Can a Root Canal Improve Your Overall Health? What a 2025 Study Found

For years, dentists have told patients that the mouth isn't sealed off from the rest of the body — that an untreated dental infection can ripple outward and affect systemic health. A 2025 study from King's College London, published in the Journal of Translational Medicine, is among the recent research measuring that ripple directly, by watching what happens in patients' blood after an infected tooth is properly treated with a root canal.

What did the study actually find?

Researchers followed 65 patients for two years after they received root canal treatment for apical periodontitis — a common infection at the tip of a tooth's root. Using a technique called NMR spectroscopy, the team measured dozens of molecules circulating in each patient's blood at five points over the two years.

The pattern was consistent. By the two-year mark, patients showed lower levels of glucose and pyruvate, pointing to better blood-sugar handling. Cholesterol and certain fatty acids dropped in the shorter term, and branched-chain amino acids — markers tied to insulin resistance and chronic inflammation — began falling within just three months of treatment. In plain terms: after the infection was resolved, several of the body's markers of metabolic and inflammatory stress moved in a healthier direction.

Why would treating one tooth change your blood chemistry?

Because an infected tooth isn't a local, contained problem. Apical periodontitis is a pocket of live bacteria and inflammation with a direct line to the bloodstream. The body responds to that low-grade, persistent infection the way it responds to any chronic inflammatory load — and that response shows up in circulating markers of sugar and fat metabolism.

When the infection is cleaned out and sealed during root canal treatment, that inflammatory source is removed. The King's College team's interpretation is that the improvements they measured reflect the body no longer having to fight the infection. It's the same logic behind why leaving an infection untreated is a genuine risk, not just a dental inconvenience — something we cover in what happens if you don't get a root canal.

Does this mean a root canal treats diabetes or heart disease?

No — and it's important to be precise here. The study did not test root canals as a therapy for diabetes, high cholesterol, or heart disease, and it does not show that a root canal will lower anyone's blood sugar as a treatment. What it shows is narrower and more honest: resolving a specific oral infection was associated with improvements in metabolic markers in the people studied.

The realistic takeaway isn't "get a root canal to improve your health." It's that an untreated infected tooth may be quietly adding to your body's inflammatory burden, and clearing it removes that load. If you have diabetes or heart concerns, that's one more reason not to postpone treating an infected tooth — but the study is not a substitute for medical care, and it doesn't change how any systemic condition should be managed by your physician.

What this means for you

If you have a tooth that's been flagged as infected — or you're weighing a root canal against pulling the tooth or "waiting to see" — this research is a useful data point: promptly resolving the infection appears to benefit more than just the tooth. It also reinforces why an infected tooth shouldn't be managed with repeated rounds of antibiotics alone, which don't remove the source (see antibiotics and tooth infections).

The best outcome comes from treating the infection thoroughly the first time. If you'd like a clear read on whether a tooth needs treatment and what to expect, our team is happy to help — and for most patients, resolving an infection sooner rather than later reduces the risk of it progressing.