A large observational study has found that people with the highest blood levels of xylitol, a sweetener used in products including chewing gum, toothpaste and low-sugar foods, had a higher risk of heart attack, stroke or death. The findings raise questions about the long-term cardiovascular safety of a widely used ingredient often regarded as a healthier alternative to sugar, though they do not prove that xylitol itself causes these events.

Researchers analysed 17,710 people and found that the quarter with the highest xylitol levels were 57% more likely to experience a major cardiovascular event or die within six years than the quarter with the lowest levels; after 30 years, the difference was 18%. The association appeared dose-dependent and remained after accounting for factors including age, sex, body mass index, high blood pressure, diabetes and lipid levels, but experts stressed that further research is needed because the study was observational.