Objective: To review large-scale Japanese cohort studies examining the relationship between dietary patterns, specific food components, and dementia risk.

Methods: Systematic review of major Japanese cohort studies including Hisayama, NILS-LSA, JPHC, Ohsaki, and SONIC.

Results: Consistent evidence across cohorts demonstrated that adherence to a traditional Japanese dietary pattern, characterized by high consumption of fish, soy products, vegetables, green tea, and adequate dairy intake, was associated with reduced dementia risk. The Hisayama Study showed a 34% reduction in all-cause dementia risk for those with high adherence to a Japanese dietary pattern. NILS-LSA reported a 42% lower risk of dementia for participants in the highest tertile of the weighted Japanese Diet Index. The Ohsaki Cohort found a 21% reduction in dementia risk for those with the highest adherence to the Japanese Diet Index. Dietary diversity was consistently linked to lower dementia risk across studies.

Discussion: The protective effects of the Japanese diet are likely due to the synergistic action of various nutrients and food components, including n-3 polyunsaturated fatty acids, isoflavones, and antioxidants. These components may reduce neuroinflammation and oxidative stress. While these observational studies provide valuable insights, caution is warranted in drawing causal inferences. Future research should focus on randomized dietary intervention trials and explore AI-driven personalized nutrition strategies for targeted dementia prevention.

Conclusion: Traditional Japanese dietary patterns may reduce dementia risk, informing dietary strategies for cognitive health in aging populations.

Objective: This study evaluates the relationship between information access and media literacy attitudes. We also assessed the impact of “Medical Literature Reading” on media literacy among Japanese university students. Methods: A cross-sectional study was conducted from April 2–16 and from August 2–16, 2024. A self-reporting questionnaire, including the school year, was used to determine if participants had taken the “Medical Literature Reading” course and to identify the sources often used for reporting assignments and media literacy. Results: This study included 195 subjects. The differences in media literacy scores between school years were analyzed. The total scores of fourth-year students were significantly higher than those of first-year on the media literacy scale (p = 0.014). The differences in media literacy scores among students enrolled in “Medical Literature Reading” were analyzed. The scores on the media literacy scale (p = 0.006) were significantly higher in participants than in non-participants. The relationships among the three groups by sources used for report assignments, school years (χ²(6) = 42.101, p < 0.0001), and history of taking “Medical Literature Reading” (χ²(2) = 7.048, p = 0.030) were also analyzed. Conclusions: Media literacy improved with schooling. Certain report assignments and subjects related to information literacy were found to have affected media literacy. Combining continuing experience and knowledge can lead to improvements in media literacy.

Intuitive Eating (IE) is an approach that encourages individuals to eat according to their body’s hunger and fullness cues, aiming to establish a healthy relationship with food without restrictions. This study investigated the association between IE and psychological factors (optimism, life satisfaction, proactive coping, and self-esteem) among Japanese university students. The results showed that, among female students, IE was positively correlated with life satisfaction and optimism. Additionally, students with no history of dieting tended to have higher IES-2 scores, suggesting that prior dieting experience may be associated with lower adherence to intuitive eating principles. These findings suggest that nutrition guidance incorporating IE may be effective as psychological support in future interventions.

This study was conducted to clarify the relationship between sleep disorders and frequency, or timing of dairy intake with 192 university students in Japan. Pearson’s chi-squared test was carried out to find the relationship between two groups of sleep disorders and the timing of dairy product intake (p = 0.034, df = 4, χ² = 10.38). The sleep disorder occurred significantly less if participants took a dairy product in the morning (p = 0.004) and significantly more when participants took a dairy product in the afternoon (p = 0.028). The findings showed that consuming dairy products in the morning is effective in treating sleep disorders.

During the COVID-19 pandemic in Japan, special nursing home staff often requested that home-visit dental treatment be discontinued. Even after the pandemic was recategorized as a class five infectious disease, infection control measures persisted in these homes. This case report presents treatment at a special nursing home where visiting dental care is restricted as an infection control measure. A 90-year-old woman in one of the homes refused to wear dentures, even after becoming infected with COVID-19, and sought care after a near-choking incident involving a sweet red bean bun. Although only five roots remained in the oral cavity, the food texture was unsuitable for gum mastication. Because the patient’s refusal to wear dentures was thought to be due to impaired cognitive function, forgoing dentures and dietary modification to reduce the risk of choking were recommended. Due to wet phlegm accumulation in the oral cavity, the patient was also instructed on oral care methods to prevent aspiration pneumonia, and oral hygiene management was implemented. As a result, the patient no longer had wet phlegm but refused to wear the dentures. We instructed the facility staff to continue the changed dysphagia diet. This report presents the efficacy of medical-care coordination for home-visit dental treatment, within the limitations of emerging infectious diseases.