Study Links High Xylitol Levels to Increased Risk of Heart Attack, Stroke and Death

People with the highest blood concentrations of xylitol were more likely to experience major cardiovascular events over long-term follow-up, according to an observational study involving more than 17,000 adults, though researchers cautioned that the findings do not prove the popular sugar substitute causes heart disease.

By yourNEWS Media Newsroom

A widely used sugar substitute found in chewing gum, oral-care products, beverages and packaged foods is drawing new scrutiny after researchers found an association between higher blood levels of xylitol and an increased likelihood of serious cardiovascular events.

The observational study, presented at a European Society of Cardiology conference in late August, examined whether circulating xylitol levels were associated with heart attack, stroke or death.

Researchers analyzed information from 17,710 participants enrolled in two large, long-running population studies: the European Prospective Investigation into Cancer-Norfolk study, known as EPIC-Norfolk, and the Canadian Longitudinal Study on Aging, or CLSA.

The strongest association appeared in the Canadian cohort.

Participants in the CLSA with the highest measured xylitol levels had a 57% greater risk of experiencing a major cardiovascular event during approximately six years of follow-up compared with participants whose levels were lowest, according to an Aug. 26 release from the European Society of Cardiology.

Researchers found a smaller but still measurable association in EPIC-Norfolk.

People in that study with the highest xylitol concentrations had an 18% greater risk of major cardiovascular events compared with those in the lowest group.

The relationship persisted after researchers adjusted for several established cardiovascular risk factors.

According to the cardiology society, the association was “independent of underlying factors such as body mass index, hypertension, diabetes and lipid levels, which might predispose people to low-calorie products.”

That adjustment is important because people with obesity, diabetes or other metabolic conditions may be more likely to consume products made with sugar substitutes, creating the possibility that their underlying health conditions rather than xylitol itself could explain elevated cardiovascular risk.

Researchers nevertheless emphasized that the study cannot establish cause and effect.

Because the analysis was observational, it can show that higher xylitol concentrations occurred alongside greater cardiovascular risk but cannot determine whether xylitol itself caused the additional heart attacks, strokes or deaths.

Further research will be needed to determine whether the association represents a direct biological effect, reflects other dietary or metabolic factors, or results from a combination of influences.

Dr. Marco Witkowski of Charité University Hospital in Berlin, who participated in the study, said the findings raise questions about a sweetener that many consumers use because they consider it healthier than conventional sugar.

“Artificial sweeteners are consumed by people who think they are healthier than sugar and they are generally regarded as safe by regulatory agencies,” Witkowski said in an Aug. 26 statement.

He said widespread use makes additional investigation particularly important.

“Our long-term findings in the general population highlight how little we know about the cardiovascular safety of xylitol and indicate that further studies are warranted, especially as the amount of xylitol in products continues to increase,” Witkowski added.

Xylitol is a sugar alcohol that occurs naturally in small amounts in several fruits and vegetables as well as in certain trees.

Commercial xylitol is also sold as a white crystalline powder and has approximately the sweetness of conventional table sugar, according to Harvard Medical School.

Its sweetness and reduced-sugar profile have made it a common ingredient in products marketed to consumers seeking alternatives to ordinary sugar.

Xylitol is particularly prevalent in chewing gums and oral-care products, but it can also appear in drinks, foods and other processed products.

The cardiovascular findings add to previously recognized concerns involving the sweetener.

Research published through the National Institutes of Health has identified gastrointestinal effects including diarrhea, bloating and gas, particularly when xylitol is consumed in larger quantities.

Xylitol also poses a serious and well-established danger to dogs.

Dogs metabolize the substance differently from humans, and ingestion can cause an abrupt, potentially life-threatening decline in blood glucose. Exposure can also result in liver failure or death.

The Food and Drug Administration advises immediate action if a dog is suspected of consuming a xylitol-containing product.

“If you think your dog may have eaten a product containing xylitol, call your vet, emergency clinic, or animal poison control center right away,” the FDA states.

Consumers should also not assume that every product labeled “sugar free” or advertising zero grams of sugar contains xylitol.

Manufacturers use numerous alternative sweeteners, and their ingredients vary considerably from product to product.

Other commonly used sugar substitutes include stevia, erythritol, sorbitol, maltitol, sucralose and aspartame, according to Johns Hopkins University.

Some alternatives originate from naturally occurring substances, while others — including aspartame, saccharin and sucralose — are artificial sweeteners.

The new research focuses specifically on xylitol and does not establish that the same cardiovascular association applies to other sugar substitutes.

It also does not establish that consuming a particular xylitol-containing food will cause a heart attack or stroke.

Instead, the results identify a long-term statistical relationship between higher blood concentrations of the compound and cardiovascular outcomes in two large populations.

The size of that association differed considerably between the two cohorts, ranging from an 18% higher risk in EPIC-Norfolk to a 57% higher risk in the Canadian study among participants with the greatest xylitol concentrations.

That difference, along with the observational design, is among the reasons researchers are calling for additional investigation before drawing firm conclusions about cardiovascular safety.

For consumers, the findings add another question to the ongoing debate over whether replacing conventional sugar with alternative sweeteners necessarily produces better long-term health outcomes.

Xylitol remains widely used and is generally regarded as safe by regulatory agencies, but researchers say its increasing presence in the food supply makes understanding its possible cardiovascular effects more important.

The study therefore stops short of recommending that consumers abandon xylitol.

It instead provides evidence that people with higher circulating levels of the sweetener experienced more cardiovascular events during follow-up — a finding researchers say warrants further studies capable of determining whether xylitol itself contributes to that increased risk.