Xylitol is a sugar alcohol that is found in small amounts in fruit and vegetables and is used in sugar-free gum, toothpaste and baked goods.  The safety of sugar substitutes is once again being called into question.  Researchers linked the low-calorie sugar substitute xylitol to an increased risk of heart attack, stroke or cardiovascular-related deaths, according to a study published today in the European Heart Journal. 

Xylitol is a sugar alcohol that is found in small amounts in fruit and vegetables, and the human body also produces it.  As an additive, it looks and tastes like sugar but has 40% fewer calories.  It is used at much higher concentrations than found in nature, in sugar-free gum, candies, toothpaste and baked goods. It can also be found in products labeled "keto-friendly”.  The same research team found a similar association last year to the popular sugar substitute erythritol.  The use of sugar substitutes has increased significantly over the past decade as concerns about rising obesity rates mount.  “We’re throwing this stuff into our food pyramid, and the very people who are most likely to be consuming it are the ones who are most likely to be at risk” of heart attack and stroke, such as people with diabetes, said lead author Dr. Stanely Hazen, chair of cardiovascular and metabolic sciences at Cleveland Clinic’s Lerner Research Institute. 

Many heart attacks and strokes occur in people who do not have known risk factors, like diabetes, high blood pressure or elevated cholesterol levels.  The research team began studying sugar alcohols found naturally in the human body to see if the compounds might predict cardiovascular risk in these people.  In the study, the investigators measured the level of naturally occurring xylitol in the blood of more than 3,000 participants after overnight fasting.  They found that people whose xylitol levels put them in the top 25% of the study group had approximately double the risk for heart attack, stroke or death over the next three years compared to people in the bottom quarter. 

The researchers also wanted to understand the mechanism at work, so they fed xylitol to mice, added it to blood and plasma in a lab and gave a xylitol-containing drink to 10 healthy volunteers.  In all these cases, xylitol seemed to activate platelets, which are the blood component that controls clotting, said Hazen.  Blood clots are the leading cause of heart attack and stroke.  “All it takes is xylitol to interact with platelets alone for a very brief period of time, a matter of minutes, and the platelet becomes supercharged and much more prone to clot,” Hazen said.  In the meantime, he is telling patients to avoid eating xylitol and other sugar alcohols, whose spelling all end in ‘itol.’  Instead, he recommends using modest amounts of sugar, honey or fruit to sweeten food, adding that toothpaste and one stick of gum are probably not a problem because so little xylitol is ingested.