Heart disease
Population studies have shown that people with gum disease, caused by an accumulation of bacteria in the gums and supporting structures around the teeth, have two or three times the risk of having serious cardiovascular problems such as a heart attack or stroke.
Scientists are just beginning to understand why. One example is a bacteria called porphyromonas gingivalis that releases inflammatory toxins into the bloodstream, which can actually drive stiffening of the arteries or atherosclerosis. These inflammatory processes may even be capable of damaging the heart itself.
“It’s not just the teeth, but the whole system,” says Dr Neesha Patel, a periodontist at the London-based Pure Periodontics clinic. “The mouth is kind of a gateway to the whole body.”
Woodhouse says that people who already have pre-existing cardiac issues, or have previously undergone open-heart surgery, are at a greater risk of incurring damage from gum bacteria if they have poor mouth hygiene. “There is some evidence that if bacteria themselves get into the bloodstream, they can attach to repaired heart valves [and cause inflammation known as endocarditis] and things like that,” he says.
Pneumonia
Within minutes of brushing your teeth, sticky films of bacteria known as dental plaque begin to re-form on your teeth. If this is not cleared within 24 hours, it will begin to harden, which is why it is so important to brush your teeth at least twice per day.
Research has shown that lingering plaque is capable of triggering or worsening the progression of pneumonia, because bacteria can swiftly relocate from the teeth into the respiratory tract. From here, they can move down into the lungs.
“In particular, patients who are already susceptible are more at risk of acute infection,” says Patel. “So immunocompromised patients with severe asthma; patients who are waiting for lung transplants. We have to be really careful about getting on top of any existing gum disease.”
Diabetes
This may seem like an odd link at first. How can poor mouth hygiene be connected to a disease that is driven by a malfunctioning pancreas? However, studies have found a bidirectional relationship between diabetes and gum disease.
Poor blood sugar control can stimulate an overgrowth of harmful bacteria in the mouth, while chronic infections from untreated periodontal problems can induce surges of inflammation in the bloodstream, causing rising blood sugar levels and making the condition harder to manage.
“If the bacteria in your mouth hang around for any length of time, they start producing this stuff called endotoxins,” says Woodhouse. “The body reacts to them and floods the area with inflammatory products, and all those nasty chemicals and toxins floating in your bloodstream go on to mess up lots and lots of bodily systems. Diabetes and periodontal disease: it’s a bit of a chicken and egg scenario. They both exacerbate each other.”
Dementia
Could regular flossing be the key to preserving your mental faculties in later life? The link between oral bacteria and the brain is one of the most compelling new frontiers in dementia research.
One study of 28,000 patients in Taiwan found that those with chronic gum disease for more than a decade were 1.7 times more likely to be at risk of developing Alzheimer’s disease.
Scientists have even found evidence of toxins secreted by porphyromonas gingivalis in the brains of deceased Alzheimer’s patients. It is thought that these toxins may be capable of passing from the blood into the brain, where they cause structural damage over time. “There are more of these enzymes in the regions that we know are more damaged in Alzheimer’s disease, and less elsewhere,” says Dr Tomas Welsh, medical director of the Research Institute for the Care of Older People.
Drug companies have even attempted to develop therapeutics to block the activity of these toxins and prevent them reaching the brain, although so far this approach has had limited success.
Painful joints
Just like diabetes, having rheumatoid arthritis can worsen your oral health, while poor mouth hygiene can exacerbate this painful condition which causes swelling in the joints.
“The more inflammatory chemicals there are in your bloodstream, the more likely you are to have inflammatory problems,” says Woodhouse. “And if you have gum problems, your joint problems will be much worse.”
How gum disease affects the body
Brain
Toxins produced by certain gum bacteria can reach the brain, where they can damage the fragile structures connecting brain regions.
Lungs
Chronic gum infections can work their way down the respiratory tract and into the lungs. The inflammation caused by these bacteria can increase the risk of pneumonia.
Heart
Bacteria in the mouth release toxins that can cause the arteries to harden or stiffen. These microbes can even reach the heart via the bloodstream, causing inflammation.
Pancreas
An overload of gum bacteria can cause blood sugar levels to rise. This impacts the pancreas, making it harder for people with diabetes to keep the condition under control.
Joints
Inflammation from gum bacteria can reach the joints, worsening conditions like rheumatoid arthritis.