Guardians' food literacy and breakfast skipping among Japanese school children.

Children and adolescents who regularly skip breakfast are at a greater risk of obesity than those who regularly eat breakfast. Guardian's food literacy, defined in this study as a collection of a guardian's knowledge, skill, and attitude towards healthy food practices, may directly influence their child's dietary habits. Thus, this study utilized a food literacy scale to assess the relationship between guardians' food literacy and breakfast skipping among school-attending Japanese children and adolescents and the most commonly reported reasons for skipping breakfast. This was a cross-sectional study using survey data collected from a nationally representative sample of households in Japan (n = 1520). Our results show that 13.0% of children self-reported skipping breakfast at least once a week. Children in households where guardians reported higher knowledge and attitude scores had significantly lower odds of skipping breakfast (odds ratios = 0.90 [95% confidence interval: 0.83-0.98] and 0.81 [0.74-0.90], respectively). These findings suggest that a guardian's attitude and knowledge towards healthy food practices influence the frequency at which their child eats breakfast. Moreover, lower parental attitude scores were associated with children skipping due to not having enough time for breakfast in the morning. Improving guardians' food literacy may provide an avenue by which to decrease the rate of breakfast skipping among children and adolescents, thereby decreasing the risk of obesity and other adverse health outcomes.

Association between screen time, including that for smartphones, and overweight/obesity among children in Japan: NICE EVIDENCE Study 4.

The association between screen time (ST), including that for smartphones, and overweight/obesity in children was examined separately for boys and girls, considering the influence of lifestyle factors. A cross-sectional study was conducted in 2,242 Japanese children (1,278 girls) aged 10-14 years. Overweight/obesity was defined by the International Obesity Task Force. Logistic regression analysis showed that only for girls, total ST (≥4 h), smartphone ST (≥3 h), and non-smartphone ST (≥2 h) were all independently and significantly associated with overweight/obesity compared to <2 h total ST, non-use of smartphones, and <1 h non-smartphone ST. Thus, smartphone ST ≥3 h and non-smartphone ST ≥2 h were additively associated with overweight/obesity in girls only. Girls having smartphone ST ≥3 h and non-smartphone ST ≥2 h were 6.79 times (95% CI: 3.11-14.81) more likely to have overweight/obesity than girls with less usage of both. In girls, when total ST was ≥4 < 5 h or smartphone ST was ≥2 h, the significant association with overweight/obesity disappeared when physical activity was ≥60 min/day and sleep time was ≥8.5 h. In addition, none of these associations was significant in boys. In Japanese girls, smartphone ST, non-smartphone ST, and total ST were all significantly associated with overweight/obesity. To avoid overweight/obesity, it is suggested to keep smartphone ST, non-smartphone ST, and total ST to <3 h, <2 h, and <4 h, respectively, and to engage in sufficient physical activity and sleep time.

Lifestyle Intervention With Smartphone App and isCGM for People at High Risk of Type 2 Diabetes: Randomized Trial.

AIMS: Although conventional interventions for people at high risk of developing type 2 diabetes are usually conducted face-to-face, such interventions are burdensome for health care providers. We developed a lifestyle intervention program combining lifestyle coaching via a smartphone application augmented by intermittently scanned continuous glucose monitoring without burdening health care providers. Its effectiveness for glycemic control and body weight reduction in people at risk of type 2 diabetes was investigated. MATERIALS AND METHODS: For this 12-week randomized unblinded trial with offline recruitment, participants with a hemoglobin A1c level of 5.6% to 6.4% or a fasting blood glucose of 110 to 125 mg/dL and body mass index (BMI) >23 kg/m2 but <40 kg/m2 were randomly assigned to the intervention group (App) and control group (C). The primary endpoint was the difference in time in range of blood glucose between 70 and 140 mg/dL (3.9-7.8 mmol/L) before and after the study period between the 2 groups. RESULTS: Among 168 patients (mean age, 48.1 years; mean BMI, 26.6 kg/m2; and male, 80.4%), 82 and 86 were assigned to the App group and C group, respectively. After 12 weeks, time in range of blood glucose at 70 to 140 mg/dL significantly improved in the App group compared with the C group (-2.6 minutes/day vs +31.5 minutes/day, P = .03). Changes in time above range did not differ, whereas time below range (blood glucose <70 mg/dL; +23.5 minutes/day vs -8.9 minutes/day, P = .02) improved in the App group. BMI (-0.26 vs -0.59, P = .017) was reduced in the App group compared with the C group. CONCLUSION: Intervention with a smartphone app and intermittently scanned continuous glucose monitoring increased glycemic control accompanied by decreased carbohydrate intake and weight loss. Further trials are needed to confirm whether these interventions can reduce incident type 2 diabetes.

