Brain cell research flags erythritol food additive may raise risk of stroke

New research reveals that the popular sugar substitute erythritol may affect brain cells in numerous ways that can raise the risk of stroke. The food additive is found across numerous low calorie foods, from low-carb ice cream to keto protein bars and sugar-free sodas. 

The sugar alcohol was first approved by the US FDA in 2001 and is produced by fermenting corn. It has close to no calories, around 80% of table sugar’s sweetness, and negligible impact on insulin levels, making it a favorite for people trying to lose weight, keep their blood sugar in check, or avoid carbohydrates.

“Our study adds to the evidence suggesting that non-nutritive sweeteners that have generally been purported to be safe, may not come without negative health consequences,” says senior author Christopher DeSouza, professor of integrative physiology and director of the US Integrative Vascular Biology Lab.

Higher chance of heart attack?

A previous Cleveland Clinic study involving 4,000 people in the US and Europe found that men and women with higher circulating levels of erythritol were significantly more likely to have a heart attack or stroke within the next three years.

In the current paper, DeSouza and first author Auburn Berry, a graduate student in his lab, investigated what could be driving that increased risk.

To test impacts of erythritol on cells, lab researchers treated human cells that line blood vessels in the brain for three hours with about the same amount of erythritol contained in a typical sugar-free beverage.

Brain cells treated with erythritol produced more free radicals.They observed that the treated cells were altered in numerous ways. Firstly, they expressed significantly less nitric oxide, a molecule that relaxes and widens blood vessels, and more endothelin-1, a protein that constricts blood vessels.

Meanwhile, when challenged with a clot-forming compound called thrombin, cellular production of the natural clot-busting compound t-PA was “markedly blunted.”

The erythritol-treated cells also produced more reactive oxygen species, also known as “free radicals,” which are metabolic byproducts that can age and damage cells and inflame tissue.

Previous research has shown that as little as 30 g of erythritol — around as much found in a pint of sugar-free ice cream — can also cause platelets, a component of blood, to clump together, potentially forming clots.

“Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” says Berry. “Our research demonstrates not only that, but how erythritol has the potential to increase stroke risk.”

Key considerations

DeSouza stresses that the study only used a serving-size worth of the sugar substitute.

His study suggests that for those who consume multiple servings per day, the impact could presumably be worse.

The authors caution larger studies in people are now needed, considering that their study was a laboratory study conducted on cells.

With that in mind, De Souza encourages consumers to consistently check labels, looking for erythritol or “sugar alcohol” on the label.

“Given the epidemiological study that inspired our work, and now our cellular findings, we believe it would be prudent for people to monitor their consumption of non-nutrient-sweeteners such as this one,” he concludes.

The University of Colorado Boulder study was published in the Journal of Applied Physiology.

In other recent research into sweeteners, a randomized crossover trial revealed that consuming sucralose instead of sugar increases activity in the hypothalamus brain region, which regulates appetite and hunger cues. It found that the sweetener also changes how the hypothalamus communicates with other brain parts, such as areas involved in motivation.

However, the International Sweeteners Association opposes this research, arguing that the study showed that sucralose had a neutral effect on appetite and hunger while triggering different brain responses compared to sugar-sweetened drinks. Speaking to Nutrition Insight, the association’s director general pointed to numerous studies that support the weight benefits of replacing sugar with low- or no-calorie sweeteners like sucralose.