A large prospective study published in the journal Neurology has found that adults with the highest intake of low- and no-calorie sweeteners experience cognitive decline up to 62% faster than those who consume the least — a difference equivalent to 1.6 years of excess brain aging. For anyone tracking their long-term health through evidence-based nutrition guidance, the findings add a meaningful new dimension to the ongoing debate over sugar substitutes.
What the Research Found
The study tracked 12,772 civil servants free of dementia at baseline over a median of eight years, measuring intake of seven common sweeteners: aspartame, saccharin, acesulfame potassium, erythritol, sorbitol, xylitol, and tagatose. Participants in the top intake group showed a 62% faster rate of global cognitive decline compared with the lowest group. Verbal fluency declined 173% faster, while episodic memory dropped 32% more steeply. The effects were most pronounced among participants under 60 and those living with diabetes. As reported by Neurology (American Academy of Neurology), the study is observational and does not establish causation, but researchers note that “long-term reliance on low-calorie artificial sweeteners may present unrecognized risks to long-term neurological health.”
What It Means for Everyday Dietary Choices
The findings arrive at a moment when ultra-processed foods — many of which lean heavily on sweetener blends — are already under scrutiny for cardiovascular and metabolic risks. Dietitians have long cautioned that swapping sugar for sweeteners is not a neutral trade, and this research adds neurological trajectory to the list of concerns worth discussing with clients. The authors emphasize that people with diabetes, a group that often uses sweeteners most intensively, showed the sharpest cognitive impacts — underscoring the need for individualized dietary counseling rather than blanket substitution advice.