By High levels of xylitol in the blood were associated with a higher risk of heart attack, stroke and cardiovascular death, according to new research presented at the European Society of Cardiology Congress 2026. The findings do not prove that the sugar-free sweetener causes heart problems, but add to growing questions about the long-term cardiovascular safety of sugar alcohols.
The analysis looked at 17,710 adults from two long-running prospective studies and found that people with blood xylitol in the highest quartile had a 57% higher risk of major adverse cardiovascular events over six years compared with those in the lowest quartile in one cohort, and an 18% higher risk over 30 years in the second cohort. Researchers say further controlled studies are needed.
What the new study found
The research, led by Dr Marco Witkowski from Charité – Universitätsmedizin Berlin, will be presented at ESC Congress 2026 in Munich during the Hungry heart: nutrient deficiencies and cardiovascular disease session.
The team analyzed data from two prospective observational cohorts: the Canadian Longitudinal Study on Aging (CLSA) and the European Prospective Investigation into Cancer (EPIC)-Norfolk. Together the cohorts included 17,710 participants.
Rather than asking people how much gum they chew, researchers measured xylitol levels in fasting blood samples using mass spectrometry and divided participants into four groups, from lowest to highest levels.
Major adverse cardiovascular events, or MACE, were defined as death, myocardial infarction or stroke.
Over a six-year follow-up in the CLSA cohort, people in the highest quartile of xylitol had a 57% higher risk of MACE than those in the lowest quartile after adjusting for established risk factors including age, sex, smoking, lipid levels, diabetes and hypertension.
Over a 30-year follow-up in EPIC-Norfolk, the same comparison showed an 18% higher risk in the highest versus lowest quartile.
When results from the middle quartiles were included, both cohorts showed a dose-dependent pattern: as blood xylitol levels rose, so did the rate of cardiovascular events. The association appeared consistent across age and sex, and was independent of body mass index, hypertension, diabetes and lipid levels, according to the ESC press release.
The study builds on earlier work by the same group. In 2024, Witkowski and colleagues reported in the European Heart Journal study on xylitol and cardiovascular risk that circulating xylitol was associated with a 3-year risk of MACE in high-risk patients undergoing cardiac evaluation, with a hazard ratio of 1.57 for the third versus first tertile. That paper also included laboratory work.
What does the 57% figure actually mean?
The 57% and 18% figures are relative differences between groups, not absolute risks for an individual.
In the CLSA analysis, researchers compared the group with the highest measured blood xylitol to the group with the lowest. The 57% higher risk means that, over six years, cardiovascular events occurred more often in the high-xylitol group than in the low-xylitol group, after accounting for other risk factors.
It does not mean that 57 out of 100 people will have a heart attack, nor that eating one piece of sugar-free gum raises personal risk by 57%. It also does not tell us how much xylitol those participants consumed, because blood levels reflect a mix of dietary intake, absorption, metabolism and naturally produced xylitol.
Xylitol is produced endogenously in the body as a by-product of glucose metabolism, but at levels more than 1,000-fold lower than those typically seen after consuming xylitol-sweetened products, according to ESC. Measuring blood levels therefore cannot directly translate into a number of chewing gums or mints.
Observational studies like this can identify associations but cannot establish that xylitol caused the events. As ESC commentator Professor Dan Atar noted, causal inference is difficult from observational data and further studies are mandated.
What is xylitol?
Xylitol is a sugar alcohol, also called a polyol. It occurs naturally in very small amounts in some fruits and vegetables, such as berries and plums, and is produced in small amounts by the human body. Commercial xylitol is usually made from birch bark or corn cobs.
Manufacturers use it because it provides sweetness with about 40% fewer calories than sugar, does not cause a sharp rise in blood glucose, and has a cooling taste. It is distinct from high-intensity artificial sweeteners such as aspartame, sucralose and saccharin, which are chemically different and many times sweeter than sugar.
Xylitol is popular in sugar-free chewing gum because it is not fermented by oral bacteria that cause tooth decay. The NHS advice on looking after teeth notes that sugar-free gum can help stimulate saliva after meals, and many dental products contain xylitol for that reason.
Where xylitol can be found
Xylitol may be listed in the ingredients of a range of products, but not all sugar-free products contain it. Examples where it is commonly used include:
- sugar-free chewing gum and mints
- sugar-free sweets and confectionery
- toothpaste and mouthwash
- some jams, peanut butters and baked goods marketed as reduced-sugar or keto-friendly
- certain drinks and flavourings
- some medicines and dietary supplements
The amount varies widely between brands. Checking the ingredient list is the most reliable way to know whether a product contains xylitol. In the UK and EU, xylitol is authorised as a food additive (E967) and is generally regarded as safe by food safety authorities when used within approved limits, although labelling does not currently require a warning about cardiovascular risk.
Why might xylitol be linked to heart problems?
Previous laboratory work has proposed a possible mechanism involving platelets, the small blood cells that help form clots to stop bleeding.
Platelets cluster at the site of injury to form a plug. If they become overly reactive and clot inside an artery that supplies the heart or brain, this can contribute to a heart attack or ischaemic stroke.