Associations among metabolic health, weight status, and various physical fitness components in Japanese adolescents: a cross-sectional study (NICE EVIDENCE study- Agano 3).

Aim was to examine associations among metabolic health, weight status, and various physical fitness (PF) components in 1744 Japanese adolescents aged 13-14. Anthropometric measurements and PF tests (20 m shuttle run test [20mSRT], handgrip strength/body mass [HG], standing long jump [SLJ], and sit ups [SU]) were administered. The bottom sex-specific quintile of PF indicated "low fit". Participants were classified as non-overweight (non-OW) or overweight/obese (OW) according to the International Obesity Task Force. Clustered metabolic risk was defined as the sum of Z scores for mean arterial pressure, non-high-density lipoprotein cholesterol, and HbA1c, divided by three, and ≥ 1 SD. Combination of weight status and scores for HG or SU were additively associated with clustered metabolic risk. Compared with the non-OW-moderate-high fit group, the OW-low HG group was 3.05 (95%CI: 1.88-4.97) times more likely to have clustered metabolic risk although risk was not significantly elevated in the OW-moderate-high HG group (1.52 [95%CI: 0.88-2.62]). A similar association was observed between OW and low SU scores but not between OW and low 20mSRT or SLJ scores. Adolescents with OW and moderate-high HG or SU scores had a lower prevalence of an unfavourable metabolic state than those with OW and low HG or SU results.

Machine learning approach to predict body weight in adults.

Background: Obesity is an established risk factor for non-communicable diseases such as type 2 diabetes mellitus, hypertension and cardiovascular disease. Thus, weight control is a key factor in the prevention of non-communicable diseases. A simple and quick method to predict weight change over a few years could be helpful for weight management in clinical settings. Methods: We examined the ability of a machine learning model that we constructed to predict changes in future body weight over 3 years using big data. Input in the machine learning model were three-year data on 50,000 Japanese persons (32,977 men) aged 19-91 years who underwent annual health examinations. The predictive formulas that used heterogeneous mixture learning technology (HMLT) to predict body weight in the subsequent 3 years were validated for 5,000 persons. The root mean square error (RMSE) was used to evaluate accuracy compared with multiple regression. Results: The machine learning model utilizing HMLT automatically generated five predictive formulas. The influence of lifestyle on body weight was found to be large in people with a high body mass index (BMI) at baseline (BMI ≥29.93 kg/m2) and in young people (<24 years) with a low BMI (BMI <23.44 kg/m2). The RMSE was 1.914 in the validation set which reflects ability comparable to that of the multiple regression model of 1.890 (p = 0.323). Conclusion: The HMLT-based machine learning model could successfully predict weight change over 3 years. Our model could automatically identify groups whose lifestyle profoundly impacted weight loss and factors the influenced body weight change in individuals. Although this model must be validated in other populations, including other ethnic groups, before being widely implemented in global clinical settings, results suggested that this machine learning model could contribute to individualized weight management.

Japanese school children's intake of selected food groups and meal quality due to differences in guardian's literacy of meal preparation for children during the COVID-19 pandemic.

