community-based setting, we analyzed data from 623 adults aged 60-83 years without cognitive impairment at baseline. Sleep duration was assessed using a self-report questionnaire. Amino acid intake was assessed using 3-day dietary records. Cognitive impairment was defined as a Mini-Mental State Examination score ≤ 27. Participants were classified into short-, moderate-, and long-sleep groups according to baseline sleep duration (≤ 6, 7-8, and > 8 h, respectively). Using moderate sleep as a reference, odds ratios (ORs) and 95% confidence intervals (CIs) of short- and long-sleep for cognitive-impairment incidence were estimated using the generalized estimating equation. Participants were classified according to sex-stratified quartiles (Q) of 19 amino acid intake: Q1 and Q2-Q4 were low- and middle to high-intake groups, respectively. Using middle- to high-intake as a reference, ORs and 95% CIs of low intake for cognitive impairment incidence were estimated using the generalized estimating equation in each sleep-duration group. Follow-up period, sex, age, body mass index, depressive symptoms, education, smoking status, employment status, sleep aids use, physical activity, medical history, and Mini-Mental State Examination score at baseline were covariates. RESULTS: Mean follow-up period was 6.9 ± 2.1 years. Adjusted ORs (95% CIs) for cognitive impairment in short- and long-sleep groups were 0.81 (0.49-1.35, P = 0.423) and 1.41 (1.05-1.87, P = 0.020), respectively. Particularly in long sleepers (i.e., > 8 h), cognitive impairment was significantly associated with low cystine, proline, and serine intake [adjusted ORs (95% CIs) for cognitive impairment were 2.17 (1.15-4.11, P = 0.017), 1.86 (1.07-3.23, P = 0.027), and 2.21 (1.14-4.29, P = 0.019), respectively]. CONCLUSIONS: Community-dwelling adults aged ≥ 60 years who sleep longer are more likely to have cognitive decline, and attention should be paid to the low cystine, proline, and serine intake.

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.

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.

Global relationship between Mediterranean diet and the incidence and mortality of ischaemic heart disease.

BACKGROUND: The purpose of this study was to clarify the global relationship between the Mediterranean diet score (MDS) and country-wise incidence and mortality of ischaemic heart disease (IHD) using an international database. METHODS: We used population data from a global longitudinal database covering 137 countries with a population of over one million. MDS were evaluated based on the total score of the nine foods that comprise the Mediterranean diet. The incidence and mortality of IHD by country was derived from the Global Burden of Disease (GBD) database. Average food (g/day/capita) and energy supply (kcal/day/capita) by country, excluding loss between production and household, were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database. Data from the GBD database were used for body mass index, current smoking rates, physical activity, years of education and percentage of the Muslim population. We identified the percentage of the population over 65 years of age (aging rate) and gross domestic product per capita (US$/capita) using the World Bank database. A linear mixed-effect model was used for evaluating the effects of MDS on incidence and mortality of IHD controlled for socioeconomic and lifestyle variables. RESULTS: Analysis showed that MDS was significantly associated with IHD incidence after controlling for covariates (-1.01 ± 0.27, P < 0.001). Similarly, there was a significant association between MDS and IHD-related mortality after controlling for covariates (-0.73 ± 0.34, P < 0.05). CONCLUSION: Analysis of 27 years of data suggests that a Mediterranean diet might have a preventive effect on IHD.

Vasomotor symptoms, sleep problems, and depressive symptoms in community-dwelling Japanese women.

