Diet Soda may accelerate brain aging, new study suggests

Your favorite diet soda could be affecting your cognitive health, according to researchers in Brazil. A study published in Neurology found that participants who consumed the highest amounts of artificial sweeteners experienced a significantly faster decline in thinking and memory skills.

Key Findings

• Participants with the highest sweetener intake lost an average of 1.6 additional “brain years”, and the rate of cognitive decline was 62% higher than in low-consumption groups.

• The greatest risk was observed in people under 60 and those with diabetes. No significant changes were seen in participants over 60.

How the Study Was Conducted
The study included 12,772 adults with an average age of 52. Over eight years, participants completed surveys about their diet and beverage consumption and then took cognitive tests assessing memory, speech, and thinking skills.

Researchers examined seven artificial sweeteners commonly found in soda, energy drinks, yogurt, and low-calorie desserts: aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose. All except tagatose were linked to faster cognitive decline, particularly in memory.

Researchers’ Perspective

"Many consider artificial sweeteners a safe alternative to sugar, but our results suggest they may not be harmless, especially with regular consumption during midlife," said Claudia Kimi Suemoto from the University of São Paulo.

She emphasized that midlife is a critical period for brain health. “Cognitive decline and dementia begin decades before symptoms appear. Sweetener consumption during this period may accelerate these processes,” Suemoto added.

Public Recommendations

The study authors recommend reducing or avoiding artificial sweeteners. “Fruits, honey, or maple syrup in moderation are safer alternatives. They lower risks and promote a more natural, balanced diet,” Suemoto advised.

Family physician Dr. Brinta Vasagar of Milwaukee agrees: “While there’s an association between artificial sweeteners and brain health, there’s no evidence of a causal relationship. For most people, natural sugars in moderation are safer.” Diabetics are encouraged to consult their doctors for personalized dietary guidance.

Study Limitations

• Data relied on self-reported dietary intake collected only at the start of the study.

• Not all sweeteners were included, and participant recall may have been limited.

• Further research, including neuroimaging, is needed to confirm these findings.