...
By Hannah Millington
Health Reporter
0
Share
Newsweek is a Trust Project member
See more of our trusted coverage when you search.Prefer Newsweek on Googleto see more of our trusted coverage when you search.
Some artificial sweeteners may come with unexpected consequences for long-term brain health.
This is the warning of researchers in Brazil who studied the consumption of seven artificial sweeteners typically found in ultra-processed foods like flavored water, soda, energy drinks, yogurt and low-calorie desserts.
They discovered that people who consumed the highest amounts of the sweeteners experienced faster declines in thinking and memory skills compared to those who consumed the lowest amounts.
Read More on Health
Furthermore, this association appeared to be stronger in people with diabetes.
The sugar substitutes and sugar alcohols examined in the study were acesulfame-K, aspartame, erythritol, saccharin, sorbitol, tagatose and xylitol, which are both found in certain food products and used as standalone sweeteners.
"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 in a statement.
...
The study included 12,772 adults from across Brazil, who at the start of the study were both aged between 35 and 74 years and free of dementia. The average age was 52 and participants were followed for an average of eight years.
Each subject completed questionnaires about their diet at the start of the study, detailing what they ate and drank over the past year. Researchers then divided them into three groups based on the total amount of artificial sweeteners they consumed.
The lowest group consumed an average of 20 mg per day and the highest group consumed an average of 191 mg a day. For the sweetener aspartame, the higher amount is equivalent to one can of diet soda.
Sorbitol had the highest consumption, with an average of 64 mg a day.
...
Participants were given cognitive tests at the start, middle and end of the study to track memory, language and thinking skills over time. The tests assessed areas such as verbal fluency, working memory, word recall and processing speed.
After adjusting for factors including age, sex, high blood pressure and cardiovascular disease, the researchers found that people who consumed the highest amount of sweeteners showed a 62 percent faster decline in overall thinking and memory skills than those who consumed the lowest amount.
This is the equivalent of about 1.6 years of aging, according to the team.
Those in the middle group had a decline that was 35 percent faster than the lowest group, equivalent to about 1.3 years of aging.
"We hypothesize that artificial sweeteners may trigger processes such as neuroinflammation, neurodegeneration, or disruption of the gut–brain axis," Suemoto told Newsweek.
*"*For example, animal studies suggest that aspartame can lead to neuroinflammation, while sugar alcohols like erythritol and sorbitol may alter the gut microbiota and compromise the blood–brain barrier.
"These mechanisms could make the brain more vulnerable over time, particularly when exposure begins in midlife."
The researchers also found that people under the age of 60 who consumed the highest amounts of sweeteners showed faster declines in verbal fluency and overall cognition when compared to those who consumed the lowest amounts. They did not find links in people over 60.
Noting that this finding came as a surprise, Suemoto added: "This emphasizes the importance of understanding dietary habits earlier in adulthood, when preventive strategies could have the greatest impact."
Notably, they also found the link to faster cognitive decline was stronger in participants with diabetes than in those without diabetes.
When looking at individual sweeteners, consuming acesulfame-K, aspartame, erythritol, saccharin, sorbitol and xylitol was associated with a faster decline in overall cognition, particularly in memory. They found no link between the consumption of tagatose and cognitive decline.
"While we found links to cognitive decline for middle-aged people both with and without diabetes, people with diabetes are more likely to use artificial sweeteners as sugar substitutes," Suemoto emphasized.
The authors note that not all artificial sweeteners were included in the study and diet information reported by the participants may not have been remembered 100 percent accurately.
While the study shows a link between the use of some artificial sweeteners and cognitive decline, they also point out it does not prove they were the cause.
"Our findings suggest the possibility of long-term harm from consumption of LNCSs [low- and no-calorie sweeteners], particularly artificial LNCSs and sugar alcohols, on cognitive function. Therefore, opting for natural sweeteners, such as tagatose, or other sugar alternatives may help mitigate the potentially harmful association observed," the study authors wrote in the paper.
"Future research is needed to confirm our findings and to investigate whether other refined sugar alternatives, such as applesauce, honey, maple syrup or coconut sugar, may be effective alternatives to avoid the detrimental association between LNCS consumption and cognitive function."
Suemoto also said that they should work on determining how to compare artificial sweeteners with regular sodas and desserts.
Do you have a tip on a health story that Newsweek should be covering? Do you have a question about sweeteners? Let us know via health@newsweek.com.
Update 09/04/25, 06:37 a.m. ET: This article was updated with additional comments from Dr. Claudia Kimie Suemoto.
Reference
Gonçalves, N. G., Martinez-Steele, E., Lotufo, P. A., Bensenor, I., Goulart, A. C., Barreto, S. M., Giatti, L., de Faria, C. P., Molina, M. C. B., Caramelli, P., Marchioni, D. M., & Suemoto, C. K. (2025). Association between consumption of low- and no-calorie artificial sweeteners and cognitive decline: An 8-year prospective study. Neurology, 105(7). https://doi.org/10.1212/WNL.0000000000214023
View 0 Comments
Submit Correction
View Editorial & AI Guidelines