Gum Disease and Diabetes: The Two-Way Relationship

A Relationship That Runs Both Ways

Periodontitis is a chronic inflammatory disease that slowly destroys the ligament and bone holding your teeth in place. It's common, with severe periodontitis affecting an estimated 10 to 15% of adults. Diabetes is one of its biggest known risk factors: a widely cited review in the journal Diabetologia estimates that people with diabetes are roughly three times more susceptible to periodontitis, and the higher someone's blood sugar runs, the more severe their gum disease tends to be.^[1]

What makes this relationship unusual is that it doesn't only run in one direction. A 2018 consensus report from the International Diabetes Federation and the European Federation of Periodontology found strong evidence that people with periodontitis have a higher risk of abnormal blood sugar and insulin resistance. Among people who already have diabetes, those with periodontitis tend to have higher HbA1c (the blood test that reflects average blood sugar over roughly three months) than those with healthy gums, and periodontitis is also associated with a higher risk of developing type 2 diabetes in the first place.^[2] The same report noted that most of this evidence comes from type 2 diabetes, and there isn't enough data yet to say the same with confidence for type 1.

The consequences reach beyond the mouth. The CDC reports that adults aged 50 or older with diabetes have severe tooth loss 56% more often than similar adults without diabetes, and that treating gum disease significantly improves blood sugar control compared with no treatment or routine care.^[3]

How Diabetes Harms the Gums

Gum disease starts with bacteria in plaque, but how much damage that plaque causes depends heavily on how the body responds to it. Diabetes changes that response in several ways.

An overactive, slow-to-settle immune response. Research summarized in Nature Reviews Endocrinology shows that diabetes leads to an exaggerated inflammatory reaction to gum bacteria, and also impairs the body's ability to wind that inflammation down and repair the tissue afterward. The result is faster destruction of the gums and the bone underneath.^[4]

Advanced glycation end products (AGEs). When blood sugar stays high for long periods, sugar molecules attach to proteins and fats in the body, forming compounds called advanced glycation end products. These build up in tissues, including the gums. The same review describes how the receptor for AGEs, known as RAGE, and the molecules that bind to it are found in the gum tissue of people with diabetes, and appear to help drive that exaggerated inflammation and poor healing.^[4] In plain terms, years of high blood sugar can leave the gums primed to overreact to bacteria that a healthy mouth would handle more calmly.

Changes in saliva. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), diabetes can reduce saliva and raise the amount of glucose in it. Saliva normally washes away food, limits bacterial growth, and counters the acids bacteria produce, so less of it makes both cavities and gum disease more likely.^[5] If dry mouth is part of the picture for you, our guide to dry mouth and gum health covers it in more depth.

How Gum Disease May Push Blood Sugar Up

The reverse direction is less obvious but has a reasonable explanation. Periodontitis is not just a local problem. Inflamed gum pockets release inflammatory signalling molecules into the bloodstream, and the 2018 consensus report identified raised levels of interleukin-1 beta, tumour necrosis factor alpha, interleukin-6, oxidative stress, and related immune signals as key mechanistic links between the two diseases.^[2]

Several of those same molecules are known to interfere with how cells respond to insulin. The Nature Reviews Endocrinology review describes the likely chain this way: periodontal infection raises body-wide inflammatory mediators, and those mediators make insulin resistance worse.^[4] When cells respond less well to insulin, blood sugar rises, which in turn feeds the AGE and inflammation problems described above. That is the loop people mean when they call this a two-way relationship.

There are also signs that gum disease may matter for diabetes complications. The Diabetologia review cites studies in which people with diabetes and severe periodontitis had roughly two to three times higher rates of serious kidney problems, and about three times higher risk of death from heart and kidney disease combined, than people with diabetes but without severe periodontitis.^[1] These are observational findings, so they show an association rather than proof that gum disease causes those outcomes. Smoking, age, and how long someone has had diabetes can all play a role. The cardiovascular side of this story is covered in our guide to gum disease and heart disease.