AIM: To assess prevalence and characteristics of vasomotor symptoms in community-dwelling Japanese women. METHODS: These were cross-sectional analyses using data from the National Institute for Longevity Sciences-Longitudinal Study of Aging. The main outcome measures were prevalence and severity of hot flashes and sweating. Associations between hot flashes/sweating (slight, moderate, or severe vs none) and sleep problems were explored using logistic regression, with and without adjustment for age, daily physical activity, and number of urinations/night. Associations between hot flashes/sweating and sleep problems, depressive symptoms, and dietary variables were explored in logistic regression models or general linear models. RESULTS: A total of 1152 women between 40 and 91 years of age were enrolled. Hot flashes were reported by 24.5% of participants; with prevalence and severity highest in those 50-54 years or 2-5 years postmenopause. Sleep problems were reported 15 percentage points more frequently by women who reported hot flashes than by those without hot flashes. Adjusted odds ratios [95% CI] for difficulty in falling asleep and difficulty in sleeping through were 2.09 [1.565-2.796] and 2.07 [1.549-2.763]), respectively. Also, hot flashes were associated with higher risk of depressive symptoms (adjusted odds ratio [95% CI]: 2.99 [2.07-4.32]) and lower life satisfaction, self-esteem, and self-rated health status. A similar pattern was observed in women with and without sweating. No associations were found between hot flashes and dietary factors. CONCLUSIONS: Clear associations were found between hot flashes and sleeping problems, even after adjusting for potential confounding factors. Women who reported hot flashes also reported worse mental and physical health than those who did not report hot flashes.

[Cross-sectional association between the amino acid intake and episodic memory in middle- and old-aged community dwellers].

AIM: The specific amino acid intake has been suggested to be positively associated with the cognitive function. However, few reports have investigated the association between the amino acid intake and episodic memory (EM). Therefore, we investigated this association. METHODS: Data were obtained from the fourth survey (2004-2006) of the National Institute for Longevity Sciences - Longitudinal Study of Aging. We analyzed 2,082 participants 40-85 years old (50.1% male). The dietary intake was assessed by the three-day dietary records, and participants were classified into sex- and age-specific tertiles of protein and amino acid intakes. EM was assessed using the Logical Memory II of the Wechsler Memory Scale. The association of protein and amino acid intakes with EM was analyzed using the general linear model. Covariates were sex, age, body mass index, education, depressive symptoms, smoking status, employment status, living alone, and medical history in model 1. The energy intake was added to model 1 in model 2. The protein intake was added to model 2 in model 3. RESULTS: The mean (standard deviation) age was 59.4 (12.3) years old. After adjusting for the energy intake, the EM tended to be higher with a higher protein intake (p=0.053 for group differences and p=0.015 for trends). Furthermore, after adjusting for energy and protein intake, EM was significantly higher with higher intakes of isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine, tryptophan, valine, and histidine (p< 0.05, both for group differences and trends). CONCLUSION: Our findings suggest a positive association between EM and the intake of essential and semi-essential amino acids, independent of the protein and energy intake.

A clinical dose of angiotensin-converting enzyme (ACE) inhibitor and heterozygous ACE deletion exacerbate Alzheimer's disease pathology in mice.

Inhibition of angiotensin-converting enzyme (ACE) is a strategy used worldwide for managing hypertension. In addition to converting angiotensin I to angiotensin II, ACE also converts neurotoxic ß-amyloid protein 42 (Aß42) to Aß40. Because of its neurotoxicity, Aß42 is believed to play a causative role in the development of Alzheimer's disease (AD), whereas Aß40 has neuroprotective effects against Aß42 aggregation and also against metal-induced oxidative damage. Whether ACE inhibition enhances Aß42 aggregation or impairs human cognitive ability are very important issues for preventing AD onset and for optimal hypertension management. In an 8-year longitudinal study, we found here that the mean intelligence quotient of male, but not female, hypertensive patients taking ACE inhibitors declined more rapidly than that of others taking no ACE inhibitors. Moreover, the sera of all AD patients exhibited a decrease in Aß42-to-Aß40-converting activity compared with sera from age-matched healthy individuals. Using human amyloid precursor protein transgenic mice, we found that a clinical dose of an ACE inhibitor was sufficient to increase brain amyloid deposition. We also generated human amyloid precursor protein/ACE+/- mice and found that a decrease in ACE levels promoted Aß42 deposition and increased the number of apoptotic neurons. These results suggest that inhibition of ACE activity is a risk factor for impaired human cognition and for triggering AD onset.

