Dr. Jeremy London sees first-hand what heart disease, the world’s biggest killer, can do to a person’s health. As a board-certified cardiovascular surgeon who operates on diseased hearts, he repairs damaged blood vessels and performs bypass surgery for .

“That didn’t happen overnight in most people — it’s an accumulation of a chronic process,” London, who practices in Savannah, Georgia, tells TODAY.com. By adopting certain unhealthy habits, “you’re putting yourself at risk that you’re going to end up on my operating room table,” he cautions others.

London keeps that warning in mind for his own heart as well, putting together a popular list he titled, “Things I avoid as a heart surgeon” . Here are six things the doctor stays away from to keep his heart healthy: This really surprises people, but alcohol-based mouthwash that promises to kill virtually all germs can impact blood pressure, London says. Good bacteria in the mouth help the body produce nitric oxide, which is involved in dilating blood vessels and keeping blood pressure in check, he explains.

But antibacterial mouthwash also kills the beneficial bugs, interrupting that process. Regular use of mouthwash was associated with increased risk of high blood pressure, independent of major risk factors for hypertension, a found. There is “unequivocal evidence” that disrupting the oral microbiome by using antiseptic mouthwash will suppress nitric oxide production and negatively impact blood pressu.