A common sugar substitute found in diet drinks, protein bars and low-carb snacks may not be as harmless as we’ve been led to believe.
New research published in the Journal of Applied Physiology has found that erythritol, a popular non-nutritive sweetener, can impair the function of cells lining blood vessels in the brain in ways that may raise the risk of stroke.
According to data from the Australian Bureau of Statistics, 28.9 per cent of us reported consuming sweetened drinks, including sugar-free varieties, and nearly one in 10 people (9.6 per cent) consume beverages sweetened with artificial or alternative sweeteners rather than sugar.
Erythritol, first approved for use here in the late nineties, contains almost no calories and has minimal impact on blood glucose or insulin levels. For those managing weight, diabetes or carbohydrate intake, it has long been marketed as a safer alternative.
However, the study from scientists at the University of Colorado Boulder suggests the picture may be more complex.
Researchers exposed human cerebral microvascular endothelial cells – the cells that line the tiny blood vessels in the brain – to levels of erythritol comparable to what someone might consume in a typical sugar-free beverage.
They found that exposure to erythritol caused the cells to produce significantly less nitric oxide, a molecule that helps blood vessels relax and widen. At the same time, the cells produced more endothelin-1, a protein that constricts blood vessels.
The study also showed that when the cells were challenged with a clot-forming compound, their ability to produce t-PA – a natural clot-dissolving substance – was “markedly blunted”. In addition, erythritol exposure increased the production of reactive oxygen species, also known as free radicals, which can damage cells and contribute to inflammation.
Senior author Professor Christopher DeSouza, director of the Integrative Vascular Biology Lab, said: “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.”
“Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” added co-author, Auburn Berry.
Stroke occurs when blood supply to part of the brain is interrupted, either due to a clot or a ruptured blood vessel. Healthy endothelial cells, which line blood vessels, play a crucial role in regulating blood flow, preventing excessive clotting and maintaining vascular flexibility.
If those cells become dysfunctional, blood vessels may constrict more readily, and clots may be more likely to form or less likely to dissolve. The changes observed in this study provide a possible explanation for earlier research that linked higher levels of erythritol with increased cardiovascular events.
It’s worth noting that this was a lab study conducted in cells, not a clinical trial in humans. The researchers emphasise that more research is needed to determine how these findings translate to real-world consumption patterns and long-term health outcomes.
Still, Professor DeSouza urged caution. “We believe it would be prudent for people to monitor their consumption of non-nutrient-sweeteners such as this one.”
For those of us who regularly choose sugar-free options in an effort to reduce calories or manage blood sugar, the findings may prompt a rethink. While erythritol is still considered safe by food regulators, this study suggests that ‘sugar-free’ does not necessarily mean risk-free.
