A sugar substitute sitting in millions of American kitchen cabinets, gym bags and toothpaste tubes is facing its most serious safety question yet. Researchers presenting at the European Society of Cardiology congress in Munich reported that adults with the highest blood levels of xylitol were 57 percent more likely to have a heart attack, a stroke or to die over six years than adults with the lowest levels.
The analysis covered 17,710 adults across two long-running population studies. It is the largest look so far at xylitol in the general population rather than in people already under cardiac care, and it lands at a moment when sugar-free products are marketed heavily to shoppers trying to cut added sugar.
For a household, the practical question is narrower than the headline number suggests. Nobody is being told to throw out toothpaste. But anyone using xylitol-sweetened gum, mints, protein bars, baked goods or bulk granulated sweetener several times a day may reasonably want to talk with a clinician about it, particularly if they already carry heart risk factors.
Inside the Two Cohorts Behind the 57 Percent Figure
The research team drew on the Canadian Longitudinal Study on Aging and the European Prospective Investigation into Cancer Norfolk study, two prospective observational projects that banked blood samples and then tracked what happened to participants.
In the Canadian cohort, followed for six years, people in the top quartile of circulating xylitol had a 57 percent higher rate of major adverse cardiovascular events, defined as death, heart attack or stroke, compared with the bottom quartile. That figure held after correction for known cardiovascular risk factors including age, sex, smoking status, lipid levels, diabetes and high blood pressure.
In the Norfolk cohort, followed for 30 years, the same comparison produced an 18 percent higher risk. Taken with the middle quartiles, the researchers described a dose-dependent pattern, with event rates climbing as blood levels climbed. The association also held independent of body mass index, a point the team highlighted because heavier people tend to reach for low-calorie products more often.
The gap between the two cohorts is itself worth noting. Presenter Marco Witkowski of Charité University Hospital in Berlin attributed the difference in effect size to the two populations sitting on different continents with different lifestyle exposures. The work was presented during a conference session and has not yet appeared in a peer-reviewed journal. Funding came from the Canada First Research Excellence Fund, the Fonds de recherche du Québec, the Corona Foundation, and the Berlin Institute of Health, and Witkowski reported no conflicts of interest.
Everyday Products That Contain Xylitol
Xylitol occurs naturally in the human body as a byproduct of glucose metabolism and appears in trace amounts in some foods. The version people consume is different in scale. Manufacturers add it to foods, drinks, and oral care products at concentrations that can run more than a thousand times higher than natural levels.
Shoppers most often encounter it in sugar-free chewing gum, breath mints, toothpaste, mouthwash, keto and diabetic friendly baked goods, and granulated sweetener sold for home baking. Dentists have long recommended it because it does not feed the bacteria that drive tooth decay, which is why it turns up so often in products aimed at children and at adults managing cavities.
That dental history is part of why the new data matters. Xylitol has been treated as one of the safer sugar alternatives. Witkowski said the long term findings in the general population highlight "how little we know about the cardiovascular safety of xylitol."
Dan Atar, a member of the society's communication committee, commented separately that regulators had granted these sweeteners good safety ratings and that, as with all observational work, "causalities are difficult to infer." He added that the topic now warrants further study.
Evidence Check: Association, Not Proof of Cause
This is an observational study, and the distinction matters for how readers should act on it. The design can show that high xylitol levels travel alongside more cardiac events. It cannot show that xylitol caused those events.
Blood levels also reflect more than diet, and this is the study's most important limitation. Witkowski has said that in overnight fasting samples, the kind used here, xylitol levels likely represent the body's own production rather than what a person ate, because the kidneys clear dietary xylitol quickly. The researchers did not measure how much xylitol participants consumed. That means the analysis establishes a link between circulating levels and cardiac events, not between eating xylitol and having a heart attack.
The strongest supporting evidence is mechanistic. A 2024 paper in the European Heart Journal reported that xylitol increased platelet reactivity in laboratory and animal work and in ten healthy volunteers who drank a xylitol-sweetened beverage, and linked higher levels to cardiac events over three years in patients undergoing cardiac evaluation. A commentary in the same journal noted that observational clinical data can show association only, not causation.
The European Food Information Council cautioned that the results remain unpublished, observational and expressed as relative rather than absolute risk, meaning an individual cannot calculate a personal risk figure from them. No regulator has changed its position on xylitol, and no medical guideline has been revised.
Steps Shoppers and Patients Can Take Now
Nobody needs to empty a medicine cabinet over a conference presentation. What is reasonable is label awareness. Xylitol is listed by name in ingredient panels, and people who use several sugar-free products daily may be consuming more than they realize. Witkowski's own advice was that people with additional cardiovascular risk factors avoid heavily sweetened processed foods containing large amounts of sugar alcohols.
Anyone with existing heart disease, prior stroke, diabetes, or a clotting disorder can raise the question at their next appointment rather than making unilateral changes. That is especially true for people taking blood thinners, since the proposed mechanism involves platelet activity. Do not stop or start any prescribed medication without speaking to a clinician.
Households with dogs should keep a separate concern in mind. Federal regulators warn that xylitol is dangerous to dogs even in small amounts, and sugar-free gum left in a bag or on a counter is a common poisoning route.
The next milestone is publication. Until the full analysis clears peer review, the honest summary is that a large, well-adjusted observational dataset has raised a consistent signal, and that the signal is not yet proof. The presenter's own framing was a call for more research and for regulators to weigh the existing evidence, not a call to avoid the product outright.
Key Questions Answered
What did the new study actually find? Among 17,710 adults, those with the highest blood xylitol levels had a 57 percent higher six-year risk of heart attack, stroke, or death in one cohort and an 18 percent higher risk over 30 years in another.
Does this prove xylitol causes heart attacks? No. The study is observational. It shows an association and a dose-dependent pattern, not a causal link.
Did the researchers measure how much xylitol people ate? No. They measured blood concentrations only, and fasting levels may largely reflect the body's own production rather than diet.
Which products contain xylitol? Sugar-free gum, mints, toothpaste, mouthwash, low-carbohydrate baked goods, and granulated sweetener sold for home baking.
Has any regulator changed its guidance? No. Xylitol remains an approved sweetener, and no medical guideline has been updated in response to these findings.
Who should be most attentive to this? People with existing cardiovascular disease, diabetes or clotting disorders, and heavy daily users of multiple xylitol-containing products.
Should anyone stop using xylitol toothpaste? There is no evidence supporting that step. Oral care products are used briefly and largely spat out rather than swallowed.
