If you’re worried about heart disease, you can easily spend thousands of dollars each year trying to prevent it, paying hand over fist for prescription medicines, shelves of healthy cookbooks, fitnessmachines for your home, and a gym membership.

Or maybe not. A number of recent studies suggest that you may already have a cheap and powerful weapon against heart attacks, strokes, and other heart disease conditions. It costs less than $2 and is sitting on your bathroom counter. It is none other than the humble toothbrush.

“There are a lot of studies that suggest that oral health, and gum disease in particular, are related to serious conditions like heart disease,” says periodontist Sally Cram, DDS, a spokeswoman for the American Dental Association.

So can preventing periodontal disease, a disease of the gums and bone that support the teeth, with brushing and flossing prevent heart disease?

The evidence isn’t clear yet, experts say, but it’s intriguing. According to the American Academy of Periodontology, people with periodontal disease are almost twice as likely to have coronary artery disease (also called heart disease). And one study found that the presence of common problems in the mouth, including gum disease (gingivitis), cavities, and missing teeth, were as good at predicting heart disease as cholesterol levels.

When it comes to the connection between periodontal disease and heart disease, epidemiologist Moise Desvarieux, MD, PhD, is used to dealing with skeptics.

“One of the talks I give is called, ‘Investigating the Links Between Periodontal Infection and Vascular Disease: Are We Nuts?'” says Desvarieux, from Columbia University’s Mailman School of Public Health. “It’s not a connection that people naturally think of.”

Desvarieux was the lead author of a recent study published inCirculation: Journal of the American Heart Association that studied 657 people without known heart disease. He and his co-authors found that people who had higher blood levels of certain disease-causing bacteria in the mouth were more likely to have atherosclerosis in the carotid artery in the neck. Clogging of the carotid arteries can lead to stroke.

Atherosclerosis, also called “hardening of the arteries,” develops when deposits of fats and other substances in your blood begin to stick to the sides of your arteries. These deposits, called plaques, can build up and narrow your arteries, clogging them like a plugged-up drain. If these plaques ever block the blood flow completely, you could have a heart attack or stroke, depending on the location of the blockage.

(Note: Not all plaque is alike. The plaques in your arteries have nothing to do with dental plaque your dental hygienist scrapes off your teeth. Dental plaque is a sticky residue of bacteria, acid, and food particles that can irritate your gums and eat away at tooth enamel.)