Scientists Link These Six Common Sugar Substitutes to Faster Decline in Brain Function

Artificial sweeteners commonly used in diet drinks and low-calorie foods may be linked to faster memory and thinking decline, according to a new study. Researchers found that people consuming the highest amounts of certain sugar substitutes experienced a 62% faster decline in cognitive performance compared with those consuming the least.

Published in the journal Neurology, the study conducted by researchers at the University of São Paulo, Brazil, examined the relationship between low- and no-calorie sweetener consumption and long-term brain health.

Researchers analysed data from 12,772 adults with an average age of 52 years, following participants for approximately eight years.

Dietary questionnaires were used to estimate consumption of seven commonly used sweeteners, including aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol and tagatose.

Participants were divided into three groups based on daily sweetener consumption. The lowest intake group consumed approximately 20 milligrams daily, while the highest consumed around 191 milligrams.

The findings revealed that participants with the highest sweetener intake experienced a 62% faster decline in overall memory and thinking abilities compared with those consuming the least.

Researchers estimated that this difference was equivalent to approximately 1.6 additional years of cognitive aging.

Even participants with moderate sweetener consumption experienced a 35% faster cognitive decline, equivalent to approximately 1.3 additional years of cognitive aging.

Interestingly, the association was more pronounced among adults younger than 60 years and people with diabetes.

Six sweeteners, including aspartame, saccharin, acesulfame-K, erythritol, sorbitol and xylitol, were associated with faster cognitive decline. Tagatose showed no significant association.

However, researchers emphasised that the observational study cannot establish whether artificial sweeteners directly cause cognitive impairment.

The findings highlight the need for further research into the long-term neurological effects of sugar substitutes, particularly among individuals with diabetes and middle-aged adults.

REFERENCE: Natalia Gomes Gonçalves, et al.; Association Between Consumption of Low- and No-Calorie Artificial Sweeteners and Cognitive Decline. Neurology, 2025; 105 (7) DOI: 10.1212/WNL.0000000000214023