A common sweetener used in jam and chewing gum has been linked to increased risks of heart attacks and stroke, a new study has shown.

The artificial sweetener xylitol is widely used in foods, drinks and toothpaste to replace sugar – often at 1,000 times the amount found in foods naturally.

In the largest study of its kind into the effects of xylitol on major cardiovascular events, such as a stroke or death, researchers from the Charité University Hospital in Berlin found higher blood levels were associated with greater risks.

Researchers looked at data from 17,710 participants over several years, comparing the 25 per cent with the highest levels of xylitol in their blood to the 25 per cent with the lowest.

Over six years, they found people with the highest levels of xylitol in their blood had a substantially greater risk – 57 per cent – of major cardiovascular events compared to those with the lowest. The difference in risk between the highest and lowest over 30 years was 18 per cent.

The findings were presented on Saturday in Munich at the European Society of Cardiology (ESC) annual congress, the world’s largest heart conference.

In previous studies, we showed that xylitol can enhance the ability of platelets to form clots,” said presenter Dr Marco Witkowski from the Charité University Hospital, Berlin, Germany.

He added: “We also found that high blood levels of xylitol were linked to cardiovascular events in high-risk individuals over a 3-year period.Here we studied if xylitol increases cardiovascular events in a larger sample of the general population over much longer follow-up.”

The research also showed the increased risk linked to xylitol levels was consistent regardless of age and sex, and independent of other risk factors such as body mass index, hypertension and diabetes.

“Artificial sweeteners are consumed by people who think they are healthier than sugar and they are generally regarded as safe by regulatory agencies.”

“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,” Dr Witkowski concluded.