Does Treating Gum Disease Improve HbA1c?

This is where the diabetes connection is on firmer ground than most "mouth and body" links, because it has been tested in many randomized trials.

The strongest summary is a 2022 Cochrane review led by Terry Simpson. It pooled 35 randomized trials with 3,249 participants, almost all with type 2 diabetes, comparing professional periodontal treatment (mainly deep cleaning below the gumline, known as scaling and root planing or subgingival instrumentation) against no treatment or usual care. Based on moderate-certainty evidence from 30 of those studies, treatment lowered HbA1c by an average of 0.43 percentage points three to four months later. The reduction was 0.30 points at six months, and 0.50 points at 12 months in the one study that followed people that long.^[6]

The reviewers described this as a clinically significant improvement, and said further trials of this kind were unlikely to change the overall conclusion. That's a notable shift: earlier versions of the same review were much less certain. Harms were generally reported as none or mild, though the authors pointed out that most trials didn't measure side effects carefully.^[6]

The single 12-month trial in that analysis, published in The Lancet Diabetes & Endocrinology in 2018, randomly assigned 264 people with type 2 diabetes and moderate to severe periodontitis to either intensive periodontal treatment with follow-up cleanings every three months, or basic above-the-gumline scaling and polishing. After a year, and after adjusting for factors such as age, smoking, and diabetes duration, HbA1c was about 0.6 percentage points lower in the intensive-treatment group.^[7]

A few honest caveats are worth keeping in mind:

• It's an add-on, not a replacement. Gum treatment works alongside diabetes medication, diet, and activity. Nobody should change their diabetes treatment because they've had a dental cleaning.
• Long-term data are thinner. Most trials ran three to 12 months. The 2018 consensus report noted that studies with longer follow-up were inconclusive at the time.^[2]
• Type 1 diabetes is understudied. Nearly all the trial evidence comes from people with type 2 diabetes.^[6]

Practical Steps if You Have Diabetes

Given the evidence, researchers have argued that oral and gum health should be treated as an integral part of diabetes management, and the International Diabetes Federation and European Federation of Periodontology have issued joint guidance on managing the two conditions together.^[1][2] Yet the CDC reports that about 60% of US adults with diabetes saw a medical provider in the past year but didn't have a dental visit.^[3] If that sounds familiar, these steps are a good place to start:

• Keep blood sugar in your target range. NIDDK lists this first, since high blood glucose directly worsens mouth problems.^[5]
• Tell your dentist you have diabetes. Share your medicines and any changes in your health, and ask how often you should come in for cleanings and checkups based on your own risk.^[5]
• Know the warning signs. Red, swollen, or bleeding gums, gums pulling away from teeth, loose teeth or widening gaps, and ongoing dry mouth or bad breath are all reasons to book a visit.^[5] Our guide to gum disease stages explains what each stage looks like.
• Brush and floss every day. Use the cleaning tools and products your dentist recommends for your mouth.^[5]
• If you smoke, get help quitting. The CDC notes smokers have twice the risk of gum disease and that gum disease treatment may not work as well for people who smoke.^[8]
• Treat a periodontitis diagnosis as part of your diabetes plan. If your dentist finds periodontitis, getting it treated and keeping up maintenance visits may help your HbA1c as well as your teeth.^[6] It's also worth letting your doctor know.

A Daily Gum-Care Habit Worth Adding

Steady daily gum care matters, and it fits right alongside your usual diabetes care and dental visits. DentaBiome is a daily oral postbiotic Berry Frost chewable designed to support gum comfort and a balanced oral microbiome. The 60-day money-back guarantee makes it risk-free to try. As with any supplement, check with your doctor or pharmacist first if you have diabetes.

See DentaBiome and the 60-day guarantee →

Affiliate link. The official page has the current packages and refund terms.