BAKERSFIELD, Calif. -- Millions of Americans take aspirin or other blood-thinning drugs to cut their chances of dangerous clots -- blood clots in the arteries can cause heart attacks, while those in the brain trigger strokes.

Anti-clotting medications carry a small risk for bleeding in the gastrointestinal tract -- the esophagus, stomach or intestines.

But new research has suggested that anti-clotting drugs can also raise the odds of tiny bleeds in the brain.

Doctors in the Netherlands performed MRI brain scans on more than 1,000 healthy adults over the age of 60. They found that those taking aspirin or a similar drug had a 71 percent greater chance of microscopic brain bleeds.

The participants did not appear to have any symptoms as a result of their brain bleeds -- so it's possible they are no reason for concern, especially when weighed against aspirin's proven heart benefits.

But researchers said that future studies should follow up with patients to see if the microscopic brain bleeds raise the chances of more serious bleeding down the road.