Researchers found that older adults who drank diet soda daily were 44 percent more likely to suffer a heart attack. But they say their findings did not prove sugar-free drinks alone were to blame.
Some diet soda drinkers tend to be heavier and more often have heart risk factors such as high blood pressure, diabetes and unhealthy cholesterol levels.
Research in rats also suggests artificial sweeteners can boost food intake and weight, but it is not known if the same is true in people.
This study appears in the Journal of General Internal Medicine.