A Brazilian study published in Neurology followed 12,772 adults with an average age of 52 for eight years and found that six common artificial sweeteners were linked to faster cognitive decline. Participants with the highest intake experienced a 62 percent faster drop in memory and thinking abilities, equivalent to roughly 1.6 years of extra brain aging. The strongest associations appeared in adults under 60 and in people with diabetes.
What the study measured
Researchers divided participants into groups based on their daily consumption of artificial sweeteners. The highest-intake group averaged 191 milligrams per day, while the lowest averaged 20 milligrams. Across this gap, the high-consumption group showed a 62 percent faster decline in overall cognition, with particularly steep losses in memory.
Six of the seven sweeteners analyzed were tied to faster declines. The flagged sweeteners were aspartame, acesulfame-K, erythritol, saccharin, sorbitol, and xylitol. Only tagatose, a less common sugar substitute, showed no measurable association with cognitive problems. A separate drop in verbal fluency was linked to total sweetener intake rather than to any single sweetener.
Who was most affected?
The strongest signal appeared in participants younger than 60. The same pattern did not show up in adults over 60, a result one Harvard neurologist called "curious." Researchers suspect this may simply reflect the difficulty of detecting subtle changes in a population where natural age-related decline varies widely, not that sweeteners stop mattering after 60.
People with diabetes also showed a pronounced link between sweetener consumption and faster cognitive decline. That finding tracks with the fact that people with diabetes are often steered toward sugar substitutes. Importantly, the study also found the same association in people without diabetes, suggesting the effect is not limited to those with metabolic conditions.
Does correlation equal causation here?
No. The researchers note this was an observational study, meaning it identified a relationship between sweetener intake and brain aging but cannot prove that sweeteners directly cause the decline. Other lifestyle factors could contribute to the pattern.
That said, the consistency of the data raises questions about the long-term safety of widely consumed sweeteners. Some researchers have hypothesized that artificial sweeteners may alter the gut microbiome, promote inflammation, and trigger oxidative stress, all of which can affect brain function over time. Swapping diet soda for regular soda is not a clear fix either, as sugars such as fructose and sucrose carry their own dementia risk.
What researchers are saying
"Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar," said study author Claudia Kimie Suemoto, MD, PhD, of the University of São Paulo in Brazil. "However, our findings suggest certain sweeteners may have negative effects on brain health over time."
The study was supported by the Brazilian Ministry of Health and other national research bodies. The authors call for confirmation through additional studies.
Where these sweeteners appear
Aspartame, acesulfame-K, erythritol, saccharin, sorbitol, and xylitol are common in diet sodas, flavored waters, energy drinks, yogurts, and many low-calorie packaged snacks. Reading ingredient labels is the simplest way to identify which products contain them.
FAQ
Which artificial sweeteners were linked to faster brain aging?
The study tied six sweeteners to faster cognitive decline: aspartame, acesulfame-K, erythritol, saccharin, sorbitol, and xylitol. Tagatose was the only sweetener tested that showed no association.
How much faster was cognitive decline in high consumers?
Participants with the highest sweetener intake experienced a 62 percent faster decline in overall thinking and memory compared with the lowest-intake group, equivalent to roughly 1.6 years of extra brain aging.
Does this study prove artificial sweeteners cause cognitive decline?
No. The study was observational and identified a correlation, not a direct cause. The authors say the findings require confirmation through additional research.
Related coverage
This article summarizes reporting from naturalnews.com.
