The safety of sugar substitutes is being questioned again.
Researchers from the Cleveland Clinic linked xylitol to higher risks of heart attack, stroke, or cardiovascular-related deaths. This study was published in the European Heart Journal today.
Xylitol is a sugar alcohol found in small amounts in fruits and vegetables. It’s also produced by the human body. Used as an additive, it has 40% fewer calories than sugar but tastes similar. It’s common in sugar-free gum, candies, toothpaste, and baked goods, especially in Europe.
Last year, the same team found a similar risk with erythritol, another sugar substitute. Sugar substitutes have become more popular as obesity concerns rise.
“We’re adding this to our diets, and those most likely to consume it are at higher risk,” said Dr. Stanley Hazen, the study's lead author. He’s the chair of cardiovascular and metabolic sciences at Cleveland Clinic’s Lerner Research Institute.
Many heart attacks and strokes happen to people without known risk factors like diabetes or high blood pressure. The research team looked at sugar alcohols in the body to see if they could predict cardiovascular risk.
In their study, they measured naturally occurring xylitol in over 3,000 participants after fasting. Those with the highest xylitol levels had double the risk of heart attack, stroke, or death in three years compared to those with the lowest levels.
The team also explored the mechanisms by feeding xylitol to mice and adding it to blood in a lab. They gave a xylitol drink to 10 healthy volunteers. Xylitol activated platelets, which are key in blood clotting, said Hazen. Blood clots are the main cause of heart attacks and strokes.
“Xylitol interacts with platelets very briefly, making them more prone to clot,” Hazen explained.
Dr. Sadiya Khan from Northwestern Medicine noted that we need to understand why xylitol levels are higher in some people and how to reduce them. She emphasized the need for more research.
Until then, Hazen advises avoiding xylitol and other sugar alcohols ending in ‘itol’. He suggests using small amounts of sugar, honey, or fruit to sweeten food. Toothpaste and one stick of gum likely don’t pose a problem due to low xylitol intake.
The study has limitations. It’s observational and only shows a link, not causation, between xylitol and heart risk.
Despite these limitations, Dr. Khan suggests limiting artificial sweeteners. She advocates for natural sugars from high-quality foods like fruits and vegetables instead.
Artificial sweeteners are easy to avoid, says Joanne Slavin, a professor of nutrition. They are listed in ingredient lists on packaged goods.
“Should people avoid xylitol completely?” Slavin asks. She believes that sugar substitutes can help those struggling to reduce sugar. It’s a personal choice.
Slavin found the study interesting but noted that sugar alcohols are usually used in small amounts in products like gum and candies. They are expensive and used sparingly.
Another study limitation is that the participants had high heart disease risk. Thus, the results might not apply to healthy people.
Still, many middle-aged and older Americans share the study participants' characteristics, says Hazen. “Obesity, diabetes, high cholesterol, or high blood pressure are common,” he added.