A new study published in Neurology, the medical journal of the American Academy of Neurology, suggests that high consumption of low-calorie sweeteners may accelerate cognitive decline. Researchers found that adults who consumed the most artificial sweeteners experienced significantly faster declines in memory and thinking skills compared to those with the lowest intake.
The study analyzed data from 12,772 adults in Brazil. Participants were an average of 52 years old at the start of the research and were followed for approximately eight years. At the beginning of the study, participants completed detailed dietary questionnaires to estimate their daily intake of seven common sweeteners: aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose.
High Intake Linked to 62% Faster Decline
Participants were divided into three groups based on their consumption levels. The lowest group averaged 20 milligrams per day, while the highest group averaged 191 milligrams per day. To put that in perspective, 191 milligrams of aspartame is roughly equivalent to the amount found in one can of diet soda.
After adjusting for factors such as age, sex, high blood pressure, and cardiovascular disease, researchers determined that those in the highest consumption group experienced a 62% faster decline in overall thinking and memory abilities. This difference was equivalent to approximately 1.6 additional years of cognitive aging over the study period. Those in the middle consumption group showed a 35% faster decline, or about 1.3 additional years of cognitive aging.
Sorbitol had the highest average intake among the seven sweeteners examined, at 64 milligrams per day. Sorbitol is a sugar alcohol commonly used in sugar-free products. Six of the seven sweeteners studied were associated with faster declines in overall cognitive performance, particularly memory. Tagatose was the only exception, with no observed association with cognitive decline in this specific study.
Stronger Effects in Younger Adults and Diabetics
The link between sweetener consumption and cognitive health was not uniform across all participants. The association was particularly pronounced among adults younger than 60. In this age group, higher sweetener intake was linked to faster declines in verbal fluency and overall cognitive performance. Researchers did not find a similar association among participants older than 60.
The findings also highlighted a stronger relationship in people with diabetes. This is a significant observation because individuals with diabetes frequently use sugar substitutes to manage their sugar intake. Claudia Kimie Suemoto, MD, PhD, of the University of Sao Paulo in Brazil, led the study.
“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,” Suemoto said. “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.”
Study Limitations and Future Research
Researchers emphasized that the study shows an association rather than a proven cause-and-effect relationship. The observational design means that other unmeasured factors could contribute to the results. Additionally, dietary information relied on participants’ recollections, which may not perfectly reflect actual consumption habits due to memory errors or portion estimation issues.
The analysis did not cover every artificial sweetener available on the market, so the findings cannot be applied to all sugar substitutes. The research was supported by the Brazilian Ministry of Health, the Ministry of Science, Technology, and Innovation, and the National Council for Scientific and Technological Development.
Further studies are needed to confirm these findings and investigate whether other refined sugar alternatives, such as honey or maple syrup, produce different long-term outcomes. The research team noted that more work is required to understand why certain groups appear more strongly affected and whether the sweeteners themselves directly contribute to changes in brain function.
Source: ScienceDaily
