What does your mouth have to do with your heart?

Heart disease is one of the world's biggest killers, but many people with heart and blood vessel disease have none of the usual risk factors, such as obesity, smoking or high cholesterol.

Gum disease is one of the most common diseases, and several theories suggest a link between mouth infections and heart disease. Certain proteins made by bacteria may start and drive atherosclerosis (hardening of the arteries); among the most studied are heat shock proteins.

Heat shock proteins are made by bacteria, animals and plants when cells are stressed by inflammation, toxins, starvation, or lack of oxygen or water, so some call them stress proteins. They act as "chaperones", stabilising other proteins, helping them fold and carrying them across cell membranes; some bind foreign antigens and present them to the immune system.

Because both the body's cells and bacteria make heat shock proteins, the immune system may not be able to tell them apart and may attack the body's own proteins. This sets off inflammation in the artery walls and starts the build-up of fatty plaques. So when the immune system fights a mouth infection, the similarity between bacterial and human proteins may spark atherosclerosis.

So don't neglect your teeth and gums, and get any infection in them treated.