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Oral and Systemic Health Link


The oral cavity is packed with bacteria, mostly harmless. With good oral hygiene, these germs are in a controlled environment and does not pose any problem. Gum disease will only occurred when oral hygiene care is not satisfactory.

This infection produces inflammation of the gums and our understanding now is that the link of gum disease and other diseases of the body is due to this inflammation, not bacteria as believed earlier.

The concept of oral infection influencing the body health has been postulated in the 1920s. However, the idea was not well accepted and it has only been revisited in the past two decades. Research has shown, and experts agree, that there is an association between poor oral health and other chronic inflammatory conditions of the body.

Gum disease

Gum (periodontal) disease is by far the most common oral infection. It is a group of conditions that cause inflammation and loss of teeth. Gum disease is caused by bacteria found in dental plaque with chronic infection and inflammation.

Inflammation has been found to be the common factor in gum disease and the other systemic diseases. There is both a local inflammatory response in the gums and a systemic inflammatory response throughout the body in people who also suffer from one of the diseases linked to gum disease.

Furthermore, both gum and systemic diseases share common risk factors such as smoking, impaired immune system function, obesity and high stress.

Systemic diseases that may be linked with gum disease


People with diabetes are more likely to have gum disease, probably because of the body’s reduced resistance to infection. In fact, gum disease may be considered as one of complications of diabetes. People who have uncontrolled diabetes may develop more frequent and severe infections than do people who have good blood sugar control.

Research has suggested that the relationship between gum disease and diabetes goes both ways. Gum disease may make control of blood sugar more difficult among people who have diabetes. It is because infection anywhere in the body can raise the blood sugar level, requiring more insulin to keep it in check. This contributes to increased periods of time when the body functions with a high blood sugar thus increasing the risk for diabetic complications.

Cardiovascular disease (e.g. Heart disease and stroke)

There is increasing evidence that chronic infections such as gum disease are associated with cardiovascular diseases. Having long-term gum disease may increase the risk of heart attack and stroke. Research suggests that the bacteria and chemicals from gum disease can travel through the bloodstream to the blood vessels of the heart and other parts of the body. They could trigger a cycle of inflammation and with narrowing of the blood vessels. This contributes to heart attacks and strokes. Oral bacteria can also cause blood clots, thus, increasing the likelihood of strokes.

Many researchers and clinicians think that inflammation is even more harmful to the cardiovascular system than the most established, classic risk factors, such as high LDL cholesterol. The link between inflammation and heart disease helps explain why almost half of all people who develop heart disease do not have any of the well-known risk factors for the disease, other than high levels of inflammation.

Therefore, it makes sense for people who are worried about cardiovascular disease to have healthy gums. This may be just one way to prevent cardiovascular disease, but it appears to be a very important way. Besides, it is not as demanding as other preventive measures, such as losing weight or exercising.

Complications of pregnancy

All infections including gum disease are causes for concern among pregnant women because they pose a risk to the health of the baby. Pregnant women who have gum disease may be more likely to have a baby that is born too early and with low birth weight. However, the exact association is not clear. More research is needed to confirm how gum disease may affect pregnancy outcomes.


Recent research suggests that bacteria found in the throat and mouth, can be drawn into the lower respiratory tract. This can cause infections or worsen existing lung conditions. An increase in dental plaque may place these individuals to be at greater risk for respiratory infections especially in people with severe compromised health, in frail elderly people and in patients with chronic pulmonary disease.  People with respiratory diseases, suffer from reduced protective systems, making it difficult to eliminate bacteria from the lungs. Having serious gum disease and lung problems, inhaling (aspirating) bacteria from the mouth into the lungs may result in aspiration pneumonia, a condition that’s especially common in hospitals where patients may be sedated or have tracheal tubes. Improving oral hygiene might reduce the risk of pneumonia among people at risk.


Missing teeth and gum disease at an early age may be linked to an increased risk of Alzheimer’s disease, bolstering the increasingly strong connection between early exposure to chronic inflammation and this degenerative brain disorder.

A study of 100 sets of twins in the United Kingdom (where one had Alzheimer’s and the other one didn’t) found that if the person had moderate to severe gum disease prior to age 35, chances of getting Alzheimer’s increases five times.

New York University dental researchers have found the first long-term evidence that periodontal (gum) disease may increase the risk of cognitive dysfunction associated with Alzheimer’s disease in healthy individuals as well as in those who already are cognitively impaired.

Renal (kidney) disease

Chronic bacterial infection of the oral cavity is a possible risk factor for cardiovascular disease (CVD). Given the numerous shared risk factors for cardiovascular disease and chronic kidney disease, it is also possible that gum disease is associated with renal insufficiency

Pancreatic cancer

A new study has found that gum disease may be associated with increased risk of cancer of the pancreas. This study provides the first strong evidence that gum disease may increase the risk of pancreatic cancer. It was conducted by researchers at the Harvard School of Public Health (HSPH) and Dana-Farber Cancer Institute (published in the Journal of the National Cancer Institute).The results of the study showed that, men with gum disease had a 63 percent higher risk of developing pancreatic cancer compared to those reporting no gum disease (after adjusting for age, smoking, diabetes, body mass index and a number of other factors). It was also found that non-smokers suffering from gum disease had a two-fold increase in risk of pancreatic cancer.


Systemic health is closely linked to the state of the oral cavity.  People with gum disease have been shown to be at increased risk of other systemic diseases. It is still not clear how the diseases interact. Until more research becomes available, patients with gum disease should try to reduce their risk factors and take preventive measures. The best way to avoid having gum disease is by practicing good oral hygiene. Daily brushing with flossing and regular check-ups can greatly reduce the chance of developing gum disease and may even improve overall health.

Last Reviewed : 25 April 2014
Writer : Dr. Rosrahimi bt. Abd Rahim
Accreditor : Datin Dr. Sorayah bt. Sidek
Reviewer : Dr. Ahmad Sharifuddin b. Mohd Asari