Artificial Sweeteners and Brain Health: What Parkinson’s and Dementia Patients Should Know

By Dr. Alex Armitage, DNP, CNL, APRN, FNP-BC, Passionate advocate for holistic well-being.

TOPLINE: New research links artificial sweeteners to faster cognitive decline. Learn safer alternatives for Parkinson’s and dementia care.

I woke this morning and crawled into my chair with a good cup of coffee to review the latest medical literature for the week, and there it was: an article on artificial sweeteners and brain health. My heart sank a little. Over the last few years, I’ve watched as our nation has become obsessed with weight loss, new diet drugs, and quick fixes for obesity. And yet, people aren’t getting healthier. In fact, in many ways, they’re getting sicker.

Here’s the truth I tell my patients: moving away from the taste of sweet—whether it’s sugar or artificial substitutes—is one of the hardest health changes you’ll ever make. Harder than climbing Mount Kilimanjaro. And I should know—I’ve climbed it! But it’s also one of the most important. Because every shortcut, every “trick” we use to keep things sweet without calories, is landing us in hotter water than we realize.

I mentally go through the list of people I know and care about who use artificial sweeteners, and I frown, wishing the data were different. However, the evidence is quite convincing, and I don't want them to suffer from something that could be avoided.

So let’s talk about one of the most widely used “solutions” for cutting calories: artificial sweeteners. And let’s talk about what the newest research says about how they affect the brain, especially for those living with Parkinson’s disease or dementia.

The New Research: A Wake-Up Call

A large study published this month in Neurology followed more than 12,000 adults for eight years and found that people who consumed more artificial sweeteners had a faster decline in memory, word-finding, and overall thinking skills compared to those who consumed little or none.

The culprits? Aspartame, saccharin, acesulfame K, erythritol, sorbitol, and xylitol. These are the very sweeteners hiding in “sugar-free” diet sodas, protein bars, yogurt cups, gum, and countless other foods on grocery store shelves. Interestingly, one natural sweetener, tagatose, did not show the same harmful effect.

This isn’t a small or trivial finding. The changes researchers saw in people who regularly consumed artificial sweeteners were equivalent to an extra year or more of brain aging over the study period. That’s huge when we think about diseases that already steal cognitive function like Parkinson’s and dementia.

Why This Matters: Parkinson’s or Dementia Brain Health

Parkinson’s disease and dementia both involve changes to memory, processing, and communication. In Parkinson’s, people may notice word-finding difficulties or slower thinking years before motor symptoms progress. Dementia, of course, directly impacts memory and daily function.

Now, imagine adding fuel to that fire with something as common as your “sugar-free” soda. Research suggests artificial sweeteners may:

• Trigger inflammation in brain cells. Aspartame, for example, breaks down into compounds that can irritate brain tissue.

• Disrupt the gut–brain connection. The bacteria in our gut play a huge role in brain health. Artificial sweeteners can disturb this balance, leading to problems with blood sugar and inflammation.

• Weaken the brain’s protective barrier. Some studies in animals suggest sweeteners may make the blood–brain barrier more “leaky,” allowing harmful substances to get in.

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For someone already facing cognitive changes, even small accelerations in decline can make a meaningful difference in independence and quality of life.

Diabetes: A Double Whammy

The study also found that people with diabetes were hit even harder. If you live with both Parkinson’s or dementia and diabetes, this matters. Many with diabetes reach for diet sodas or sugar-free treats thinking they’re making the safer choice. But the research showed that those with diabetes who consumed aspartame, saccharin, or acesulfame K had a significantly faster decline in memory and overall cognition.

This creates a cruel dilemma: the very people trying to control their blood sugar may be unintentionally harming their brain health.

What I Tell My Patients ...

This is the part where I pull up a chair and get real with people:

• Read the labels. If it says “sugar-free” or “low-calorie,” it probably contains one of these artificial sweeteners.

• Cut back slowly. Going cold turkey is hard. I know. But reducing gradually makes it doable.

• Choose natural options. If you need a touch of sweetness, try stevia, monk fruit, or tagatose. These appear to be safer choices and may help avoid the risks seen with artificial sweeteners and sugar alcohols.

• Shift your taste buds. Reducing sugar and processed carbs is harder than climbing Mount Kilimanjaro. BECAUSE IT IS. But the reward is worth it: eventually, natural foods like berries or nuts begin to taste sweet on their own.

• Go back to basics. A Mediterranean-style diet—with vegetables, berries, olive oil, nuts, and fish—has consistently been shown to support brain health and reduce dementia risk.

  
  

My Takeaway on Artificial Sweeteners and Brain Health

For years, we’ve been chasing the dream of “sweet without the consequences.” But this new research tells us that the consequences are real—just hidden. For those living with Parkinson’s or dementia, or caring for someone who is, the cost of keeping “sweet” in the diet may simply be too high.

That doesn’t mean you can never enjoy something sweet again. It means we need to be intentional about what we choose. If you must use a sweetener, reach for natural options like stevia, monk fruit, or tagatose—and skip the artificial ones.

I don’t say this to scare you. I say it to empower you. Every meal, every sip, every grocery-store choice is a chance to protect your brain. Choosing whole foods, dialing down the artificial, and giving your brain what it truly needs isn’t glamorous. But it just might help preserve the memories, the conversations, and the connections that matter most.

And to me—that’s worth far more than a sugar-free soda.

References

• Gonçalves, N. G., Martinez-Steele, E., Lotufo, P. A., Bensenor, I., Goulart, A. C., Barreto, S. M., Giatti, L., de Faria, C. P., Molina, M. C. B., Caramelli, P., Marchioni, D. M., & Suemoto, C. K. (2025). Association between consumption of low- and no-calorie artificial sweeteners and cognitive decline: An 8-year prospective study. Neurology, 105(7), e214023. https://doi.org/10.1212/WNL.0000000000214023 

• Pase, M. P., Himali, J. J., Beiser, A. S., et al. (2017). Sugar- and artificially sweetened beverages and the risks of incident stroke and dementia: A prospective cohort study. Stroke, 48(5), 1139–1146. https://doi.org/10.1161/STROKEAHA.116.016027

• Dar, W. (2024). Aspartame-induced cognitive dysfunction: Unveiling role of microglia-mediated neuroinflammation. International Immunopharmacology, 135, 112295. https://doi.org/10.1016/j.intimp.2024.112295

• Squizani, S., Jantsch, J., Rodrigues, F. D. S., et al. (2022). Zinc supplementation partially decreases the harmful effects of a cafeteria diet in rats but does not prevent intestinal dysbiosis. Nutrients, 14(19), 3921. https://doi.org/10.3390/nu14193921

• World Health Organization. (2019). Risk reduction of cognitive decline and dementia: WHO guidelines. World Health Organization. https://apps.who.int/iris/handle/10665/312180