Chicago – A common addition to morning coffee may be associated with faster brain aging, according to a new long-term study that tracked more than 12,000 adults for eight years.
According to researchers publishing in the journal Neurology, people with the highest consumption of low- and no-calorie sweeteners experienced a faster decline in measures of global cognition and verbal fluency, particularly among adults younger than 60. The study followed 12,772 participants with an average age of nearly 52 and evaluated dietary habits alongside repeated cognitive testing over an eight-year period.
The researchers examined seven commonly used sweeteners, including aspartame, saccharin, acesulfame potassium, erythritol, xylitol, sorbitol, and tagatose. Higher overall consumption was associated with faster declines in memory, language, and overall cognitive performance. The associations were also observed among participants without diabetes, suggesting the findings were not limited to people with existing metabolic disease.
The study does not prove that artificial sweeteners directly cause brain aging. Because it was observational, researchers say other lifestyle and health factors could contribute to the results despite statistical adjustments. They also note that dietary intake was based on self-reported food questionnaires, which has limitations.
Outside experts responding to the paper emphasized those limitations, arguing that different sweeteners have distinct biological effects and should not necessarily be grouped together. They also cautioned that the findings should be considered hypothesis-generating rather than definitive evidence of cause and effect. The study authors agreed that more research is needed but said the consistent associations across several sweeteners warrant further investigation.
For coffee drinkers, the research does not suggest abandoning coffee itself. Instead, it raises new questions about the long-term health effects of the artificial sweeteners commonly stirred into coffee, tea, diet beverages, and other low-calorie foods. Researchers say additional studies will be needed to determine whether reducing artificial sweetener intake could help preserve cognitive health over time.
