The erythritol, a sweetener used in sugar-free products, disrupted several functions of cerebral vascular cells cultured in the laboratory. The results concern in particular blood vessel dilation, oxidative stress, and clot dissolution.
The team from the University of Colorado Boulder studied human cerebral microvascular endothelial cells. These cells line the small vessels that supply the brain. They participate in controlling blood flow and exchanges between the blood and brain tissues.
Erythritol - Image Wikimedia
The researchers exposed the cells for three hours to a concentration of 6 millimoles per liter of erythritol. According to the study, this value corresponds to the exposure expected after ingestion of about 30 g in a sweetened drink. Non-exposed cells served as a comparison group.
After this treatment, the production of reactive oxygen species almost doubled. These highly reactive molecules can damage cellular components when they become too abundant. The cells also increased certain antioxidant proteins, which indicates a defensive response to this stress.
Erythritol also modified the signals controlling the diameter of the vessels. The production of nitric oxide, a molecule promoting their dilation, decreased. The production of endothelin-1, which on the contrary contributes to their contraction, increased. Such an imbalance could affect cerebral blood flow.
Another experiment focused on tissue plasminogen activator, or t-PA. This protein helps the body dissolve blood clots. After stimulation with thrombin, cells exposed to erythritol released less t-PA than control cells.
These mechanisms are consistent with a less protective vascular function, but their clinical significance remains unknown. The study is based on a single cell line, a brief exposure, and a single concentration. It does not include digestion, metabolism, or elimination of the sweetener in a whole organism.
The authors consider that these observations could help explain associations already noted between elevated concentrations of erythritol in the blood and certain cardiovascular events. Human trials remain necessary to determine the real effects of regular consumption, the doses involved, and potentially more vulnerable populations.