A large Brazilian study published in Neurology followed nearly 13,000 adults for eight years and found something troubling: people who consumed the most artificial sweeteners showed faster cognitive decline compared to those who consumed the least.
The study tracked consumption of seven common artificial sweeteners: aspartame, saccharin, acesulfame K, erythritol, sorbitol, xylitol, and tagatose.
Participants who consumed the highest amounts showed:
32% faster decline in memory
173% faster decline in verbal fluency
62% faster decline in overall cognitive function
The effects were most pronounced in people under 60 and those with diabetes—two groups that often include patients managing chronic headaches and pain conditions.
Many of my patients unknowingly consume significant amounts of artificial sweeteners through:
Diet sodas and energy drinks
Sugar-free medications and supplements
Protein bars, protein powders and meal replacement shakes
“Diabetic-friendly” snacks for those managing medication-related weight gain
Low-calorie sports drinks are used during exercise therapy
For people already dealing with neurological symptoms, cognitive decline can significantly impact quality of life and treatment compliance.
The study found that artificial sweeteners had an even stronger negative effect on cognition in people with diabetes.
This is particularly relevant because many pain medications can affect blood sugar, chronic pain is linked to increased diabetes risk, and some headache preventive medications can cause weight gain, leading people to choose artificial sweeteners.
While this study can’t prove causation, researchers propose several mechanisms:
Neuroinflammation: Artificial sweeteners may trigger inflammatory responses in the brain, potentially worsening existing neurological conditions.
Gut microbiome disruption: These compounds can alter beneficial bacteria, which increasingly appear linked to brain health through the gut-brain axis.
Neurotoxic metabolites: Some artificial sweeteners break down into compounds that may directly damage brain cells.
So, instead of artificial sweeteners, try small amounts of natural sweeteners like honey or maple syrup, fresh or dried fruit to satisfy sweet cravings, and herbal teas instead of diet beverages.
Read labels carefully on pain relievers, migraine drugs that dissolve in your mouth, and supplements, especially those in gummies, protein powders, and “sugar-free” products.
While artificial sweeteners were once considered a harmless way to reduce calories, this research suggests they may carry hidden neurological risks. For people already managing headaches, chronic pain, or other neurological conditions, protecting cognitive function is crucial.
This doesn’t mean you need to panic if you occasionally consume artificial sweeteners, but it does suggest that making them a daily habit—especially in large amounts—may not be as safe as once thought.