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

Protein intake per day and at each daily meal and skeletal muscle mass declines among older community dwellers in Japan.

OBJECTIVE: To examine associations between protein intake per day and at different meals and skeletal muscle mass declines. DESIGN: Two-year prospective cohort study among older community dwellers. SETTING: National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) in Japan. PARTICIPANTS: Older men (n 292) and women (n 363) aged 60-87 years who participated in the baseline (2006-2008) and follow-up studies (2008-2010) of NILS-LSA and did not exhibit low skeletal muscle mass at baseline. Muscle mass was assessed using dual-energy X-ray absorptiometry at baseline and follow-up. Low muscle mass was defined as skeletal muscle mass index <7·0 kg/m2 for men and <5·4 kg/m2 for women at follow-up. Daily protein intake and protein intake at each meal were calculated from 3 d dietary records at baseline and sex-stratified tertiles were determined. RESULTS: Mean (sd) protein intake at breakfast, lunch and dinner was 22·7 (7·8), 26·7 (9·3) and 37·4 (10·5) g for men and 19·3 (6·3), 23·2 (7·3) and 28·5 (7·0) g for women, respectively. After adjusting for age, baseline skeletal muscle mass and other confounders in logistic modelling, greater total protein intake was associated with lower prevalence of skeletal muscle mass decline among men at follow-up (P = 0·024). Particularly, the OR (95 % CI) for high lunchtime protein intake was low (0·11 (0·02, 0·61); P = 0·01). No significant association between total protein intake and prevalence of skeletal muscle mass decline was found among women. CONCLUSIONS: High total protein intake, particularly at lunchtime, is associated with retention of skeletal muscle mass in men.

Association between physical function and long-term care in community-dwelling older and oldest people: the SONIC study.

BACKGROUND: Preventing the need for long-term care (LTC) by identifying physical function risk factors are important to decrease the LTC burden. The objective of this study was to investigate whether grip strength and/or walking speed, which are components of the frailty definition, are associated with LTC in community-dwelling older and oldest people. METHODS: The participants were 1098 community-dwelling older and oldest people who had not received LTC at the baseline. The endpoint was receiving LTC after the baseline survey. The independent variables were grip strength and walking speed, and participants were divided into two groups based on these variables. The confounding factors were age, sex, the Japanese version of the Montreal Cognitive Assessment (MoCA-J), hypertension, diabetes mellitus, stroke, joint diseases, living alone, body mass index, and serum albumin. We calculated the hazard ratio of receiving LTC using the Cox proportional hazard model. RESULTS: Among the 1098 participants, 107 (9.7%) newly received LTC during the follow-up. Regarding the physical function, only slow walking speed was significantly correlated with LTC after adjusting for all confounding factors except the MoCA-J score (HR = 1.74, 95% CI = 1.10-2.75, P = .018). However, slow walking speed was still a risk factor for LTC after adjusting for the MoCA-J score and other confounding factors (HR = 1.64, 95% CI = 1.03-2.60, P = .037). CONCLUSIONS: The findings from this study may contribute to a better understanding of slow walking speed as a factor related to LTC, which might be a criterion for disability prevention and could serve as an outcome measure for physical function in older people.

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.

Mediterranean diet score and incidence of IHD: a global comparative study.

OBJECTIVE: The aim of the present study was to clarify the global relationship between Mediterranean diet score (MDS) and the incidence of IHD by country using international statistics. DESIGN: The incidence of IHD by country was derived from the Global Burden of Disease (GBD) database. Average supplies of food (g/d per capita) and energy (kcal/d per capita) by country, excluding loss between production and household, were obtained from the FAOSTAT database. MDS was evaluated based on the total score of nine food items that characterize the Mediterranean diet. The association between MDS and the incidence of IHD was examined in countries with a population of 1 million or greater using a general linear model controlled for socio-economic and lifestyle variables. SETTING: Population data from global international databases.ParticipantsOne hundred and thirty-two countries with a population of over 1 million. RESULTS: MDS was inversely correlated with obesity rate, ageing rate, years of education and IHD incidence; however, no associations were found with gross domestic product, life expectancy, smoking rate, energy supply or health expenditure. In the general linear model of IHD incidence by MDS controlled for socio-economic and lifestyle variables, the ß of the MDS was -26·4 (se 8·6; P<0·01). CONCLUSIONS: The results of this global international comparative study confirmed that the Mediterranean diet is inversely associated with the incidence of IHD.

