People with the Most of This Sugar Substitute in Their Blood Had More Heart Attacks and Strokes

People whose blood carried the highest levels of the sweetener xylitol had substantially more heart attacks, strokes and deaths than people with the lowest levels, according to an analysis of nearly 18,000 people presented at a major cardiology meeting in Munich.

The European Society of Cardiology announced the findings ahead of a congress session on nutrition and heart disease. Over six years of follow-up in the Canadian Longitudinal Study on Aging, the risk of a major adverse cardiovascular event, defined as death, heart attack or stroke, was 57 percent higher in the top quartile of blood xylitol compared with the bottom, after correcting for age, sex, smoking status, lipid levels, diabetes and hypertension.

A second cohort, EPIC-Norfolk in the United Kingdom, followed participants for 30 years and found an 18 percent higher risk in the top quartile. Compared with the middle quartiles, the researchers described a dose-dependent pattern in both groups.

The Word Doing the Heavy Lifting Here Is Associated

This is observational research, and the distinction matters more than the percentage does. The analysis measured xylitol in blood and counted events that followed. It did not assign anyone to consume xylitol, and it cannot establish that the sweetener caused the events.

Professor Dan Atar of the ESC Communication Committee, who was not involved in the analysis, put the limitation plainly in the society's announcement. "As with all observational studies, causalities are difficult to infer," he said, while adding that the work shows further study of the topic is warranted.

There is a second limitation worth naming early. The research measured blood levels, not diet. Xylitol occurs naturally in the body as a byproduct of glucose metabolism, so a high blood level does not automatically mean a person consumed a great deal of it. The researchers reported that the association held independently of body mass index, hypertension, diabetes and lipid levels, which addresses part of that concern without resolving it, and that the pattern was consistent regardless of age and sex.

The findings were also presented at a conference. Conference presentations have not usually completed peer review, and figures can change before full publication.

The Laboratory Work Behind the Signal

The reason cardiologists are paying attention is that this is not a finding without a proposed mechanism.

Presenter Dr. Marco Witkowski of Charité University Hospital in Berlin noted that his group's earlier work showed xylitol can enhance the ability of platelets to form clots, and that high blood levels were linked to cardiovascular events in higher-risk individuals over a three-year period. That earlier research appeared in the European Heart Journal in 2024, and MedicalDaily covered it at the time in a report on xylitol and heart attack and stroke risk.

What is new is scale and duration. The new analysis covers 17,710 people drawn from two general-population cohorts and follows them for six and 30 years.

A plausible mechanism plus a consistent association across independent cohorts is stronger evidence than either alone. It still is not a trial.

Where Xylitol Actually Turns Up in a Kitchen

Xylitol is a sugar alcohol. It appears naturally in some foods in very small amounts, and the ESC notes that it is added to foods, beverages and oral care products at concentrations often more than 1,000 times higher.

It is common in sugar-free chewing gum and mints, some sugar-free candies and baked goods, certain protein and snack bars, some peanut and nut butters, and a great many toothpastes and mouthwashes. Products marketed as keto-friendly, diabetic-friendly or tooth-friendly frequently contain it.

The label is the only reliable way to know. Xylitol appears in ingredient lists by name, and the FDA notes it may also be listed as birch sugar or wood sugar. A product carrying a sugar-free claim is not necessarily sweetened with xylitol rather than another substitute.

One separate point deserves mention because it is established rather than uncertain. The FDA warns that xylitol is dangerous for dogs, because dogs absorb it quickly and can release a surge of insulin that drops blood sugar dangerously within 10 to 60 minutes. Even small amounts of sugar-free gum can cause that reaction. The risk is well documented and is unrelated to the cardiovascular question.

Reasonable Steps and Unreasonable Ones

Nothing here justifies alarm or a wholesale change to how a household eats.

The evidence does not support telling anyone to stop using xylitol, and it certainly does not support returning to added sugar, which carries its own well-established cardiometabolic risks. Regulatory agencies have not changed xylitol's status, and no professional body has revised guidance on sweeteners on the basis of this presentation.

For most people, a reasonable response is simply awareness. Someone consuming xylitol-sweetened products many times a day, every day, is in a different position from someone who chews a piece of gum occasionally. People with diabetes are worth singling out here, not because they face a proven risk but because sugar-free products are marketed to them heavily and daily consumption is the plausible high-exposure pattern.

Anyone with existing cardiovascular disease, prior heart attack or stroke, or a clotting disorder can raise this with a cardiologist at a routine visit. It is a conversation, not an emergency.

No one should stop a prescribed medication or change a diabetes management plan on the basis of a conference abstract. Blood xylitol is not a test available in ordinary clinical practice, and there is no reason to seek it.

The researchers said further studies on the cardiovascular safety of xylitol and other sweeteners are warranted, particularly as the amount used in products continues to rise. The work was supported by the Canada First Research Excellence Fund, the Fonds de recherche du Québec, the Corona Foundation and the Berlin Institute of Health, and Dr. Witkowski reported no conflicts of interest. Full publication and any regulatory response are the next things to watch.

Key Questions Answered

What did the new analysis find? People in the highest quartile of blood xylitol had a 57 percent higher rate of major adverse cardiovascular events over six years in one cohort, and 18 percent higher over 30 years in another.

Does this prove xylitol causes heart attacks? No. This is observational research showing an association. It cannot establish cause, and an ESC commentator noted that causality is difficult to infer from this study design.

How many people were studied? 17,710 participants across two prospective observational cohorts, the Canadian Longitudinal Study on Aging and EPIC-Norfolk in the United Kingdom.

Which foods contain xylitol? Sugar-free gum and mints, some sugar-free candies and baked goods, certain snack bars and nut butters, and many toothpastes and mouthwashes. The ingredient list is a reliable check.

Should people stop consuming xylitol? No health authority has issued such advice, and the evidence does not support it. Returning to added sugar carries its own established risks. People with heavy daily exposure can raise it with a clinician.

Has this been peer reviewed? The analysis was presented at a scientific congress. Conference presentations typically precede full peer-reviewed publication, and figures can change.

Is xylitol dangerous to pets? Yes, and this is well established and separate from the heart question. The FDA warns that xylitol is dangerous for dogs, and sugar-free gum should be kept out of reach.

Originally published on Medical Daily