Want healthy knees? Then you better floss your teeth. Yes, you read that right. Scientists have found traces of gum bacteria in the knees of people with rheumatoid arthritis and osteoarthritis. The study, published in the Journal of Clinical Rheumatology, adds more evidence of the link between poor oral health and poor health in general.
Researchers from Case Western Reserve University in Cleveland essentially traced the passage of bacteria in the mouth to the fluid surrounded the kneecap, called synovial fluid. By analyzing the DNA of the bacteria, the researchers could determine that gum bacteria entered into the bloodstream and settled in the synovial fluid, which was in a weakened state because of arthritis. In healthy people, the synovial fluid is essentially sterile. Bacteria can make the diseased area much, much worse.
Although it is not conclusive that the gum bacteria caused or worsened the arthritis in the patients it studied, the finding provides a new wrinkle in the still controversial theory of gum disease's role in a host of ailments.
Knee and mouth disease?
Advanced gum disease, or periodontitis, has long been associated with heart disease. One example of this link is the accumulation of plaque in the arteries, called atherosclerosis, which may be exacerbated by the same bacteria causing plaque on the teeth. Another example is an inflamed heart valve, irritated by gum bacteria. That's the theory, anyway.
People with periodontitis are twice as likely to have cardiovascular disease. Researchers in this study have also said his group has unpublished data showing how periodontitis is more of a risk factor for heart attacks than LDL "bad" cholesterol levels or C-reactive protein levels, a measure of inflammation.
And now his group has data tying gum disease to arthritis. The bacteria found in the mouth and in the synovial fluid were genetically nearly identical, providing smoking-gun evidence of bacteria relocating. It is well known that advanced periodontitis can lead to harmful bacteria entering the bloodstream. Once it gets in, it can go anywhere. The target is often a site of existing inflammation, such as the arteries or, in this case, the knee.
It wouldn't be such a bad idea to start brushing and flossing!