Do Sugar Substitutes Affect Your Brain? What a Big Study Found

What the Study Is About

A new study published in Neurology (a medical journal from the American Academy of Neurology) looked at whether sugar substitutes might be linked to faster drops in memory and thinking skills over time.

Researchers followed nearly 13,000 adults and studied seven sweeteners that have few or no calories. They found that people who ate the most of these sweeteners showed quicker declines in brain skills than those who ate the least. This link was especially strong in people with diabetes.

Important Point: The study does NOT prove that sweeteners directly cause brain decline. It only shows a connection. Other things could explain the pattern.

Seven Common Sweeteners Examined

The researchers studied these seven sweeteners:

• Aspartame
• Saccharin
• Acesulfame K
• Erythritol
• Xylitol
• Sorbitol
• Tagatose

These are often added to ultra-processed foods like:

• Flavored water
• Soft drinks
• Energy drinks
• Yogurt
• Desserts labeled "low calorie"

Some are also sold on their own for coffee, tea, cooking, or baking.

As study author Dr. Claudia Kimie Suemoto said: "Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar, however our findings suggest certain sweeteners may have negative effects on brain health over time."

Tracking Brain Health for Eight Years

Here is how the study worked:

1. Who: 12,772 adults in Brazil. Average age: 52 years.
2. How long: Followed for about 8 years.
3. Food check: At the start, people filled out detailed food surveys about what they ate/drank in the past year.
4. Groups: Researchers split them into 3 groups by total sweetener intake.
   • Lowest group: ~20 mg/day
   • Highest group: ~191 mg/day (for aspartame, that’s about one can of diet soda)
5. Biggest single sweetener: Sorbitol, avg 64 mg/day per person.
6. Brain tests: Taken at start, middle, and end. They measured:
   • Verbal fluency (finding words quickly)
   • Working memory (short-term hold/use of info)
   • Word recall
   • Processing speed (how fast you understand/respond)

Higher Intake Linked to Faster Cognitive Decline

After adjusting for age, sex, blood pressure, heart disease, and more:

• Highest intake group declined 62% faster in thinking/memory than lowest group. That’s like 1.6 extra years of aging.
• Middle group declined 35% faster than lowest. That’s like 1.3 extra years of aging.

Stronger Association in Adults Under 60

Age mattered:

• Under 60: highest consumers declined faster in verbal fluency and overall brain performance.
• Over 60: no same link found.

The link was also stronger in people with diabetes. They often use substitutes because they’re told to avoid sugars that spike blood sugar.

Six Sweeteners Linked to Memory Changes

When looked at one by one, six were tied to faster overall cognitive decline (especially memory):

• Aspartame
• Saccharin
• Acesulfame K
• Erythritol
• Sorbitol
• Xylitol

Tagatose was the only one NOT linked to decline.

Dr. Suemoto noted: people with diabetes use these more, and we need more research on other alternatives like applesauce, honey, maple syrup, or coconut sugar.

Important Limits of the Research

• Not all artificial sweeteners were included.
• Diet info came from participants (they may forget or misjudge).
• It was observational: shows a relationship, not proof of cause.

Key Findings

• Studied 12,772 adults, avg age 52.
• Examined 7 sweeteners in sodas, yogurts, desserts, etc.
• Highest consumers declined faster in thinking/memory.
• Difference ≈ 1.6 years of extra aging.
• Link seen under 60, not over 60.
• Shows link, not proof of cause.

Funded by Brazilian Ministry of Health, Ministry of Science/Tech, and National Council for Scientific/Technological Development.

Summary

A large 8-year study of Brazilian adults found that eating more low-calorie sweeteners was linked to faster drops in memory and thinking, especially for those under 60 and with diabetes. Six of seven studied sweeteners showed this link; tagatose did not. But this is an observational study—it shows a connection, not proof that sweeteners cause harm. More research is needed.

FAQ

1. Does this mean I should stop using sweeteners?
Not necessarily. The study shows a link, not cause. Talk to a doctor if you’re concerned, especially if you have diabetes.

2. Which sweetener was safest for brain health in the study?
Tagatose was the only one not linked to cognitive decline.

3. Why were people with diabetes more affected?
They may use sweeteners more often as sugar replacements, and the study found a stronger link in that group.

4. Can kids or teens be affected?
The study looked at adults (avg 52). The under-60 group showed links, but kids were not studied.

5. What should I use instead of artificial sweeteners?
Researchers suggest studying applesauce, honey, maple syrup, or coconut sugar as alternatives, but more evidence is needed.