Study Links Artificial Sweeteners to Faster Cognitive Decline

Researchers find higher consumption of common sweeteners may accelerate memory and thinking issues.

Jan. 30, 2026 at 12:23pm

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A new study published in the journal Neurology has linked higher consumption of artificial sweeteners like aspartame, saccharin, and erythritol to a faster rate of cognitive decline. The research followed over 12,000 adults for about 8 years and found that those with the highest artificial sweetener intake had a 62% faster decline in memory, language, and thinking skills compared to those with the lowest intake - the equivalent of about 1.6 years of aging. The effect was even more pronounced in people with diabetes.

Why it matters

This study raises concerns about the potential long-term cognitive impacts of regularly consuming common artificial sweeteners, which are found in many diet drinks, baked goods, and other processed foods. While more research is needed to establish a direct causal link, the findings suggest these sweeteners may trigger inflammation or disrupt the gut-brain connection in ways that accelerate age-related mental decline.

The details

The study divided participants into three groups based on their daily artificial sweetener intake. Those in the highest group consumed an average of 191 milligrams per day, about the amount in a can of diet soda. Researchers linked six specific sweeteners to the faster cognitive decline: aspartame, saccharin, acesulfame-K, erythritol, sorbitol, and xylitol. The effect was most pronounced in participants with diabetes, who already face a higher risk of cognitive issues.

  • The study followed participants for about 8 years, from the start of the study to the end.
  • Participants underwent cognitive testing at the beginning, middle, and end of the 8-year study period.

The players

Claudia Kimie Suemoto, M.D., Ph.D.

Study co-author and an associate professor at the University of São Paulo in Brazil.

Clifford Segil, D.O.

A neurologist at Providence Saint John's Health Center in Santa Monica, California.

Keri Gans, R.D.N.

Author of The Small Change Diet.

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What they’re saying

“Our hypothesis is that artificial sweeteners may trigger processes such as neuro-inflammation, neuro-degeneration, or disruption of the gut–brain axis based on animal models.”

— Claudia Kimie Suemoto, M.D., Ph.D., Study co-author and associate professor at the University of São Paulo

“These artificial sweeteners do not provide old-fashioned sugar or glucose into your body that is needed to be broken down in your body for energy and normal brain function.”

— Clifford Segil, D.O., Neurologist at Providence Saint John's Health Center

“Using sweeteners occasionally is not something most people need to worry about.”

— Keri Gans, R.D.N., Author of The Small Change Diet

What’s next

The researchers plan to conduct further studies to better understand the potential mechanisms by which artificial sweeteners may impact cognitive function, especially in populations with diabetes.

The takeaway

This study suggests that regularly consuming high amounts of common artificial sweeteners like those found in diet sodas, baked goods, and other processed foods may accelerate age-related cognitive decline, particularly for those with diabetes. While more research is needed, limiting intake of these sweeteners and focusing on whole, nutrient-dense foods may help support long-term brain health.