Diet Soda and Cognitive Health: New Research Insights

A recent study from Brazil has raised concerns about the impact of diet soda on cognitive health. It appears that consuming a lot of artificial sweeteners might lead to quicker declines in memory and thinking skills.

Published in the Journal of Neurology, the research showed that participants with high levels of artificial sweetener consumption experienced a “significantly faster reduction” in cognitive abilities. To put it in perspective, those in the highest-consuming group experienced about 1.6 extra years of brain aging, with 62% showing cognitive decline.

The risk was particularly notable among younger adults under 60 and individuals with diabetes. Interestingly, older adults over 60 didn’t seem to be as affected.

The study tracked 12,772 adults with an average age of 52 over an eight-year period. Participants filled out surveys about their dietary habits, focusing on the intake of seven different artificial sweeteners commonly found in sodas, energy drinks, flavored water, yogurts, and low-calorie desserts.

These sweeteners included aspartame, saccharin, acesulfame K, erythritol, xylitol, sorbitol, and tagatose. Those who used sweeteners typically consumed an average of 191 milligrams daily, compared to just 20 milligrams for those who consumed the least.

Cognitive tests conducted at various intervals during the study assessed memory, language, and thinking abilities. The findings were clear: all sweeteners, except tagatose, were linked to faster cognitive decline, especially in memory.

Claudia Kimmy Sumoto, a researcher from the University of Sao Paulo, emphasized the findings, saying that while more research is necessary, it’s essential to reconsider our use of sugar substitutes. She suggests that it might be best to limit both added sugars and artificial sweeteners, opting for more natural choices and maintaining a balanced diet.

“Our results suggest that middle-aged exposure to sweeteners can be particularly harmful,” Sumoto noted, highlighting that early cognitive decline often begins long before symptoms are evident. “Middle-aged exposure can accelerate these processes and have lasting effects.”

Given these results, researchers advise minimizing the intake of artificial sweeteners whenever possible, and ideally opting for whole fruit, honey, or maple syrup for sweetness. This would not only avoid potential risks but also promote a more natural diet.

Dr. Brintosa Vasagal, a family physician based in Milwaukee, shared her insights, suggesting that while some individuals may benefit from avoiding sugar altogether, natural sweeteners are often the better choice. She cautioned that artificial sweeteners can sometimes alter people’s taste perception, leading them to crave more sugar to achieve the same level of satisfaction.

“There’s a connection between artificial sweeteners and brain health, but we lack clear evidence of a causative link,” she added.

Most experts recommend keeping consumption of diet sodas to a minimum—ideally one drink per day or just every few weeks. Instead of reaching for diet soda, Vasagal suggests water infused with fruits or herbs for a refreshing alternative.

For those managing diabetes, she recommends collaborating with a physician to create a tailored dietary plan, stressing the need for moderation even with artificial sweeteners, which can impact blood sugar levels.

Study Limitations and Need for Further Research

The researchers were open about the study’s limitations. They acknowledged that dietary assessments occurred only at the start of the study, and while they accounted for various factors, there might still be some residual confounding. The study did not cover all types of artificial sweeteners, and relying on self-reported data can introduce inaccuracies.

Future research could delve deeper by utilizing different groups or techniques, such as neuroimaging, to explore if brain changes correlate with sweetener consumption.

Vasagal agreed on the necessity of further studies to determine whether artificial sweeteners directly contribute to cognitive issues. She reiterated, “It’s vital to understand the link between these sweeteners and brain health, but we still need data to establish a causal relationship.”

The Calorie Control Council also weighed in on the findings, asserting that low-calorie sweeteners have been deemed safe by health authorities. They pointed out that the study has significant shortcomings, primarily due to its reliance on initial self-reported dietary data, and cautioned against misinterpretations that may affect those who use artificial sweeteners for diabetes management.

This study received support from Brazil’s Ministry of Health, Ministry of Science, Technology and Innovation, and the National Council for Science and Technology Development.