2025 Volume 3 Issue 1 Pages 1-10
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.
