Brushing your teeth three times a day could improve mental health

Oral health is linked with the overall health of the body, but it is often overlooked by doctors. According to Elena Figuero, professor of dentistry at Madrid’s Complutense University in Spain, this oversight begins at university, when medical students are taught that the digestive system ends at the mouth. She is one of the many professionals trying to undo this perception: to varying degrees, there are more than 50 diseases that are caused by or worsened by periodontal disease.

Periodontal disease, unlike cavities, begins by affecting the gums – a condition known as gingivitis. If left untreated, gingivitis can lead to periodontitis, damage the bone and even cause teeth to fall out. “These diseases are caused by an imbalance between the patient’s bacteria and the immune response, which causes an excessive amount of pathogenic bacteria. These can reach the bloodstream and produce bacteraemia, and trigger an excessive inflammatory response with systemic effects,” says Figuero.

“Chronic inflammatory foci, even if they are of low intensity, such as in periodontal disease, can produce alterations that make the blood-brain barrier more permeable. This barrier protects the brain from dangerous elements,” says Juan Carlos Leza, from the Biomedical Health Center in Spain, which is aimed to exploring the biological bases of mental illness. “Inflammation is a necessary response, like stress, but when there is continuous, low-intensity inflammation, the risk of problems such as strokes can increase,” adds Leza, who is working with Figuero n a study on mice that looks at the relationship between periodontal disease and depression. “A causal relationship between having intestinal dysbiosis or a mouth disorder and having schizophrenia or suffering a stroke has not been proven, but it has been seen that people with these problems have more inflammation, also in the mouth.”

Last week, at the American Stroke Association International Stroke Conference 2023, researchers from the Yale School of Medicine presented a study that looked at the relationship between brain health and oral health. For the study, the researchers analyzed 40,000 adults without a history of stroke enrolled in the UK Biobank between 2014 and 2021. Participants were screened for 105 genetic variants known to predispose people to cavities, dentures and missing teeth later in life. Researchers then evaluated the relationship between those genetic risk factors and brain health, which was tested via MRI images. The study concluded that “people who were genetically prone to cavities, missing teeth or needing dentures had a higher burden of silent cerebrovascular disease.”

Some studies show that periodontal disease increase the risk of depression and Alzheimer’s, but the link between oral health and mental health is still being established. There is, however, a clear relationship between oral health and other diseases such as diabetes. “In diabetes, it has been seen that treating periodontitis is as effective as administering a second oral antidiabetic. So much so that it is possible to prevent the patient from having to take that second drug,” explains Figuero. “We are not there yet, but we would like to see if, in patients with depression and periodontitis, the parameters of mental illness improve when we treat them [for periodontal disease].”

The discovery of the relationship between oral health and the overall health of the body is part of a broader move away from specialization and make medicine more holistic. Better knowledge of the immune system and its relationship with the bacteria that inhabit the body seems to be improving the treatment of many conditions, including mental disorders, which are particularly misunderstood. “The idea is to treat the patient as a whole,” says Figuero, who says that an annual dental checkup to monitor the risk of periodontal disease is less expensive than treating it once it has advanced.

As well as regular checkups, there are other simple steps we can take to improve oral health and reduce the risk of other ailments. The main one is to brush your teeth with fluoridated toothpaste after meals to prevent cavities, and use floss daily. Taking care of your teeth, concludes Figuero, “not only prolongs life expectancy, but it lengthens the quality of life.”

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