Not flossing

While the exact reason is unknown, there is a strong link between gum disease and heart disease, Dr. Ostfeld says. If you don't floss, sticky, bacteria-laden plaque builds up over time, which can lead to gum disease. One theory is that these bacteria trigger inflammation in the body.

"Inflammation promotes all aspects of atherosclerosis," Dr. Ostfeld says. Treating gum disease can improve blood vessel function.

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