Gum disease and heart disease -- no link after all?

Gum disease -- it raises the risk of heart disease and stroke, doesn’t it? We’ve long been told there’s a link. But here’s a statement put out Wednesday by the American Heart Assn.:

“Keeping teeth and gums healthy is important for your overall health,” the heart association’s statement begins. “However, an American Heart Association expert committee -- made up of cardiologists, dentists and infectious diseases specialists -- found no conclusive scientific evidence that gum disease, also known as periodontal disease, causes or increases the rates of cardiovascular diseases. Current data don’t indicate whether regular brushing and flossing or treatment of gum disease can cut the incidence of atherosclerosis, the narrowing of the arteries that can cause heart attacks and strokes.”

You can read the whole statement at the AHA website.

Knock me down with a feather. (Next scientists will be telling us that fish oil doesn’t help prevent heart attacks in people with heart disease ... Oh wait, they just did.)

The statement, which comes after a review of 500 journal articles and studies, notes that there have been a lot of population studies that suggest a link between poor oral health and poor heart health, meaning people who have gum disease are also more likely than the Average Joe to have heart disease as well. And vice versa.

But the problem with population studies is that they don’t prove cause and effect, and the same lifestyle and/or physiological factors that contribute to gum disease may also contribute to heart disease. Such as smoking. Or older age. Or diabetes. Two separate conditions can develop at the same time, for the same root reason –- but that doesn’t mean that one caused the other.

And people who don’t look after their gums may also not look after their heart. The gold-standard clinical trials that would properly figure out the relationship -- get a huge group of people, randomly select half of them to brush and floss diligently, let the others develop gum disease, then track the outcomes over years and years -- would be expensive and unwieldy and aren’t likely to ever be done.

The American Dental Assn. on Scientific Affairs and the World Heart Federation both agree with the report’s conclusions.

But floss and brush your teeth anyway. There are other good reasons.