Toothless heart disease patients are nearly twice as likely to die as those who have all their teeth, a new study suggests.

Gum disease is the most common cause of tooth loss, and gum disease-related inflammation is believed to play a role in the narrowing of arteries, the researchers said.

"While we can't yet advise patients to look after their teeth to lower their cardiovascular risk, the positive effects of brushing and flossing are well established. The potential for additional positive effects on cardiovascular health would be a bonus," said study lead author Dr. Ola Vedin, a cardiologist at Uppsala University Hospital and Uppsala Clinical Research Center in Sweden.

The study included more than 15,000 heart disease patients in 39 countries. They were assessed for tooth loss and followed for an average of 3.7 years.

The study only found a link, not a cause-and-effect relationship, between dental health and heart health. It was published Dec. 16 in the European Journal of Preventive Cardiology.