Role of gait speed and grip strength in predicting 10-year cognitive decline among community-dwelling older people.

BACKGROUND: The gait speed and handgrip strength represented the core determinants of physical frailty and sarcopenia, which were reported to be associated with cognitive impairment and decline. Different physical measures might differentially affect cognitive changes, such as higher-level cognitive change and global cognitive decline. This study examined the differential associations of gait speed and handgrip strength with 10-year cognitive changes among community-dwelling older people. METHODS: Participants aged 60 years and over living in the community were invited for study. Gait speed and handgrip strength were classified into 5 groups based on quintiles at baseline. Cognitive functions were assessed using the Mini-Mental State Examination (MMSE) and Digit Symbol Substitution Test (DSST) every 2 years from baseline for a period of 10 years. Linear mixed effects models were used to determine the role of gait speed and handgrip strength in the prediction of 10-year cognitive changes by adjusting covariates, including age, gender, education, depressive symptoms, marital status, smoking status, instrumental activities of daily life (IADL), Charlson Comorbidity Index (CCI), and body mass index (BMI) at baseline. RESULTS: A total of 1096 participants were enrolled in the study. The mean age was 69.4 ± 5.8 years and 50.9% were male. The slowest gait speed group showed a significantly greater decline in the DSST scores over 10 years than the highest group (estimate = 0.28 and P = 0.003), but not in the MMSE scores (estimate = 0.05 and P = 0.078). The lowest handgrip strength group showed a significantly greater decline in the MMSE scores than the highest group (estimate = 0.06 and P = 0.039) and in the DSST scores than the highest two quintiles (estimate = 0.20 and P = 0.033 for the fourth quintile; estimate = 0.20 and P = 0.040 for the highest quintile) over 10-year follow-up. CONCLUSIONS: A slow gait speed could predict 10-year cognitive decline using DSST, and a low handgrip strength could predict 10-year cognitive decline using MMSE in addition to DSST. Thus both physical measures are lined to cognitive decline but there may be different mechanisms between brain and physical functions.

Hemoglobin A1c and 10-year information processing speed in Japanese community dwellers.

BACKGROUND: Hyperglycemia is believed to be a risk factor for cognitive decline, but the longitudinal relationship between hyperglycemia and cognitive decline in the Japanese population is unclear. The present study aimed to clarify the association between blood glucose levels and information processing ability in middle-aged and older adults. METHODS: The subjects were 866 men and 815 women aged 40-79 years not taking medication for diabetes who participated in the first study wave (1997-2000) and then participated at least once in the subsequent six study waves (2000-2012) of the National Institute for Longevity Sciences-Longitudinal Study of Aging, Japan. Hemoglobin A1c (HbA1c) levels were categorized into four groups (< 5.6, 5.6 to < 6.0, 6.0 to < 6.5, ≥ 6.5%), and a mixed-effects model was used to evaluate the effects of the HbA1c level (four groups) on repeated measures of information processing speed. The models also included baseline age, body mass index, ethanol intake, smoking status, educational level, family income, and history of stroke, hypertension, heart disease, and dyslipidemia as covariates. RESULTS: Mean (standard deviation) HbA1c and follow-up time in participants were 5.2 (0.5) % and 10.0 (3.6) years, respectively. A linear mixed model showed that the main effect of the four HbA1c groups on information processing ability was not significant in either men or women, but the interaction of HbA1c and time with information processing speed in the higher HbA1c level groups (≥ 6.5% group in men, 6.0 to < 6.5% and ≥ 6.5% groups in women) was significant compared to the lower HbA1c level (< 5.6%) group (P < 0.05). When the slope of information processing speed by HbA1c level at baseline was examined, the slope of information processing speed in the higher HbA1c level (≥ 6.5%) group was higher than in the lower HbA1c level (< 5.6%) group, both in men (- 0.31/year) and in women (- 0.30/year), as well as in women with an HbA1c level of 6.0 to < 6.5% (- 0.40/year). CONCLUSIONS: Higher baseline HbA1c was associated with greater subsequent decline in information processing ability in Japanese community dwellers, even with the pre-clinical HbA1c level (6.0 to < 6.5%) in women. The results suggest that good glycemic control or prevention of hyperglycemia may contribute to maintaining information processing ability.

