Washington (SmartAboutHealth) - Just one extra hour of sleep at night can greatly lower your risk of heart attacks, stroke, and heart failure.

Researchers from the University of Chicago carried out a study on a total of 500 U.S. adults who were all middle-aged.

Theyw ere studied for a period of 5-years and had their hearts checked at the start and end of the periods.

Overall, all of the adults got an average of 6 hours of sleep each night.

What they found was that an extra hour of sleep lowered their risk of developing coronary artery calcification, which consist of clogged arteries.

With arteries clogged, it makes it more likely that an event such as a heart attack or stroke will occur.

One extra hour of sleep each night reduced the risk of developing the condition by 33%.

The study has been published in the Journal of the American Medical Association.