According to ScienceAlert, erythritol—the sweetener found in thousands of sugar-free and keto products—may be damaging the blood-brain barrier and significantly increasing stroke risk. University of Colorado researchers found that exposing blood-brain barrier cells to typical post-consumption erythritol levels triggered oxidative stress that killed cells and disrupted blood vessel function. The sweetener reduced nitric oxide production while increasing endothelin-1, creating dangerous blood vessel constriction that could starve the brain of oxygen. Even more alarming, erythritol blocked the body’s natural “clot buster” mechanism that normally dissolves blood clots before they cause strokes. These lab findings align with human studies showing people with highest erythritol blood levels face roughly double the risk of major cardiac events.
The brain’s security system under attack
Here’s the thing about the blood-brain barrier—it’s basically your brain’s bouncer. It decides what gets in and what stays out, protecting your most vital organ from harmful substances while letting nutrients through. When erythritol damages these cells, it’s like the bouncer’s taking a smoke break and letting anyone wander in. The study found erythritol floods cells with free radicals while simultaneously reducing antioxidant defenses. That’s a double whammy that either kills the cells outright or leaves them too damaged to do their job properly.
When your blood vessels stop cooperating
But the vascular effects might be even more concerning. Healthy blood vessels are constantly adjusting—widening during exercise when you need more blood flow, tightening when you’re at rest. Erythritol completely messes with this delicate balance. It reduces nitric oxide (the relaxer) while ramping up endothelin-1 (the constrictor). The result? Blood vessels that stay too tight, potentially starving the brain of oxygen. This exact imbalance is a known warning sign for ischemic stroke, which accounts for about 87% of all strokes according to the American Stroke Association.
Why this sweetener is everywhere
Erythritol occupies this weird middle ground in the sweetener world. Unlike artificial sweeteners like aspartame, it’s technically a sugar alcohol that occurs naturally in small amounts. That helped it avoid the WHO’s recent guidelines discouraging non-sugar sweeteners for weight control. Food manufacturers love it because it behaves more like real sugar than other alternatives—it’s only about 80% as sweet, making it easier to work with in recipes without creating that overpowering artificial taste. So it’s ended up in everything from protein bars to sugar-free candies to keto-friendly baked goods.
The safety approval problem
Now here’s where it gets tricky. Both the FDA and European Food Standards Agency have approved erythritol as safe. But most of the safety testing was done years ago, before we understood how it might affect these delicate cellular systems. The researchers acknowledge their study has limitations—it was done on isolated cells in lab dishes, not complete blood vessels in living humans. But when you combine these lab findings with those large observational studies showing doubled cardiac risk, you’ve got to wonder: are we trading sugar problems for vascular problems?
What should you actually do?
Look, I’m not saying panic and throw out every sugar-free product in your pantry. But this research does raise serious questions about frequent erythritol consumption. The sweetener can be genuinely helpful for weight management and diabetes prevention—helping people reduce calories and control blood sugar spikes. But if regular use is quietly compromising your brain’s protection over time, that’s a pretty significant trade-off. The full study in the Journal of Applied Physiology suggests we need much more sophisticated testing, maybe using those “blood vessel on a chip” systems that better mimic real human physiology.
The bigger picture
This isn’t just about erythritol—it’s about our whole approach to food additives. We introduce these substances into thousands of products, they get regulatory approval based on limited testing, and then years later we discover potential long-term risks. The research underscores how little we understand about how these compounds affect our most delicate biological systems over time. Maybe the lesson here is that when it comes to what we put in our bodies, “generally recognized as safe” doesn’t always mean “actually safe for frequent consumption over decades.”
