Recent research published in the scientific journal Neurology has established a concerning link between the consumption of sugar substitutes and accelerated cognitive decline in adults. The study, which involved 12,772 Brazilian participants, suggests that while these sweeteners may offer certain health benefits over traditional sugar, their long-term effects on cognitive function warrant attention.
The research team followed participants for nearly eight years, assessing their cognitive function at various intervals. The average age of participants was 52 years, with a demographic composition of 55% women and 43% Black or mixed race. Initially, the study recorded participants’ sugar substitute intake through detailed questionnaires covering their dietary habits over the past year.
In classifying the participants based on their daily intake of sugar substitutes, the researchers identified three categories: low (average of 20 milligrams (mg) per day), medium (average of 66 mg), and high (average of 191 mg). The findings revealed that those in the highest intake category experienced a 62% faster decline in overall cognitive function compared to those in the lowest category. This difference equates to approximately 1.6 years of aging. Participants in the medium intake category also showed a decline of 35%, roughly equivalent to 1.3 years of aging.
Impacts on Specific Cognitive Functions
The study further examined specific cognitive areas, revealing that participants with the highest sugar substitute intake experienced a 32% decline in memory and a staggering 110% decline in verbal fluency for the medium intake group, with the high intake group showing an even greater drop of 173%. Notably, this trend was particularly pronounced among participants under 60 years old, especially those diagnosed with diabetes.
The researchers investigated individual sugar substitutes, including aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose. They found that six of the seven substitutes, notably aspartame and saccharin, were correlated with faster cognitive declines. Tagatose was the only substitute that did not show a similar association.
Christine Byrne, MPH, RD, a dietitian and owner of Ruby Oak Nutrition in Raleigh, North Carolina, highlights the complexity of nutrition, stating, “This is yet another example that proves nutrition is complicated, and many food choices come with pros and cons.” While acknowledging that sugar substitutes can aid in blood sugar control and reduce added sugar intake, she warns of potential downsides, including the risk of cognitive decline.
Understanding the Correlation
The researchers caution that the association observed does not imply that sugar substitutes directly cause cognitive decline. Instead, the findings indicate a correlation between higher intake and deteriorating cognitive health. Byrne notes that the study raises important questions about the mechanisms behind the observed effects, suggesting that sugar substitutes might produce toxic metabolites during digestion that could contribute to inflammation in the brain.
This study is not the first to raise concerns regarding the effects of sugar substitutes on cognitive health. Previous research has found associations between artificially sweetened products and cognitive impairments, including diminished memory and executive function, alongside an increased risk of dementia.
While these findings prompt important discussions about the long-term effects of sugar substitutes, they do not necessarily render these sweeteners harmful across the board. For many, completely eliminating sugar substitutes may be impractical given their prevalence in numerous food and beverage products, especially in low-calorie options such as soft drinks, light yogurt, and flavored water.
Byrne advises consumers to be mindful of their intake, particularly if they regularly consume multiple artificially sweetened products. “If someone is drinking several diet sodas or other artificially-sweetened things per day, they might take this as a sign to cut back,” she suggests. Nonetheless, she emphasizes that this study should not incite panic about occasional consumption of artificial sweeteners.
As the conversation around dietary choices continues, this study underscores the necessity for further research to explore the intricate relationship between sugar substitutes and cognitive health.
