How xylitol could increase cardiovascular risk
For a long time, the mood around xylitol was quite positive. Studies suggest this may change the composition of the oral microbiome – the populations of microbes in our mouths – in ways that protect our teeth.
Other studies have shown that it may reduce rates of respiratory infections and increase amounts of beneficial chemicals in the gut. Importantly, because xylitol results in lower glucose peaks and lower insulin production than sugar, it has been seen as a powerful tool for helping people lose weight.
However, over the past three years, Witkowski and other cardiology researchers at the Cleveland Clinic have published a series of studies linking xylitol and erythritol to cardiovascular problems.
This research linked high blood levels of erythritol or xylitol to heart attacks and strokes in a group of more than 1,100 people considered to be at higher risk of cardiovascular disease.
They also carried out further investigations, including a so-called human challenge study, in which 10 human volunteers agreed to ingest 30g of xylitol – the dose typically used in a can of soft drink – and have their blood sampled half an hour later.
The findings suggest that high concentrations of xylitol and erythritol in the blood could increase the risk of heart attack or stroke by activating tiny fragments of blood cells called platelets and encouraging them to clump together and form clots.
“We need to take these findings about sugar alcohols seriously,” says Professor Beer. “Especially since if you look at AI search engines and ask which sweeteners to use to replace sugar, some of them recommend erythritol as a first-line option.”
What else could be behind all this?
At the same time, other researchers point out that these results could have a very different explanation.
Professor Bettina Wölnerhanssen, professor at the University of Basel and co-lead of a research group on metabolism, points out that the body naturally produces xylitol and other sugar alcohols as a byproduct of glucose digestion.
High levels of xylitol in the blood may reflect excessive sugar consumption, an underlying metabolic disease, or prediabetes, which are known to increase the risk of stroke or heart attack over time.
Although the results of the human challenge trial were striking, Professor Wölnerhanssen also noted that platelets can temporarily clump together in response to a number of different behaviors, for example eating a salty soup, before returning to normal without lasting effects.
She says larger studies are needed to prove whether ingesting high doses of xylitol as a sweetener creates a risk of dangerous blood clots.
What should we do?
“These results should not be taken as a reason to choose conventional sugar (over sweeteners),” says Professor Wölnerhanssen. “I worry this will happen as people feel more anxious about xylitol, but the risks of excess sugar to the heart are much better documented.”
However, Professor Beer has a different view. He believes that the people who need to be most concerned about xylitol as a sweetener are those who already live with various chronic illnesses such as prediabetes, high blood pressure, high cholesterol, and those who have already had a heart attack.
This is because their risk of stroke or another heart attack is already high. If xylitol is capable of causing clots, he says consuming more of it through food and other products could exacerbate that risk.
People with liver disease “may also be more vulnerable, as they take longer to clear xylitol from the bloodstream, and there are more likely to be adverse effects”, says Professor Beer.
Professor Beer suggests that people living with these chronic illnesses might be advised to look for diet products flavored with other sweeteners, at least occasionally.
Although health concerns have been raised about artificial sweeteners like saccharin and aspartame, he believes the evidence linking sugar alcohols to possible harm is stronger.
“For these more vulnerable groups, you should try not to overdo it. If you’re consuming a lot, for example several cans of soft drinks containing xylitol, per day, it’s probably time to cut back.”
Gn Health
