The Japanese dietary pattern rich in legumes, fish, vegetables, fruit and mushrooms is protective towards the risk of developing dementia.
Tomata Y, Sugiyama K, Kaiho Y, Honkura K, Watanabe T, Zhang S, Sugawara Y, Tsuji I. Dietary Patterns and Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study. J Gerontol A Biol Sci Med Sci. 2016 Oct;71(10):1322-8. doi: 10.1093/gerona/glw117. https://www.ncbi.nlm.nih.gov/pubmed/27356978
Zhang S, Tomata Y, Sugiyama K, Sugawara Y, Tsuji I. Mushroom Consumption and Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study. J Am Geriatr Soc. 2017 Jul;65(7):1462-1469. doi: 10.1111/jgs.14812. Epub 2017 Mar 13. https://www.ncbi.nlm.nih.gov/pubmed/28295137