In 2020, a state of emergency (SOE) was enforced by the Japanese government, which included temporary school closures with the aim of overcoming COVID-19 spread, which prevented access to school lunches. We evaluated the relationship between meal quality and guardians' literacy of meal preparation for a nationally representative sample of 1107 Japanese schoolchildren (aged 10-14 years) before, during, and after the SOE on the basis of 7 questions scored using a 5-point Likert scale. The guardians' literacy of meal preparation for children was divided into quartiles, with Q1 and Q4 including participants with the lowest and highest scores on food literacy, respectively. School lunch menu was handed out monthly to each household by their classroom teacher. The consumption of (i) meat, fish, or eggs and (ii) vegetables at least twice a day indicated "well-balanced dietary intake", which was less frequent in all four quartiles, especially for Q1 and Q2, during compared to before the SOE. The relative risk increases (95% CI) were Q1: -40.6% (-41.4% to -39.8%; p < 0.001), Q2: -34.0% (-34.7% to -33.3%; p < 0.001), Q3: -13.1% (-13.8% to -12.4%; p < 0.001), and Q4: -15.3% (-16.0% to -14.7%; p < 0.001), adjusted for sex, age, BMI, equivalent income adjusted for the number of household members, and educational level of parents. The interaction p was <0.001 for Q1-3 vs. Q4. Guardians with low total scores were significantly more likely to have less time, mental capacity, and financial ability to prepare meals after the SOE. Therefore, schoolchildren's meal quality deteriorated during the SOE, particularly among those with guardians with low food literacy even after adjustment for household income level and guardians' educational level.

Association between Obesity and Intake of Different Food Groups among Japanese with Type 2 Diabetes Mellitus-Japan Diabetes Clinical Data Management Study (JDDM68).

BACKGROUND: We investigated the association between various food groups and obesity in Japanese patients with type 2 diabetes. METHODS: 2070 patients with type 2 diabetes who attended 26 diabetes clinics throughout Japan were analyzed and were divided into obese and non-obese groups. Intakes of food groups determined by a food frequency questionnaire were compared. Odds ratios for obesity for quartiles of individual food groups were calculated using a logistic regression model. RESULTS: Non-obese patients consumed a larger variety of food groups than obese patients, with the diets of non-obese individuals closer to the traditional Japanese diet characterized by fish, seaweed, and soybeans/soy products. Among 21 food groups, low vegetable intake and high sweets intake were the most strongly associated with obesity in both men and women. Low intake of both fruits and vegetables and the combination of high intake of sweets and low intake of fruits were associated with obesity. CONCLUSIONS: Food groups and their combinations that were strongly associated with obesity in Japanese patients with type 2 diabetes were identified. Our findings also suggested an inverse association between the traditional Japanese diet and obesity.

The association between long-chain polyunsaturated fatty acid intake and changes in brain volumes among older community-dwelling Japanese people.

The relationship between age-related brain atrophy and long-chain polyunsaturated fatty acid (LCPUFA) intake is not fully understood. This study investigated the association of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) intake and brain atrophy in non-demented older Japanese people (n = 810, aged 60-89 years) using data sets of a 2-year longitudinal study. Brain volumes were measured using 3D-MRI in the baseline and follow-up periods. The associations of multivariate-adjusted changes in brain volumes with baseline LCPUFA intake were assessed using a general linear model. Higher ARA intake was associated with a smaller decrease in frontal cortex volumes, which was accompanied by a lower risk of cognitive decline among the participants. In the subgroup analysis for low DHA and EPA intake, accounting for one-third of Japanese intake, DHA and EPA intake was positively correlated with preservation of the temporal cortex volume. These findings suggest that appropriate intake of LCPUFA may decelerate age-related brain atrophy and lead to the maintenance of brain health in older people.

Dietary intake and physical activity in Japanese patients with type 2 diabetes: the Japan Diabetes Complication and its Prevention prospective study (JDCP study 8).

Medical nutrition therapy and exercise therapy are the cornerstones of treatment for patients with type 2 diabetes; however, there has not been a nationwide study on the actual dietary intake and physical activity status of patients since the 2000s. We aimed to clarify this in Japanese patients with type 2 diabetes using data from the Japan Diabetes Complication and its Prevention prospective (JDCP), a nationwide study launched in 2007. A total of 1992 patients with type 2 diabetes, aged 40-75 years, completed either the Brief-type, self-administered Diet History Questionnaire (1643 patients) or International Physical Activity Questionnaire (1834 patients), and their data were analyzed in this study. Mean daily energy intake for all participants was 1686.8 kcal/day, and the mean proportions of carbohydrate, protein, and fat comprising total energy intake were 60.2, 16.2, and 23.6%, respectively. The patients in this study had similar energy and nutrient intake status to patients in the 1996 Japan Diabetes Complications Study; however, Japanese patients still had higher carbohydrate and lower fat consumption than patients with diabetes in Western countries. The physical activity questionnaire reported that 31.0% of patients did not have exercise habits; this was particularly noticeable in female patients and patients under the age of 65. BMI increased from 22.7 to 24.1 kg/m2 in men and 23.2 to 24.8 kg/m2 in women from 1996 to 2007, respectively. Further research is required to investigate how dietary intake and physical activity associates with the risk of developing complications in type 2 diabetes patients.

