What is the link between gum disease and heart disease?
The link between gum disease and heart disease has been found consistently across dozens of studies, but whether it is truly causal has not yet been established. Even so, good oral care is worthwhile in its own right, regardless of the question about the heart.
People with severe gum disease demonstrably have a higher risk of cardiovascular disease. All 41 systematic reviews in a broad umbrella analysis found this association. The increase in risk ranges from a 22% higher chance to well over four times the normal risk, depending on the condition and the study. It is not limited to a single heart condition: elevated risks have been found for coronary artery disease, atrial fibrillation, high blood pressure, heart failure, and peripheral artery disease.
How this association arises has not yet been fully explained. Gum disease causes a lingering, chronic inflammation that is also measurable in the blood. Bacteria from the gum pocket can reach the bloodstream and potentially damage the inner lining of blood vessels, contribute to plaque formation in arteries, and increase the tendency for blood clotting. This sounds mechanistically plausible, but has so far been demonstrated mainly in laboratory and animal research, not conclusively in humans.
Whether this association is truly causal is not certain. Genetic studies that test causal relationships found no genetic evidence that gum disease directly causes atherosclerosis. A further complication is that gum disease and heart disease share many common risk factors: smoking, ageing, diabetes, and an unhealthy lifestyle both raise the risk of each. It is difficult to separate out the independent contribution of gum disease.
Gum treatment demonstrably lowers certain blood markers that reflect heart risk, such as inflammatory markers. However, whether that treatment actually reduces the number of heart attacks or strokes has not yet been shown in large studies. People who use blood thinners need to take extra care around gum treatments.
Based on multiple meta-analyses and an umbrella review (PMID 39468505, 32011025, 30897827, 38141902) supplemented by mechanistic and Mendelian randomisation studies (PMID 39515611, 29903685, 30987702, 39494478). The association is epidemiologically robust; causality has not been proven.