Greater consumption of caffeinated coffee and tea was associated with lower risk of dementia and modestly better cognitive function, with the most pronounced association at moderate intake levels https://jamanetwork.com/journals/jama/article-abstract/2844764 Koffein schützt offenbar vor Demenz https://www.mdr.de/wissen/medizin-gesundheit/koffein-koennte-vor-demenz-schuetzen-100.html Moderate consumption of coffee and tea can reduce the risk of developing a disease by ~ 20 %. However, this does not apply to decaffeinated coffee