Higher Iron Intake Is Independently Associated with Obesity in Younger Japanese Type-2 Diabetes Mellitus Patients.

We aimed to analyze the association between dietary iron intake and obesity assessed by BMI after adjustment for nutrient intake (macronutrients and fiber) and food groups. The study design was cross-sectional. Patients with type-2 diabetes (n = 1567; 63.1% males; mean age 62.3 ± 11.6 years) were included in the study. To assess diet, consumption of typical food groups was determined by a food frequency questionnaire. Obesity was defined as BMI ≥ 25 kg/m2. We performed a binary regression analysis between quartiles of iron intake and obesity by quartiles of age group. A direct linear association was found for the highest quartile of iron intake and obesity in the younger age group of 30 to 54 years (OR = 3.641, 95% CI = 1.020-12.990; p trend = 0.011). Multivariate analysis using food groups as opposed to nutrients revealed a positive trend for obesity in the younger age group after adjusting for lifestyle factors, energy intake and bean and vegetable intake (p trend = 0.023). In all participants, an inverse association was observed before adjustment by vegetable intake (OR = 0.453, 95% CI = 0.300-0.684; p trend = 0.001). Higher iron intake was associated with obesity independent of macronutrient and fiber intake but only in the youngest quartile of age group examined.

Leisure-time physical activity and incidence of objectively assessed hearing loss: The Niigata Wellness Study.

Previous cohort study reported that high physical activity was associated with a low risk of self-reported hearing loss in women. However, no studies have examined the association between physical activity and the development of hearing loss as measured using an objective assessment of hearing loss in men and women. Here, we used cohort data to examine the association between leisure-time physical activity and incidence of objectively assessed hearing loss in men and women. Participants included 27 537 Japanese adults aged 20-80 years without hearing loss, who completed a self-administered physical activity questionnaire between April 2001 and March 2002. The participants were followed up for the development of hearing loss as measured by audiometry between April 2002 and March 2008. During follow-up, 3691 participants developed hearing loss. Compared with the none physical activity group, multivariable adjusted hazard ratios (HRs) for developing hearing loss were 0.93 (95% confidence interval (CI), 0.86-1.01) and 0.87 (0.81-0.95) for the medium (<525 MET-min/week) and high (≥525 MET-min/week) physical activity groups, respectively (p for trend = 0.001). The magnitude of risk reduction was slightly greater in vigorous-intensity activity than in moderate-intensity activity (p for interaction = 0.01). Analysis by sound frequency showed that the amount of physical activity was inversely associated with high frequency hearing loss development (p for trend <0.001), but not with low frequency hearing loss development (p for trend = 0.19). Higher level of leisure-time physical activity was associated with lower incidence of hearing loss, particularly for vigorous-intensity activities and high sound frequencies.

Predictive ability of current machine learning algorithms for type 2 diabetes mellitus: A meta-analysis.

AIMS/INTRODUCTION: Recently, an increasing number of cohort studies have suggested using machine learning (ML) to predict type 2 diabetes mellitus. However, its predictive ability remains inconclusive. This meta-analysis evaluated the current ability of ML algorithms for predicting incident type 2 diabetes mellitus. MATERIALS AND METHODS: We systematically searched longitudinal studies published from 1 January 1950 to 17 May 2020 using MEDLINE and EMBASE. Included studies had to compare ML's classification with the actual incidence of type 2 diabetes mellitus, and present data on the number of true positives, false positives, true negatives and false negatives. The dataset for these four values was pooled with a hierarchical summary receiver operating characteristic and a bivariate random effects model. RESULTS: There were 12 eligible studies. The pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio were 0.81 (95% confidence interval [CI] 0.67-0.90), 0.82 [95% CI 0.74-0.88], 4.55 [95% CI 3.07-6.75] and 0.23 [95% CI 0.13-0.42], respectively. The area under the summarized receiver operating characteristic curve was 0.88 (95% CI 0.85-0.91). CONCLUSIONS: Current ML algorithms have sufficient ability to help clinicians determine whether individuals will develop type 2 diabetes mellitus in the future. However, persons should be cautious before changing their attitude toward future diabetes risk after learning the result of the diabetes prediction test using ML algorithms.

