The mouth is often described as a window to overall health - and for good reason. A growing body of research reveals a significant link between poor dental hygiene and cardiovascular disease. While these two areas of health may seem unrelated, the condition of your oral health can have far-reaching effects on the heart.
Author
- Steven W. Kerrigan
Professor of Precision Therapeutics, School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences
Gum disease and oral infections can trigger inflammation, allow harmful bacteria into the bloodstream, and, in severe cases, even lead to direct infection of heart tissue. Together, these effects can contribute to serious , sometimes life-threatening, cardiovascular conditions.
At the centre of this connection lies periodontitis - a severe form of gum disease caused by long-term plaque buildup and inadequate oral hygiene. Left untreated, plaque irritates and inflames gum tissue, eventually causing it to recede and deteriorate.
This breakdown gives oral bacteria easier access to the bloodstream. Everyday actions like brushing, flossing, or chewing - and especially dental procedures - can provide a pathway for these microbes to travel through the body.
Once in the bloodstream, certain bacteria can attach to the endothelium, the inner lining of blood vessels. This disrupts the vascular barrier, making it easier for infection to spread throughout the body, including to vital organs. In extreme cases, this can lead to organ failure - or even death.
Inflammation and infection
Systemic inflammation is one of the main ways oral health affects heart health. Chronic periodontitis triggers a prolonged immune response, increasing levels of key inflammatory markers such as C-reactive protein and cytokines.
These molecules can damage blood vessel linings and contribute to the development of atherosclerosis - a condition that narrows arteries, raises blood pressure and dramatically increases the risk of heart attacks and strokes.
Inflammation is now recognised not only as a symptom of cardiovascular disease but also as a driving force behind it. This insight elevates oral care from a cosmetic concern to a critical aspect of heart disease prevention.
Poor oral hygiene can also increase the risk of infective endocarditis (IE), a serious infection of the heart's inner lining or valves. This condition typically occurs when oral bacteria - especially from the streptococcus viridans group -enter the bloodstream and colonise damaged areas of the heart.
People with pre-existing valve abnormalities, prosthetic valves, or congenital heart defects are particularly vulnerable. For patients with prosthetic valves or certain heart conditions, dentists may even recommend antibiotics before specific procedures to minimise the risk of infective endocarditis. IE is a medical emergency requiring prolonged antibiotic treatment or, in some cases, surgery.
Epidemiological studies support this oral-cardiac link. People with gum disease are significantly more likely to suffer from heart disease. While these studies can't always prove direct causation, the correlations are strong - even after accounting for shared risk factors like smoking, diabetes and poor diet.
One study found that people with periodontitis were up to twice as likely to develop coronary artery disease compared to those with healthy gums. Other studies point to a "dose-response" effect: the more severe the gum disease, the greater the cardiovascular risk.
Oral microbiome
Smoking, unhealthy diets, excessive alcohol consumption and diabetes all contribute to both poor oral health and heart disease. Tobacco weakens gum tissue and suppresses immune function. Alcohol can dry out the mouth and disrupt the oral microbiome. And poorly controlled diabetes impairs circulation and slows healing, worsening both periodontal and cardiovascular conditions.
This overlap doesn't make the research less meaningful - in fact, it strengthens the case for addressing health holistically. Healthy habits benefit the whole body, not just isolated systems.
Emerging research also suggests that oral hygiene may influence heart health through changes in the body's microbiome. A poorly maintained mouth allows harmful bacteria to overtake beneficial microbes, causing an imbalance known as dysbiosis. This can disrupt immune function and contribute to chronic inflammation and atherosclerosis.
To be clear, good dental hygiene alone won't eliminate heart disease risk. Genetics, diet, exercise and underlying conditions all play crucial roles. But maintaining oral health is a simple, effective and often overlooked part of preventive health care. Regular brushing and flossing, routine dental visits and prompt treatment of gum disease can all reduce the risk of systemic complications.
Increasingly, health professionals are recognising the importance of collaboration . Cardiologists are being encouraged to ask about oral health, and dentists are urged to consider cardiovascular risk factors during checkups. This integrated approach can lead to earlier detection, more personalised care, and better long-term outcomes.
The mouth is far more than just the beginning of the digestive system - it plays a vital role in overall wellbeing. The connection between oral health and heart disease underscores the need to treat oral care as a foundational part of preventive medicine. By brushing up on good habits, individuals can protect not only their smile - but their heart, too
Steven W. Kerrigan receives funding from Science Foundation Ireland, Health Research Board of Ireland, Irish Research Council and Enterprise Ireland .
