Can Gum Disease Cause Heart Disease and/or Stroke? By Dr. Jeff Shnall
If your dentist has told you that you have gum disease, this is certainly not uplifting news. Gum disease can cause bleeding gums, pain, swelling and lead to tooth loss, if left untreated. However, can gum disease be a direct cause of heart disease or stroke?
If you search this question online, you will find that there are many articles suggesting that gum disease is indeed a direct cause of heart disease and stroke. However, there are probably just as many articles and studies online stating that gum disease does not cause heart disease or stroke.
My aim in this article is to provide some clarity to this question.
The short answer is there is no evidence or very weak evidence to support the notion that gum disease causes heart disease and stroke.
However, statistics show that if you have gum disease, you do have a higher chance of also developing heart disease and /or having a stroke.
You may be asking how can this be? I just said that that gum disease not cause heart disease or stroke but now I am saying if you have gum disease you have a higher chance of having heart disease or stroke.
If you are confused that is understandable because a lot of people writing on this topic are also confused.
Medical research has found that that both gum disease and heart disease/stroke have a common cause that leads to both conditions.
A simple everyday example showing the same faulty reasoning in people who claim there is a causal link between gum disease and heart disease/stroke is as follows: Statistics show that on days when the sale of umbrellas increase there is also an increase in the number of traffic accidents. But can we conclude that buying umbrellas causes car accidents?
Rather, both an increase in umbrella sales and an increase in car accidents have a common cause: they are both more apt to occur on rainy days. (I got this example from the website “The Straight Dope.”)
In the case of gum disease and heart disease/stroke, as I will explain below, the common cause is inflammation. Let's take a closer look at gum disease, heart disease and stroke and see if we can clear up some cause and effect confusion and as well give some advice on how to get your gums and heart healthier.
Figure 1: Gum Disease: red swollen gums
Gum disease is a common condition.
Mild to moderate gum disease affects 30 to 50 percent of adults in the US. The website of the Canadian Dental Association states that gum disease will affect 7 out of 10 Canadians over their lifetime.
Severe gum disease affects an estimated 5% to 15 % of the US adult population and almost one in three elderly. Canadian statistics are likely very similar.
Patients with gum disease may not have pain, at least initially but may notice some of the following:
Swollen, discoloured or bleeding gums especially when brushing or flossing
The teeth may look longer than they use to due to gum recession and bone loss
Development of spacing between the teeth, loose teeth or teeth that are sore to chew on
Bad breath or bad taste.
Our mouths are home to billions of bacteria of many kinds and when we brush and floss we are trying to remove or brush away the bacteria or plaque form our teeth. However, if you don’t brush or floss regularly or carefully, bacteria/plaque can build up on the teeth, starting the gum disease process.
Figure 2 The gum disease process
The gum disease process
Part (A) in figure 2 above shows a tooth surrounded by healthy gums. In part (B), clumps of bacteria (otherwise known as plaque) have attached and multiplied on the tooth surface and are extending under the gumline. In (C), the bacteria on the tooth has triggered the neighbouring gums to become inflamed or in other words, has triggered the process of inflammation.
Inflammation is part of our body’s defense system against foreign invaders such as bacteria and also is a mechanism that helps our body heal when our cells become damaged.
In (D) above, blood vessels in our gums release chemicals and white blood cells that attack and try to destroy the bacteria on the tooth.
These blood vessels also get leaky and release more fluid into the affected gums which can cause the gums to swell. The strong chemicals released by the inflamed gums not only destroy foreign invading bacteria, they also destroy the bone that surrounds and supports the tooth.
If the inflammatory process goes untreated around a tooth, the eventual result can be the loss of so much bone that the tooth needs to be removed.
What determines whether you will develop gum disease?
There are several factors that will determine whether you develop gum disease and some may surprise you:
It helps to keep your teeth clean. If you have a lot of plaque buildup on your teeth and don’t spend much effort keeping your teeth clean, you are at higher risk of developing gum disease.
However, a big determinant in whether you will develop gum disease is related to how your body responds to bacteria. We all react to bacteria differently. If you have a normal immune system, you may develop a bit of inflammation in response to plaque on your teeth but not much else happens.
However, research has shown that some people are hyper responders to bacteria. A hyper responder can have an exaggerated inflammatory response to bacteria or plaque on the teeth, setting off swelling in the gums, bleeding and loss of bone when there are amounts of plaque that would not cause much of any reaction in a person with a normal inflammatory response.
Hyper responders are found to have signs of chronic inflmmation, that is, inflammation in their body on an ongoing basis.
