Popular sweeteners found in everyday drinks and low calorie snacks may carry a downside few people expect. A large new study has linked higher consumption of several widely used sweeteners to faster declines in memory and thinking skills over time, raising fresh questions about products long marketed as a healthier choice.
The research followed nearly thirteen thousand adults and examined seven common sweeteners containing little or no calories. People who consumed the largest total amounts experienced noticeably faster cognitive decline than those who consumed the least, and the pattern was especially pronounced among people living with diabetes. Researchers emphasized that this represents an association rather than definitive proof that these sweeteners directly cause the decline observed.
Seven common sweeteners under examination
The study examined a range of sweeteners commonly added to ultra processed products like flavored water, soft drinks, energy drinks, yogurt and reduced calorie desserts. Several also get sold individually for use in coffee, tea, cooking and baking at home.
One researcher involved in the work noted that these sweeteners are often viewed as a healthy alternative to sugar, yet the findings suggest certain substitutes may carry unexpected consequences for brain health over the long term.
Tracking brain health over eight years
Participants, whose average age was fifty two, were tracked for roughly eight years. At the outset, they completed detailed questionnaires describing their eating habits over the previous year, allowing researchers to divide them into three groups based on total sweetener intake. Those in the lowest group consumed far less daily than those in the highest group, with one common substitute reaching an amount roughly equivalent to what is found in a single can of diet soda among top consumers.
Throughout the study, participants completed cognitive assessments measuring several distinct mental skills, including how quickly they could retrieve words, how well they held information in short term memory, and how fast they processed new information.
Higher sweetener intake linked to faster decline
After accounting for age, sex, blood pressure, cardiovascular disease and other relevant health factors, researchers found a clear gap between consumption groups. Those consuming the highest amounts of sweeteners experienced cognitive decline roughly sixty percent faster than those consuming the least, a difference researchers compared to more than a year and a half of additional brain aging. A middle consumption group also showed meaningfully faster decline compared to the lowest group, though somewhat less pronounced.
Age and diabetes appeared to matter
The connection was notably stronger among adults younger than sixty, where higher sweetener intake was tied to faster decline in both word retrieval and overall cognitive performance. That same pattern did not appear among older participants. The association was also stronger among people with diabetes, a group that may rely on these products more heavily due to common advice to limit ingredients that spike blood sugar quickly.
When examined individually, six of the seven sweeteners studied showed a link to faster cognitive decline, particularly affecting memory. Only one showed no such association, suggesting the effect may not apply uniformly across every type of substitute on the market.
Understanding the limits of this research
The study did not include every sweetener currently available, meaning the findings cannot be generalized to every product on store shelves. Dietary information also came from self reporting, which carries inherent limitations since people do not always accurately recall what or how much they consumed.
Most importantly, this was an observational study. It identified a meaningful pattern between higher consumption and faster decline, but it cannot confirm that these ingredients are the actual cause. Researchers say further studies are needed, including comparisons with other sugar alternatives like honey, maple syrup or coconut sugar, before drawing firm conclusions about which sweeteners may be safest for long term brain health.