Secular Trends in Dietary Intake over a 20-Year Period in People with Type 2 Diabetes in Japan: A Comparative Study of Two Nationwide Registries; Japan Diabetes Complications Study (JDCS) and Japan Diabetes Clinical Data Management Study (JDDM).

BACKGROUND: In order to provide effective dietary guidance, it is necessary to consider dietary intake, which can change over time. This study analyzed changes in the diet of Japanese patients with type 2 diabetes over a 20-year period. METHODS: We compared the results of two dietary surveys that used the food frequency questionnaire format. The first was conducted in 1996 by the Japan Diabetes Complications Study (JDCS) (n = 1509; males 53.3%), and the second in 2014-2018 by the Japan Diabetes Clinical Data Management Study (JDDM) (n = 1145; males 65.6%). Both are nationwide representative registries of outpatients with type 2 diabetes in Japan. RESULTS: Over a 20-year period, both men and women with type 2 diabetes had a significant increase in body mass index (BMI). Nonetheless, there was only a small change in energy intake. Conversely, there was a significant increase in fat intake and thus in the fat-to-energy ratio. With regard to food groups, there was a significant increase in meat intake and a decrease in the intake of fish, soybeans/soy products, vegetables, and fruits, with a particularly significant decrease in vegetables. CONCLUSIONS: Even in Japan, an industrialized country with a stable socioeconomic environment, there were many significant changes in the dietary intake of patients with type 2 diabetes over the 20-year period.

Carrot Consumption Frequency Associated with Reduced BMI and Obesity through the SNP Intermediary rs4445711.

It is unclear whether genetic interactions are involved in the association between vegetable intake and reduced body mass index (BMI) or obesity. We conducted a comprehensive search for single nucleotide polymorphisms (SNPs) which are associated with the interaction between vegetable intake frequency and BMI or obesity. We performed a genome-wide association analysis to evaluate the genetic interactions between self-reported intake of vegetables such as carrot, broccoli, spinach, other green vegetables (green pepper and green beans), pumpkin, and cabbage with BMI and obesity, which is defined as a BMI ≥ 25.0 kg/m2 in the Japanese population (n = 12,225). The mean BMI and prevalence of obesity was 23.9 ± 3.4 kg/m2 and 32.3% in men and 22.1 ± 3.8 kg/m2 and 17.3% in in women, respectively. A significant interaction was observed between rs4445711 and frequency of carrot intake on BMI (p = 4.5 × 10-8). This interaction was slightly attenuated after adjustment for age, sex, alcohol intake, smoking, physical activity and the frequency of total vegetable intake (p = 2.1 × 10-7). A significant interaction was also observed between rs4445711 and frequency of carrot intake on obesity (p = 2.5 × 10-8). No significant interactions that were the same as the interaction between frequency of carrot intake and rs4445711 were observed between the intake frequency of broccoli, spinach, other green vegetables, pumpkin or cabbage and BMI or obesity. The frequency of carrot consumption is implicated in reducing BMI by the intermediary of rs4445711. This novel genetic association may provide new clues to clarify the association between vegetable intake and BMI or obesity.

Comparing Associations of Dietary Energy Density and Energy Intake, Macronutrients with Obesity in Patients with Type 2 Diabetes (JDDM 63).

