A recent study published in the medical journal Neurology has found a concerning association between the consumption of seven common artificial sweeteners and a faster rate of cognitive decline, particularly in middle-aged adults. The research suggests that regular intake of these low- and no-calorie sweeteners may contribute to long-term harm to cognitive function, equivalent to accelerated brain aging.
Key Findings of the Cognitive Decline Study
The extensive study, which tracked over 12,700 adults in Brazil for an average of eight years, investigated the impact of seven specific sweeteners: aspartame, saccharin, acesulfame-K, erythritol, sorbitol, xylitol, and tagatose. Researchers observed that participants with the highest intake of these sweeteners experienced a 62% faster decline in overall thinking and memory skills compared to those with the lowest consumption. This accelerated decline was likened to approximately 1.6 additional years of brain aging.
Sweeteners Implicated in Cognitive Decline
Of the seven sweeteners examined, all except tagatose were linked to cognitive loss, specifically impacting memory and verbal fluency. The sweeteners found to be associated with faster cognitive decline include:
- Aspartame
- Saccharin
- Acesulfame-K (Acesulfame potassium)
- Erythritol
- Sorbitol
- Xylitol
The study noted that these sweeteners are frequently found in ultra-processed foods such as diet sodas, flavored waters, energy drinks, yogurts, and low-calorie desserts.
Age and Diabetes as Amplifying Factors
A particularly striking finding was that the link between artificial sweetener use and cognitive decline was most pronounced in adults under the age of 60. This suggests that exposure during midlife could have significant, long-term consequences for brain health, even before cognitive symptoms typically manifest.
Furthermore, the study revealed that the association with faster cognitive decline was stronger in individuals with diabetes than in those without the condition. This is a critical observation, given that people with diabetes often turn to artificial sweeteners as sugar substitutes.
The Broader Context of Artificial Sweeteners and Health
While artificial sweeteners are often promoted as healthier alternatives to sugar for weight management and blood sugar control, a growing body of research is raising concerns about their potential long-term effects beyond just cognitive function. Previous studies have suggested links to an increased risk of type 2 diabetes, cancer, heart problems, depression, and dementia, as well as potential damage to the gut wall.
Some research indicates that artificial sweeteners like aspartame, sucralose, and saccharin can lead to oxidative stress and neuroinflammation, disrupt the blood-brain barrier, and alter cerebral blood flow, all of which could contribute to cognitive decline. Additionally, they may disrupt the gut microbiome and impair the gut-brain axis, further exacerbating neurocognitive issues. A separate study also found that sucralose can alter brain activity related to hunger and increase appetite, particularly in individuals with obesity.
Limitations and Future Research
It is important to note that this new study, while robust, shows an association and does not definitively prove that artificial sweeteners directly cause cognitive decline. Factors such as self-reported dietary intake and the absence of all types of sweeteners in the analysis are acknowledged limitations.
However, the findings warrant caution and call for further investigation. Researchers, including study author Prof. Claudia Kimie Suemoto of the University of São Paulo, emphasize the need for additional research, including brain imaging and mechanistic studies exploring gut health and inflammation, to fully understand the biological pathways involved. Her team is reportedly already engaged in neuroimaging studies to delve deeper into these potential causal links.
Recommendations for Consumers
Given the emerging concerns, the study’s researchers suggest that consumers might consider natural sweeteners like tagatose (which showed no link to cognitive decline in this study), honey, or maple syrup as alternatives. Public health strategies may need to be developed to educate consumers about the potential cognitive risks associated with artificial sweeteners and encourage a balanced approach to their consumption.
