Your Mouth Could Hold the Secrets to a Longer and Healthier Life (WSJ)

The eyes are a window to the soul, but the mouth may reveal just as much about a person’s health—and the diseases that shape how we age.

To better understand those connections, scientists are studying how issues that start in the mouth may contribute to chronic inflammation elsewhere in the body. In particular, they’re examining how bacteria from diseased gums, and the immune response they trigger, may contribute to conditions including heart disease, diabetes, cognitive decline, arthritis, respiratory disease and chronic liver disease.

The emerging science poses a challenge for healthcare, given the traditional divide between medicine and dentistry—fields that have long been divided by separate training, records and insurance systems. “Dentists haven’t traditionally been trained to think about whole-body health in relation to the mouth, and doctors haven’t been trained to see dental health as a first step to overall well-being,” says Dr. Jessica Lederhausen, a dentist and author of “Oral,” a book exploring the role of lifestyle on oral health.

But that is changing. Dental schools, which have taught how diseases like diabetes affect the mouth, are also placing greater emphasis on how oral disease can affect the rest of the body. Medical-education leaders have called on medical schools to better integrate oral health into physician training**.**

At the Harvard School of Dental Medicine, the Initiative to Integrate Oral Health and Medicine is researching how oral-health policy and health-system design can better support “whole-person care,” according to its director, Dr. Lisa Simon, who is both a dentist and a physician.

“We envision a future where a heart doctor asks patients if they are seeing their dentist regularly, and whether they are aware their periodontal disease could mean they have a much worse heart situation,” says Wenyuan Shi, an oral-microbiology researcher who heads the ADA Forsyth Institute, the research arm of the American Dental Association.

With better coordination, including shared medical and dental records, experts say, primary-care doctors might increasingly refer patients with diabetes or at high risk for heart disease to a dentist or periodontist for evaluation and treatment of gum disease. Meanwhile, more dentists may identify signs of uncontrolled diabetes and coordinate care with the patient’s physician.

The longevity link

The growing understanding of the mouth-body connection is also leading to new diagnostic tools, prevention strategies and treatments. And it is intensifying calls to provide more widespread coverage for preventive dental procedures, especially for older adults who are at highest risk.

According to the Centers for Disease Control and Prevention, nearly half of all adults aged 30 years and older have periodontitis, the more serious type of gum disease that involves bone loss around teeth. But federal data also shows prevalence increases with age, when close to 60% of those 65 or older have some level of disease—just as people become more vulnerable to conditions that can dramatically affect a healthy lifespan. In turn, conditions such as diabetes can make gum disease more severe or harder to treat.

A 2023 review in the journal Biogerontology concluded that oral health plays a significant role in reaching “exceptional longevity,” in part because of its connection to inflammation. And research on adults 65 and older has found that oral diseases—including periodontal disease, tooth decay and tooth loss—remain a substantial source of years lived with disability, suggesting that oral health can shape the quality, not just the length, of later life.

Read the full story: Your Mouth Could Hold the Secrets to a Longer and Healthier Life (WSJ)

A full summary of the 2023 Review from the Biogerontology journal.

The rosetta stone of successful ageing: does oral health have a role?

Ageing researchers have spent two decades building a shared language for why bodies fall apart, the so-called hallmarks of ageing, covering everything from DNA damage to chronic inflammation. This review argues that one obvious organ system keeps getting left off the list: the mouth. The authors make the case that oral health, and periodontal disease in particular, sits at a busy crossroads of nutrition, inflammation and metabolic control, and that ignoring it leaves a hole in our models of how people reach 100. Their central metaphor is the Rosetta Stone: oral health could be the translational key that connects dental medicine to the biology of extreme longevity.

We have grown used to the idea that living to 100 is about genes, diet, exercise and keeping inflammation low. A team from Leipzig and Exeter now argues that longevity science has a blind spot hiding in plain sight, right behind the lips.