To investigate the association between dietary energy density (DED) and obesity in people with type 2 diabetes mellitus. Moreover, we compared the strength of the associations of DED with intake of energy and macronutrients in terms of obesity as well as nutritional factors that have long been used for medical nutritional therapy. Cross-sectionally investigated were 1615 outpatients with type 2 diabetes who attended 26 clinics nationwide with diabetes specialists. Odds ratios (ORs) were calculated for the association between obesity and DED, energy, and macronutrients by quintile categories and a 1 SD increment with adjustment for potential confounders. ß coefficients were calculated for the association between body mass index (BMI) and each nutritional factor by 1 SD increments in nutritional values. Multi-adjusted OR for obesity between extreme quintiles of DED was 2.99 (95% confidence interval (95% CI): 2.01-3.12). Conversely, the ORs did not differ significantly according to the quintiles of other nutrient factors. Multi-adjusted ß coefficient of BMI per 1 SD according to DED was far higher than those of other nutrient factors (ß coefficient 0.65, 95% CI: 0.41-0.88). These findings indicated that DED in persons with type 2 diabetes was positively associated with BMI and the prevalence of obesity. DED was also much more potently associated with obesity and BMI than nutritional indicators such as intake of energy or macronutrients.

Changes in Selected Food Groups Consumption and Quality of Meals in Japanese School Children during the COVID-19 Pandemic.

In 2020, a state of emergency was declared to control the devastating impact of coronavirus, leading to temporary school closures in Japan, meaning that school lunches were not provided to the majority of schoolchildren. Using questionnaires completed by participants' guardians, we examined the relationship between household income and the quality of meals in Japanese schoolchildren before, during, and after the state of emergency. Participants (1111 children, 10-14 years old) were chosen to form a nationally representative sample of the Japanese population. "Well-balanced dietary intake" was defined as the intake of (i) meat, fish, or eggs and (ii) vegetables. The desired prevalence was defined as equal to or more than twice a day. Household income was divided into quartiles. "Well-balanced dietary intake" was lower in all households during the state of emergency compared with before. The proportion of those with a "well-balanced dietary intake" at least twice a day was notably low in both Q3 and Q4 during the state of emergency compared with before the declared state of emergency; relative risk increase (95% CI) were Q1: -19.0% (-19.6% to -18.4%), p < 0.001, Q2: -21.3% (-22.1% to -20.6%) p < 0.001, Q3: -25.4% (-26.1% to -24.7%), p < 0.001, and Q4: -34.8% (-35.6% to -34.0%), p < 0.001. The interaction p (vs. Q1) of Q2, Q3, and Q4 were all <0.001. Guardians from low-income households had significantly higher rates of having less: time, psychological room, and financial position to prepare meals during the state of emergency. Our results suggest that schoolchildren's quality of meals worsened during the state of emergency, especially in low-income households, because school lunches were not provided.

Developing a health economic model for Asians with type 2 diabetes based on the Japan Diabetes Complications Study and the Japanese Elderly Diabetes Intervention Trial.

INTRODUCTION: Cost-effectiveness analyses are becoming increasingly important in Japan following the introduction of a health technology assessment scheme. The study objective was to develop an economic model to evaluate the cost-effectiveness of two interventions for type 2 diabetes in a Japanese population. RESEARCH DESIGN AND METHODS: The Japan Diabetes Complications Study/Japanese Elderly Diabetes Intervention Trial risk engine (JJRE) Cost-Effectiveness Model (JJCEM) was developed, incorporating validated risk equations in Japanese patients with type 2 diabetes from the JJRE. Weibull regression models were developed for progression of the model outcomes, and a targeted literature review was performed to inform default values for utilities and costs. To illustrate outcomes, two simulated analyses were performed in younger (aged 40 years) and older (aged 80 years) Japanese populations, comparing a hypothetical treatment with placebo. RESULTS: The model considers a population based on user-defined values for 11 baseline characteristic parameters and simulates rates of diabetic complications over a defined time horizon. Costs, quality-adjusted life years, and an incremental cost-effectiveness ratio are estimated. The model provides disaggregated results for two competing interventions, allowing visualization of the key drivers of cost and utility. A scatterplot of simulations and cost-effectiveness acceptability curve are generated for each analysis. CONCLUSIONS: This is the first cost-effectiveness model for East Asian patients with type 2 diabetes, developed using Japan-specific risk equations. This population constitutes the largest share of the global population with diabetes, making this model highly relevant. The model can be used to evaluate the cost-effectiveness of anti-diabetic interventions in patients with type 2 diabetes in Japan and other East Asian populations.

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.