This explains a strange phenomena that we dentists see in our offices: we can see one patient who always comes in for their dental cleaning with their teeth covered in plaque and hard deposits of calcium yet their gums do not exhibit gum disease while the next patient who comes in may have far less buildup of bacteria/plaque on their teeth yet have red, swollen and bleeding gums.
It is not merely the plaque or bacteria on the teeth that causes gum disease. It is how that individual's immune system (their inflammatory response) reacts to the bacteria that determines whether gum disease will result.
What makes someone a hyper responder?
Hyper responders have an exaggerated inflammatory response to bacteria, irritants and foreign bodies. There are many factors that make someone a hyper responder. Genetics can play a role. Some people are simply more prone to inflammation due to their genetic makeup. And they may or may not have any of the other risk factors below.
Other factors that can make some people more prone to stronger inflammatory responses are:
Smoking, excess alcohol use, obesity and stress. These all can increase the inflammatory response in our bodies, including in our gums and can increase the risk of gum disease.
In order to answer our original question regarding the link between gum disease and heart disease and stroke, let us now turn our attention towards these latter two conditions.
One leading cause of heart attack and stroke is atherosclerosis, a condition in which the arteries narrow. Arteries are the blood vessels that carry blood, delivering nutrients and oxygen to all the cells of our body.
Arteries are composed of tissue and the walls of the artery are lined by living cells.
The living cells that line our arteries are in direct contact with our blood inside the artery and it is in this layer of cells that problems can start.
Figure 3 Atherosclerosis
Fig 3A shows a healthy artery with blood flowing through it unimpeded, the way that water flows through a garden hose.
Fig 3B: If irritants make their way into the bloodstream, they can lodge into the walls of arteries. One such irritant are small proteins called lipoproteins that carry fats in our bloodstream for use or storage in other parts of the body.
Fig 3C: Irritants such as lipoproteins that penetrate the lining of arteries can trigger an inflammatory response in which the body tries to wall off and contain the irritants. The walling off of the irritant causes thickening of the artery and narrowing of the artery.
The damaged cells that line the artery can also be plugged up with platelets, fat cells and other blood components that can further clog the artery and cause blood clots in the artery.
Figure 4 Left side: Healthy heart, no blockage in arteries supplying the heart. Right side: Blocked artery in the heart (Large arrow) with damage in heart tissue in are that has lost its blood supply.
If one of these clots should break away, it can travel further down the blood vessel and completely block it.
If this occurs in a blood vessel that supplies the heart, it can cause damage to the heart muscle and results in a heart attack. (See figure 4)
If the dislodged clump of cells in the artery flow down stream and block an artery supplying the brain, a stroke is the result. A stroke occurs when there is damage to brain cells in a region that have lost their blood supply. (See Figure 5)
Figure 5 Storke: Blockage in an artery in the brain causing damage to nearby brain tissue)
What increases your chance of having a heart attack or stroke?
There are a few factors that increase your chance of heart attack or stroke.
Just like in gum disease, research shows that the more prone you are to inflammation, the higher your risk of developing heart disease and stroke.
And the factors that increase the risk of having an exaggerated inflammatory response and therefore an increased your risk of heart disease are:
Genetics: some people have an innate tendency to be hyper inflammatory responders
Smoking, lack of exercise, excess alcohol use and obesity all increase the chronic inflammatory response in your body and as well increase the risk of heart disease and stroke.
Note: It was previously thought that a diet high in fat/cholesterol would result in cholesterol being digested and carried to the lining of the heart by small proteins in our blood. These cholesterol laden proteins were thought to enter the wall of arteries of the heart.
Current thinking suggests that it is not a diet high in cholesterol but instead, one high in highly refined carbohydrates such as sugar, high fructose corn syrup, white flour and even white rice that are the culprit in atherosclerosis.
These sugars and simple starches are digested, converted into triglycerides and then carried by small proteins (lipoproteins) through the circulation where they can lodge into the lining of arteries in the heart.
So what about the link between gum disease , heart disease and stroke?
Well, we have now discussed that these three health problems are found in people who have exaggerated inflammatory responses. In gum disease, the hyper inflammatory response causes gum disease and in the case of heart disease the hyper inflammatory response occurs in the arteries supplying the heart..
Given the fact that these three diseases have a common cause, inflammation, it is easy to confuse cause and effect when discussing the link between gum disease and heart disease.
I should note that some websites include claims that it is bacteria in gum disease that travels to the heart and causes blockages or plaques to build up in arteries. However, research shows that the blockages found in arthersclerotic arteries do not contain bacteria found in infected gums.
