Human heart
Credit: Yuichiro Chino/Getty Images

A recent study led by researchers at Cleveland Clinic has linked the sugar substitute xylitol to an increased risk of heart attack and stroke. Published in the European Heart Journal, the study found that higher levels of xylitol in the bloodstream are associated with a heightened risk of cardiovascular events, raising concerns about the widespread use of this common sugar alcohol in sugar-free products.

Xylitol, a popular zero-calorie sweetener, is frequently used in sugar-free candies, gums, baked goods, and oral care products like toothpaste. As the popularity of sugar substitutes has surged over the past decade, driven by their promotion as healthy alternatives for managing obesity and diabetes, the potential health risks associated with these substances have come under increasing scrutiny.

The research team, led by Stanley Hazen, MD, PhD, chair of cardiovascular and metabolic sciences at Cleveland Clinic’s Lerner Research Institute, conducted a comprehensive analysis involving over 3,000 patients from the U.S. and Europe.

Their findings revealed that patients with the highest levels of circulating xylitol had a significantly increased three-year risk of experiencing a cardiovascular event, such as a heart attack or stroke. Specifically, a third of these patients were more likely to suffer from blood clot-related events.

To validate these findings, the team conducted preclinical testing, which demonstrated that xylitol causes platelets to clot more readily, increasing the risk of thrombosis. Further, they monitored platelet activity in individuals who consumed a xylitol-sweetened drink compared to a glucose-sweetened drink. The results showed a significant increase in all measures of clotting ability immediately following xylitol ingestion, whereas glucose did not produce the same effect.

“This study again shows the immediate need for investigating sugar alcohols and artificial sweeteners, especially as they continue to be recommended in combating conditions like obesity or diabetes,” said Hazen. He emphasized that while this does not mean people should discard products like toothpaste that contain xylitol, awareness of the potential risks associated with high levels of consumption is crucial.

This research builds on previous findings from the same team, which linked erythritol, another sugar alcohol, to increased cardiovascular risk. Although xylitol is less prevalent than erythritol in the U.S. keto or sugar-free products, it is commonly used in other countries, underscoring the global relevance of these findings.

The study’s authors call for further research to assess the long-term cardiovascular safety of xylitol. They caution that clinical observation studies like this one demonstrate associations rather than causation, highlighting the need for more in-depth investigations. They also recommend that individuals consult with healthcare professionals or certified dietitians to make informed decisions about their dietary choices.

Hazen’s research is part of an ongoing effort to identify factors contributing to residual cardiovascular risk. His team tracks patients over time to find chemical signatures in the blood that can predict future heart and metabolic diseases. His pioneering work has led to significant discoveries in atherosclerosis and inflammatory disease research, including the crucial link between gut microbial pathways and cardiovascular and metabolic diseases.

Also of Interest