In the 2024 European Heart Journal paper and subsequent work summarised by the NIH research summary on xylitol and cardiovascular health, researchers showed that xylitol at levels found in fasting plasma enhanced several measures of platelet reactivity in human whole blood, platelet-rich plasma and isolated platelets, and increased thrombus formation in animal models. In a small interventional study in 10 healthy volunteers, drinking a xylitol-sweetened drink markedly raised plasma xylitol and enhanced platelet responsiveness.
Similar findings had previously been reported for erythritol, another sugar alcohol, which prompted researchers to look at xylitol more closely. Both substances are sugar alcohols but are metabolised differently, so evidence about one cannot automatically be applied to the other.
It is important to distinguish laboratory evidence, which shows what can happen to cells or animals under controlled conditions, from human outcome evidence, which shows whether events actually occur more often in people. The new CLSA and EPIC-Norfolk data provide human observational evidence, but do not prove that enhancing platelet reactivity through xylitol intake causes heart attacks in everyday life.
Does chewing gum increase your risk?
The study was not a trial of chewing gum, and it did not compare gum chewers with non-chewers. It measured xylitol circulating in blood.
Blood levels can be influenced by many factors, including recent consumption of xylitol-sweetened foods, how quickly the body clears it, kidney function and endogenous production. Someone with high blood levels may have consumed more xylitol, but high levels could also reflect metabolic differences or underlying health conditions that themselves affect cardiovascular risk.
That is why experts caution against interpreting the headline as proof that chewing gum causes heart attacks. A person who occasionally chews sugar-free gum is not automatically in the highest quartile of blood xylitol for six years, and even if they were, association does not equal causation.
What are the limitations of the research?
Like all observational research, this study has limitations that must be considered:
- Association versus causation: The design can show that high xylitol levels and cardiovascular events tend to occur together, but cannot prove that xylitol caused the events.
- Potential confounding: People who use more sugar substitutes may differ in other ways, such as higher baseline weight, diabetes risk or attempts to reduce sugar after a health scare. Although the analysis adjusted for major risk factors, residual confounding is still possible.
- What blood levels mean: Fasting xylitol reflects both intake and metabolism. The study cannot determine how much xylitol came from food, oral care products or endogenous production, nor can it establish a safe intake threshold.
- General population versus high-risk: The cohorts include middle-aged and older adults from Canada and the UK, but findings may not apply equally to younger, healthy people or to people with different dietary patterns.
- Need for intervention studies: Randomized controlled trials that assign people to different amounts of xylitol and measure platelet function and clinical outcomes are needed to test safety directly.
Commenting on the findings at ESC, Professor Atar said artificial sweeteners have been widely embraced and safety ratings had been good, but that the observational data suggest long-term effects that warrant further investigation.
Putting xylitol in context with other sweeteners
Xylitol is one of several low-calorie sweeteners under scrutiny. In 2023, research on erythritol also linked high blood levels to increased cardiovascular risk and platelet reactivity, attracting considerable attention. Artificial sweeteners such as sucralose, aspartame and saccharin have also been examined for links to cardiometabolic outcomes, with mixed results.
It would be misleading to treat all sweeteners as identical. Sugar alcohols like xylitol, erythritol and sorbitol share some chemical features but are absorbed and metabolised differently. High-intensity sweeteners are not sugar alcohols and work through different pathways. The British Heart Foundation information on sugar substitutes notes that overall diet quality matters more than any single ingredient and that evidence on long-term effects is still evolving.
Should people avoid xylitol?
No regulatory authority has advised consumers to stop using xylitol based on these findings. The ESC presentation is an observational analysis, not a safety warning or recall.
Researchers involved say the results highlight how little is known about long-term cardiovascular safety as xylitol use increases in foods and oral care products, and that further studies are warranted, particularly as amounts added to products continue to rise.
For most people, occasional use of sugar-free gum or mints containing xylitol is unlikely to be a major driver of cardiovascular risk compared with established risk factors. People with concerns about sweetener intake or with existing heart disease who use large amounts of sugar-free products may wish to discuss their diet with a GP, dietitian or pharmacist.
Reading ingredient lists, avoiding excessive intake of any one sweetener, and focusing on an overall balanced diet remains sensible. Importantly, xylitol is highly toxic to dogs even in small amounts, so products containing it should be kept away from pets.
What matters most for heart health?
Established ways to reduce risk of heart attack and stroke are supported by much stronger evidence than any single sweetener study. According to NHS guidance on cardiovascular disease and British Heart Foundation advice, key measures include:
- controlling blood pressure and cholesterol and following prescribed treatment
- not smoking and avoiding exposure to second-hand smoke
- being physically active and maintaining a healthy weight
- eating a diet rich in fruit, vegetables, whole grains, oily fish and unsaturated fats while limiting salt, saturated fat and excess sugar
- managing diabetes effectively
- limiting excessive alcohol intake
- seeking prompt medical attention for symptoms such as chest pain, breathlessness or sudden neurological changes
If you have a history of heart attack, stroke or other cardiovascular condition, continue to follow your healthcare team’s advice and do not make major dietary changes based on a single observational study. If new official guidance on xylitol is issued by UK food safety or health authorities, it will be published through the Food Standards Agency and NHS channels.
Dr. Samuel Kemp is a Consultant Physician at the Royal Brompton Hospital with specialist expertise in respiratory medicine, including lung cancer, COPD, and advanced interventional bronchoscopy.