It is important to treat gum disease. Managing and treating gum disease has many benefits. It can help save your teeth. Loss of teeth can affect your ability to chew, can affect your appearance and can make you self conscious when you smile. It can affect your ability to eat anything you like rather than softer foods that denture wearers sometimes have to settle for. It can also help diabetics to have better control over their blood sugar levels. Diseased gums has been shown to raise blood sugar levels.
However, treating gum disease is not going to reduce your risk of heart disease or stroke.
In order to prevent heart disease and stroke, you need to get to the cause of the problem. Someone predisposed to heart disease will benefit from reducing the inflammatory response in their body. This can be done through diet, exercise, quitting smoking and reducing alcohol consumption, weight loss and managing stress.
In the following section, I will provide a summary of research articles that point to the role of inflammation in the development of heart disease, stroke and gum disease and how researchers, and physicians and dentists are trying to treat these diseases by combating inflammation .
Article #1: C-Reactive Protein Test to Screen for Heart Disease: Why Do We Need Another Test? Appeared in Harvard Health Publishing March 2017, Harvard Medical School
This article discusses how measuring inflammation in the body can be a better predictor regarding our risk of developing heart disease or stroke than knowing our LDL cholesterol levels.
When you go for your annual physical, your doctor may ask for a blood test to measure your cholesterol levels, including LDL and HDL cholesterol in order to assess your heart health. However only 50% of people who have heart attacks have high levels of LDL cholesterol in their blood, so the theory that high cholesterol levels lead to heart disease does not seem to adequately explain heart disease.
The article supports the belief that high levels of inflammation appear to be causative in heart disease and that trying to reduce inflammation is one way of trying to prevent heart disease.
C-reactive Protein (CRP) is a protein found in higher amounts in the blood in people who have higher levels of chronic inflammation (hyper inflammatory responders). By measuring your CRP, predictions can be made regarding your risk of developing gum disease and heart disease. (High CRP blood test results may put you in a higher risk category for inflammatory diseases).
Article # 4: Inflammation and Heart Disease: What Is C-Reactive Protein? Who Might Benefit from Testing? Appeared in: European League Against Rheumatism June 16, 2017 By Jan Griffin, M.D. and Erin Michos, M.D., M.H.S.
Dr. Jan Griffin is a postdoctoral clinical and research fellow in cardiology at the Johns Hopkins University School of Medicine. Dr. Erin Michos is a cardiologist and associate professor of medicine at the Johns Hopkins University School of Medicine
Article #5: Clinical And Systemic Implications Of Periodontal Disease Susceptibility: The Importance Of IL-6 Polymorphism Author: Herbert I Bader DDS, FACD, m FICD Clinical Associate, Harvard School of Dental Medicine Published : January 02, 2014 in the journal Dentistry
This article discusses patients with a hyper inflammatory reaction to bacteria on the teeth are more likely to develop gum disease than normal inflammatory responders. This article discusses a saliva test that can spot people with the genetic tendency to a hyper inflammatory response so that preventive measures can be employed before the patient develops gum disease or heart disease.
Article # 6 This is a link to a few paragraphs from a popular textbook on gum disease that explains the relationship between hyper inflammatory responders and gum disease and heart disease. Textbook: Clinical Periodontology 10th edition By Dr. Michael Newman (et al. chapter 18).
To conclude, the scientific evidence available points to a common cause for both gum disease, heart disease and stroke. These diseases are more likely to be caused by other factors such as a genetic tendency to be a hyper responder to bacteria, or other shared causes such as smoking and poor dietary and exercise practices.
Taking steps to reduce inflammation can be an important way to prevent gum disease and heart disease/stroke.
How is gum disease traditionally treated? The aim is to eliminate inflammation in the gums and to heal diseased gum tissue and bone. Here are some of the ways gum disease is treated:
Professional cleanings by a dentist or dental hygienist to remove the bacterial coating and calcium deposits above and below the gum line.
Teaching patients to keep their teeth as bacteria-free as possible through proper brushing and flossing technique
Antibacterial rinses, antibiotics, gum surgery or sometimes extraction of one or more teeth is needed.
Research has proven that if patients can keep their teeth very clean at home, and if they see their dentist regularly this can help prevent or reduce the severity of gum disease.
Also, as discussed in this article, reducing generalized inflammation in the body can also play a role in controlling gum disease, especially reducing or eliminating smoking. A future article in this series will explore ways of reducing inflammation as it relates to dental and overall health.
Some additional sources:
The American Journal of Cardiology and Journal of Periodontology Editors' Consensus: Periodontitis and Atherosclerotic Cardiovascular Disease, July 2009, Vol. 80, No. 7, Pages 1021-1032Vincent E. Friedewald,* Kenneth S. Kornman, et al. The link to this highly technical article is: http://www.joponline.org/doi/full/10.1902/jop.2009.097001