Notably, of the seven sweeteners studied, only one — tagatose — was not linked to cognitive decline. There was also stronger connection between sweetener intake and faster cognitive decline among people with diabetes compared with those without the condition. “While we found links to cognitive decline for middle-aged people both with and without diabetes, people with diabetes are more likely to use artificial sweeteners as sugar substitutes,” Suemoto said. Most importantly, the study was observational, identifying a relationship between higher sweetener consumption and faster cognitive decline, but it could not establish that the sweeteners caused those changes. The results do not show that sweeteners directly cause cognitive decline: they reveal an association, meaning other factors could help explain the pattern.