Brushing Your Teeth Can Lower Heart Disease Risk

Overall, 5,008 plaque samples were taken from several teeth, beneath the gum, and analyzed for 11 bacterial strains linked to periodontal disease and seven control bacteria.

Fluid around the gums was sampled to assess levels of Interleukin-1a, a marker of inflammation. Atherosclerosis in both carotid arteries was measured using high-resolution ultrasound.

Over a median follow-up period of three years, the researchers found that improvement in periodontal health—health of the gums—and a reduction in the proportion of specific bacteria linked to periodontal disease correlated to a slower intima-medial thickness (IMT) progression, and worsening periodontal infections paralleled the progression of IMT.

Results were adjusted for potential confounders such as body mass index, cholesterol levels, diabetes, and smoking status.There was a 0.1 mm difference in IMT change over three years among study participants whose periodontal health was deteriorating compared with those whose periodontal health was improving.

Previous research has shown that a .033 mm/year increase in carotid IMT (equivalent to approximately 0.1 mm over three years) is associated with a 2.3-fold increased risk for coronary events.

"When it comes to atherosclerosis, a tenth of a millimeter in the thickness of the carotid artery is a big deal. Based on prior research, it appears to meet the threshold of clinical significance," Tatjana Rundek, MD, PhD, a co-author of the study and professor at the University of Miami whose lab read the carotid ultrasounds, said.

The findings are published online in the Journal of the American Heart Association.