Their review pulls together two fields that rarely talk to each other. On one side is the mature science of ageing, organised around the widely cited hallmarks of ageing, a checklist of cellular failures including genomic instability, worn-out telomeres, deranged nutrient sensing, failing mitochondria, senescent cells and chronic low-grade inflammation. On the other side is dentistry, which has quietly accumulated evidence that gum disease is not a local nuisance but a systemic event. Bacteria and inflammatory molecules from diseased gums can enter the bloodstream, worsen insulin resistance, feed the fatty plaques of heart disease, and disturb the gut.

The big idea is that these two stories are the same story. Centenarians, the authors note, share one striking trait: they suppress inflammation for most of their lives and only let it rise near the very end. Periodontal disease is fundamentally an inflammatory disease. So the ability to keep gums healthy might be a visible, measurable readout of the same deep capacity that lets some people avoid the inflammatory spiral of ageing altogether. In that framing, a healthy mouth is not just cause but also a window, a surrogate marker for how well the whole body handles inflammation.

There is a practical loop too. Reaching very old age requires eating well, and eating well requires teeth. Poor chewing function reduces protein intake, which accelerates muscle loss and frailty, which drives mortality. The mouth, in other words, guards the front door of nutrition.

The review is careful to admit how thin the direct evidence is. Almost no centenarian studies have measured oral health properly. Most dental-ageing data come from people under 100, so they may not apply to the exceptional oldest old at all. The authors are not reporting a discovery; they are pointing at a gap and asking the field to fill it, ideally by adding a dental exam and inflammatory blood markers to the same home visit when researchers finally sit down with the world’s centenarians. It is a hypothesis with a good story and, so far, very little proof. [Confidence: High that this fairly represents the paper]

Actionable insights

Because this is a hypothesis paper, the take-home messages are indirect, drawn from the primary studies it cites rather than from anything the authors tested. With that caveat, the practical thread is real.

Protect chewing function to protect nutrition. The review’s strongest applied claim is that poor masticatory function lowers protein intake, and low protein intake accelerates frailty and mortality. Effect size context from the cited literature: edentulousness (total tooth loss) in the elderly runs between 22 and 64 percent across populations, and it is named as an important risk factor for malnutrition. The practical lever is ordinary and unglamorous: keep your teeth, treat gum disease early, and maintain protein intake as you age.

Treat gum disease as metabolic medicine. In non-diabetics, periodontitis is associated with higher HbA1c and higher risk of progressing to pre-diabetes and diabetes; in diabetics it worsens glycemic control and complication rates. The relationship is bi-directional, so treating one may help the other.

Borrow the centenarian lifestyle. The review repeats the Blue Zones playbook that has the most support: eat in moderation and mostly plants, move daily, stay socially connected. It cites an estimate that Okinawan centenarians lived on roughly 11 percent caloric restriction across their lifetime. These are population correlations, not proven causes, but they are low-risk. [Confidence: Medium; associations, not proven interventions]

Context and source

  • Open Access Paper: The rosetta stone of successful ageing: does oral health have a role? (pdf)
    Authors: Maximilian Poser, Katie E. A. Sing, Thomas Ebert, Dirk Ziebolz, Gerhard Schmalz.
  • Institutions and countries: University of Leipzig, Germany (Department of Cariology, Endodontology and Periodontology; and Medical Department III, Endocrinology, Nephrology, Rheumatology); and Royal Devon and Exeter Hospital, University of Exeter Medical School, United Kingdom.
  • Journal: Biogerontology, 2023, volume 24, pages 867 to 888.
  • Article type: Narrative review.
  • Journal impact evaluation: The impact score of this journal is 4.6 (2023 Journal Impact Factor; CiteScore 7.1), therefore this is a Medium impact journal. In fairness to the venue, Biogerontology is a respectable specialist journal in the ageing field rather than a general-science flagship, so a mid-single-digit impact factor is normal for its niche and should not by itself be read as a mark of weak work.