A common sweetener used in products such as chewing gum, toothpaste, jam, yoghurts and ice-cream has been linked to an increased risk of strokes, heart attacks and death.
Xylitol is a sugar alcohol present in some natural foods in very low amounts. It is also added – often in amounts 1,000 times higher – to artificially sweeten foods, beverages and oral care products.
Despite its growing use, the long-term health impacts of xylitol have never been widely studied.
In the largest study of its kind, researchers found high blood levels of xylitol were associated with an increased risk of major adverse cardiovascular events. The findings were presented in Munich at the European Society of Cardiology (ESC) annual congress, the world’s largest heart conference.
Researchers looked at 17,710 people and compared the 25% with the highest levels of xylitol in their blood against the 25% with the lowest.
Those who had the highest amount were 57% more likely to die or suffer a heart attack or stroke, than those with the least, within six years. Even after 30 years, they were still 18% more likely to have suffered one of these cardiac events.
Taken with data from the middle quartiles, the results from both cohorts suggested a dose-dependent relationship: the higher the xylitol blood levels, the higher the cardiovascular event rate.
Furthermore, the researchers showed that there was consistent increase in cardiovascular events with xylitol irrespective of baseline characteristics, such as age and sex.
The researchers also highlighted that 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.
The study’s author, Dr Marco Witkowski, from the Charité university hospital in Berlin, said the results built on research that had raised concerns about xylitol.
“In previous studies, we showed that xylitol can enhance the ability of platelets to form clots,” he said. Witkowski and his colleagues also found that high blood levels of xylitol were linked to adverse heart events in high-risk people over a three-year period.
“Artificial sweeteners are consumed by people who think they are healthier than sugar and they are generally regarded as safe by regulatory agencies,” he said.
“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.”
Prof Dan Atar, an expert member of the ESC communication committee, who was not involved with the research, said: “Artificial sweeteners are widely embraced by modern society, and the safety ratings had been good and granted by regulatory authorities.
“In this observational work, however, it appears that xylitol has a negative long-term effect on cardiovascular events in the general population. As with all observational studies, causalities are difficult to infer, but this work shows that further studies are mandated into this societally important topic.”
Dell Stanford, a senior dietitian at the British Heart Foundation, a charity, said risks to heart health built up over time, and it was vital to ensure that what was being added to foods did not contribute.
Stanford said: “Artificial sweeteners such as xylitol are found in many foods and drinks, and people may assume they are the healthier choice, so consume more than they realise. This study adds to growing evidence that artificial sweeteners could have an impact on our health.
“It is important to note that this was an observational study, meaning it can only show an association between higher xylitol levels and cardiovascular events, rather than proving that xylitol directly caused them, and further research is needed. But it is not a green light to have more sugar instead, as we still need to reduce our free sugar intake.
“This study is a reminder that we all need to reduce our intake of processed foods and drinks that are often high in sugar, salt or sweeteners, and focus on a balanced diet to help protect our hearts.”
