Study Links 6 Popular Sugar Substitutes to Faster Memory Decline
Six sweeteners used in everyday diet products were associated with faster cognitive decline in a large Brazilian study . For calorie-conscious shoppers, the findings offer a reason to check ingredients—and understand the study's limits.
The six were aspartame, saccharin, acesulfame-K, erythritol, sorbitol and xylitol . Researchers found no association for tagatose, the seventh sweetener examined. This is research first published in 2025, not a new November 2026 trial.
Related: New Study Links Ultra-Processed Foods to $359,836 in Lifetime Costs, but There's a Catch
Related: Scientists Compared Diet Soda and Water for 2 Years and Found an Unexpected Result
The Finding Was Strongest Before 60
Researchers followed 12,772 adults, averaging 52 years old, for roughly eight years. Participants reported their diets and completed tests of memory, language and thinking.
The American Academy of Neurology's updated release reports 63% faster cognitive decline among the highest consumers compared with the lowest, after statistical adjustments. That describes a difference in decline rates—not a 63% increase in dementia risk.
The association appeared among participants younger than 60; researchers found no link in older participants. It was stronger among people with diabetes.
Study author Claudia Kimie Suemoto, MD, PhD, of the University of São Paulo, said "certain sweeteners may have negative effects on brain health over time." She added: "More research is needed to confirm our findings."
Related: Drink Diet Soda Every Day? A Major Study Found a Surprising Brain-Health Link
An Important Correction Accompanies the Results
The journal corrected and replaced the paper in July 2026 after the authors audited and reran their analysis.
"The changes did not affect the main conclusions from the paper," the correction states. "The authors regret the errors."
Still, this was observational research relying on self-reported diet. It cannot establish that sweeteners caused the changes or identify a personal danger threshold.
The researchers also clarify their comparison : "Finally, our goal was to examine LNCS consumption in relation to cognitive decline, not to compare sweeteners with sugar."
Related: Scientists Found a Hidden Stress Trigger in Your Living Room That You Can Fix
Related: Are 'Natural' Sugars Like Honey and Agave Really Healthier? Expert Weighs In
Start With the Ingredient List
The ingredients can appear in flavored waters, sodas, energy drinks, yogurts and low-calorie desserts. Finding one on a label does not establish that the product will harm your memory.
"Consumers can identify whether a product has a sweetener by looking for the sweetener's name in the ingredient list on the product label," the FDA explains .
The CDC adds : "Zero-calorie sweeteners have little to no effect on blood sugar levels and can help you reduce calorie intake."
Takeaway: Check your regular purchases, consider unsweetened options, and discuss diabetes-related dietary changes with your clinician. This study raises questions; it doesn't prescribe a switch back to sugar.
Related: Scientists Discover Why the Mediterranean Diet May Protect Your Brain and Heart
Related: Scientists Link Red Meat to 63% Higher Diabetes Risk, but Discover a Surprising Exception
This story was originally published by Men's Journal on Nov 3, 2026, where it first appeared in the Health section. Add Men's Journal as a Preferred Source by clicking here.