What is the best adjustment of appendicular lean mass for predicting mortality or disability among Japanese community dwellers?

BACKGROUND: Age-related declines in skeletal muscle mass and strength, representing "sarcopenia," are a growing concern in aging societies. However, the prevalence of low muscle mass based on the height2-adjustment has been shown to be extremely low, and a more appropriate definition of low muscle mass is needed, particularly for Asian women. The aim of this study was to explore the most appropriate adjustment of appendicular lean mass (ALM) for predicting mortality or disability risk using ALM or any of 5 adjustments of ALM among community-dwelling Japanese. METHODS: Subjects comprised 1026 men and 952 women between 40 and 79 years old at baseline (1997-2000) who participated in the National Institute for Longevity Sciences - Longitudinal Study of Aging, Japan. ALM (kg) and 5 adjusted indices of ALM (ALM/leg length, ALM/height, ALM/height2, ALM/weight, and ALM/body mass index [BMI]) were assessed at baseline. Disability was defined by long-term care insurance certification based on responses to a survey mailed in 2013, and death records were obtained as vital statistics until December 2014. Crude and adjusted Cox proportional hazard models were used to estimate hazard ratios for mortality or disability by sex-stratified quintiles of each ALM index (ALM and adjusted ALM) or sarcopenia-related indices. The area under the curve (AUC) was calculated with the multivariate-adjusted logistic regression model. Additionally, mixed-effects analyses were used to clarify the age-related ALM indices decline over 12 years (n = 1838). RESULTS: Crude Cox proportional hazard models and multivariate-adjusted logistic model (AUC) indicated that higher ALM and ALM/BMI in women, and higher ALM, ALM/leg length, ALM/height, and ALM/BMI in men were associated with lower risks for mortality or disability than ALM/height2. The mixed effect model indicated all ALM indices in men, and ALM, ALM/leg length, and ALM/height in women could better predict age-related lean muscle mass decline. CONCLUSIONS: Unadjusted ALM in women, and ALM/leg length, ALM/height, ALM/BMI, and ALM in men may be more appropriate for predicting future mortality or disability than ALM/height2. Considering the age-related muscle mass decline, unadjusted ALM would be the first variable to assess, regardless of sex, in this Japanese cohort study.

[Aging-related frailty and sarcopenia. Epidemiology of Frailty and Sarcopenia.]

Frailty and sarcopenia present significant risks for adverse outcomes such as disability, falls, and mortality in Japanese older adults. Among community-dwelling Japanese older adults, the prevalence of frailty, which was characterized using three or more limitations(shrinking, exhaustion, low activity, slowness, and weakness), was 5.2% and 12.0% in men and women, respectively. The prevalence of sarcopenia based on a diagnosis of low appendicular muscle mass, low grip strength, and low gait speed was 9.6% in men and 7.7% in women. Further, the prevalence of frailty with comorbidity of sarcopenia was 21.6% and 52.2% in men and women, respectively, and the prevalence of sarcopenia with comorbidity of frailty was 28.6% and 34.4% in men and women, respectively. The estimated number of prevalent cases of frailty, pre-frailty, and sarcopenia in Japanese older adults was approximately 3,090,000, 17,950,000, and 2,710,000, respectively.