Sanjay Gupta, CNN Health

After years of recommending regular aspirin to prevent heart attack and stroke, scientists now see little benefit for most healthy people and say it may contribute to a risk of bleeding in the stomach or brain, which goes up as one gets older. The task force now says people older than 60 should not start taking a daily aspirin for primary prevention of heart problems, in most cases. For those between 40 and 59 years old, the task force leaves it up to them and their doctors to decide whether they should take a daily aspirin in specific circumstances. Doctors say a healthy 40-year-old with no major risk factors could do more harm than good with daily aspirin, as the risk of bleeding would exceed the benefits. But if someone has had a heart attack, a stroke, or other heart or circulation problems and their doctor has put them on daily aspirin, they should not necessarily stop. Instead, they should talk with their doctors about what the new recommendations mean for them.