Rob Stein

Scientists have discovered what may be an important new risk factor for heart disease. And here's the surprising twist: The troublesome substance seems to be a waste product left behind by bacteria in our guts as they help us digest lecithin — a substance plentiful in red meat, eggs, liver and certain other foods.

Doctors say the research further illustrates the complicated relationship we have with the microbes living inside us, and could lead to new ways to prevent heart attacks and strokes.

Scientists reported Wednesday that they had developed a way to measure how much pain people are experiencing by scanning their brains.

The researchers hope the technique will help doctors treat pain better, but the work is also raising concerns about whether the technique might interfere with doctors simply listening to their patients.

Now, when someone is in pain, a doctor has no way to judge its severity except to ask questions, a method that often is inadequate.

Scientists say they have found a way to get a glimpse of people's dreams.

"Our results show that we can predict what a person's seeing during dreams," says Yukiyasu Kamitani, a researcher at the ATR Computational Neuroscience Laboratories in Kyoto, Japan.

Philosophers, poets and psychologists have long shared a fascination with dreams. But Jack Gallant, a neuroscientist at the University of California, Berkeley says solving the mystery of our dreams is one tough problem.

More than 1 million people are dying prematurely every year from air pollution in China, according to a new analysis.

"This is the highest toll in the world and it really reflects the very high levels of air pollution that exist in China today," says Robert O'Keefe of the Health Effects Institute in Boston, who presented the findings in Beijing this week.

A controversial government proposal to test the anthrax vaccine in children would be unethical without first conducting much more research, a presidential commission concluded Tuesday.

"The federal government would have to take multiple steps before anthrax vaccine trials with children could be ethically considered," Amy Gutmann, who chairs the Presidential Commission for the Study of Bioethical Issues, tells Shots. "It would not be ethical to do it today."