New concerns about diet sodas

They're linked to calorie absorption, high blood pressure, and heart trouble.

For weight-conscious people who love the bite of carbonation and the taste of various soft drinks, the advent of sugar-free sodas 60 years ago seemed a blessing: if there were no calories, you didn't have to worry about weight gain—and the diseases that go along with obesity, like diabetes and heart disease. "But there are growing doubts about whether diet sodas really help people lose weight and avoid diabetes," says Dr. Anthony Komaroff, editor in chief of the Health Letter.