If you’re watching your sugar intake, you’re probably already familiar with sugar-free packaged snacks and treats.
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The same flavor, but with no sugar or calories! It’s a miracle.
But how do they go about doing it?
In many of these products, the answer is sugar alcohols. Sugar alcohols are manufactured as sugar substitutes that give foods the sweet taste of sugar without spiking your blood sugar levels — adding flavor without the calories.
But what was once hailed as a major win for the sweet tooth is increasingly coming under scrutiny as recent studies of xylitol, a sugar substitute commonly used in processed foods, reveal that the full scope of sugar alcohols may not be so sweet after all.
“Our study shows that elevated blood levels of xylitol contribute to heightened platelet reactivity and are associated with an increased risk of cardiovascular disease, including heart attack and stroke,” said physician-scientist Stanley Hazen, MD, PhD, lead author of the study that sheds light on xylitol’s dark side.
Dr. Hazen explains what xylitol is, the risks it poses, and what to do about it.
What is Xylitol?
Xylitol is a sugar alcohol found most commonly in candies and desserts labeled “keto-friendly,” “diabetes-friendly,” “sugar-free,” or “zero calorie.” Sugar alcohols are compounds that have a chemical structure similar to sugar. Although they taste like sugar, they do not have the same effects on the body as sugar.
Xylitol isn’t just one of those artificial sweetener packets you find on your table at a restaurant. It’s an additive used in food manufacturing plants and is sometimes sold as a sugar substitute in the bread section of your grocery store.
“Food manufacturers use sugar alcohols as a non-nutritive sweetener in sugar-free candies and baked goods. Xylitol tastes like sugar to our tongue but doesn’t affect blood sugar the way glucose (sugar) does,” says Dr. Hazen.
In addition to being found in foods, xylitol is also commonly found in dental products like toothpaste and mouthwash because not only does it taste sweet, but it also helps prevent and reduce the symptoms of tooth decay.
Xylitol is a natural compound produced in our bodies in very small amounts, much lower than the amounts used in food production, and high concentrations of xylitol can pose big problems.
Risks of Xylitol in Food
Sugar alcohols, when consumed in large quantities as a sugar substitute, are known to cause problems for some people — bloating, gas, upset stomach, diarrhea, and weight gain — but Dr. Hazen’s research shows the effects could be far more dangerous.
His team’s research suggests that people who produce high amounts of xylitol in their bodies may be at higher risk of cardiovascular disease.
Additionally, consuming foods and beverages sweetened with xylitol may make platelets in the blood more likely to clot, which can lead to serious heart attacks.
In a study conducted by Dr. Hazen’s team, healthy volunteers were given a drink sweetened with 30 grams of xylitol, about the amount found in a scoop of ketogenic ice cream or a few cookies marketed to people with diabetes.
All volunteers in the study showed a significant tendency for their platelets to clot more easily after consuming xylitol.
“In the presence of xylitol, platelets react more vigorously and are primed to clot,” Dr. Hazen reports. “It’s as if platelets have a kind of taste bud receptor for xylitol that puts them into overdrive. And this is very important, because increased clotting can stop blood flow.”
Is this the result of blood flow being cut off?
Heart attack. Stroke. Other life-threatening cardiovascular diseases.
The research team discovered the risks of xylitol while searching for new pathways linked to heart disease risk. They looked at blood samples from 3,000 people, hoping to identify substances that were elevated in the blood of people who had suffered serious heart attacks. Xylitol was high on the list.
However, just because xylitol is in the blood doesn’t necessarily mean that it will cause a heart attack. Additional research has confirmed that elevated xylitol concentrations increase platelet reactivity and, in non-human model studies, the likelihood of clotting.
“We asked healthy volunteers to drink a xylitol-sweetened beverage and then tested their blood before and after consumption. Xylitol concentrations remained elevated for four to six hours after consumption, which increased platelet responses and clotting risk in all study participants,” explains Dr. Hazen.
Platelet function returned to normal levels by the next day, but risk may remain for people who continue to consume foods containing xylitol.
“It’s not hard to imagine that someone with diabetes would eat products containing xylitol all day, every day,” Dr. Hazen elaborates, “so if they continue to consume xylitol, the risk remains. The people who are most at risk of thrombotic events such as heart attack and stroke – people with diabetes – are the ones who are most likely to consume large amounts of xylitol and unknowingly increase that risk even further.”
The results are similar to what Dr. Hazen and his team found in a study of erythritol, another common sugar alcohol. Taken together, these studies have led some medical experts to reconsider the safety of all sugar alcohols. But more testing needs to be done to know for sure.
What about xylitol in toothpaste?
Importantly, Dr. Hazen points out that using toothpaste or mouthwash that contains xylitol likely doesn’t pose the same risks.
“We know that xylitol in oral care products helps prevent cavities,” he acknowledges, “and since we’re not consuming large amounts of those products, it’s fine for us to use them.”
What foods contain xylitol?
Xylitol is most commonly found in sugar-free candies and other sweets.
Unfortunately, knowing if xylitol is in your food isn’t as easy as reading the nutrition label, since food manufacturers aren’t necessarily required to list the sugar alcohol on their packaging, so xylitol could be hiding without you realizing it.
The U.S. Food and Drug Administration (FDA) guidelines on sugar alcohols state: [is] “About sugar alcohols or sugars when sugar alcohols are present”
In other words, if a package advertises itself as sugar-free, it must list the sugar alcohol content on the label.
But xylitol is just one of the sugar alcohols that food companies use in sugar-free foods. Others include:
Erythritol, sorbitol, maltitol, mannitol, isomalt, lactitol.
Even if a food product is labeled as containing sugar alcohols, it doesn’t necessarily say which sugar alcohols it contains.
Should you avoid xylitol?
That’s the million-dollar question, and it’s a difficult one to answer because you have to weigh the risks of xylitol and other sugar alcohols against the risks of ingesting sugar, neither of which are completely safe, especially for people with diabetes or insulin resistance.
And considering that you don’t necessarily know which foods contain xylitol, it’s even more difficult to know what to avoid.
Dr. Hazen’s advice? “We need to be moderate in what we ingest. I would argue that sugar and honey are actually better alternatives, even for diabetics. But if you are diabetic, you need to watch your blood sugar levels and keep your intake low.”
Even better, satisfy your sweet cravings with natural sugars like fruit, which are less likely to cause a blood sugar spike and provide your body with vitamins and minerals that packaged snacks and desserts can’t provide.
Meanwhile, Dr. Hazen calls for more research and regulation to help both health professionals and patients understand what’s in their food and what risks it may pose.
“This is a population-wide health issue,” Dr. Hazen emphasizes. “We hope that this study and future studies will prompt a re-evaluation of regulatory guidelines regarding artificial sweeteners. We need to study this topic further so that people aren’t inadvertently choosing things they think are healthy when in fact they aren’t.”
