A study published in Neurology on July 18, 2026, has linked higher consumption of common sugar substitutes to accelerated cognitive decline and faster memory loss in adults.
The strongest associations were observed among individuals under age 60 and those with diabetes.
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Researchers monitored 12,772 Brazilian adults with an average age of 52 over approximately eight years.
They evaluated the effects of seven low- and no-calorie sweeteners commonly found in diet beverages, yogurt, and low-calorie desserts.
Participants who consumed the highest daily amounts of these sweeteners experienced a 62% faster rate of decline in memory and thinking skills compared to those with the lowest intake.
This effect is equivalent to roughly 1.6 additional years of brain aging.
Specific Sweeteners and Their Impact
The study assessed seven compounds: aspartame, saccharin, acesulfame K, erythritol, xylitol, sorbitol, and tagatose.
Except for tagatose, every individual sweetener was separately tied to accelerated cognitive decline, particularly affecting memory retention, verbal fluency, and processing speed.
"Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar, however our findings suggest certain sweeteners may have negative effects on brain health over time," said study author Dr. Claudia Kimie Suemoto of the University of São Paulo.
Participants in the highest intake group consumed an average of 191 milligrams per day of sweeteners—equivalent to the aspartame content in one can of diet soda.
Those in the lowest group averaged 20 milligrams daily.
Middle-tier consumers showed a 35% faster rate of cognitive decline, corresponding to about 1.3 years of accelerated aging.
