Take care of your teeth and gums. Oral health can affect your brain.
By Richard Sima
Mental disorders are indeed an expanding threat, which requires raised awareness, education, prevention, and treatment initiatives nationally and globally. Experts have established that there are relationships between oral health and mental health disorders and the importance of oral health in mental health disorders. Do you hear me right? Yes. You do. Poor oral hygiene is associated with an increased risk for myriad health problems, including heart disease, diabetes, cancer, rheumatoid arthritis and early death. The state of our teeth and gums, though, may be vital for our well-being beyond the mouth and body.
Emerging evidence suggests that what goes on in our mouth can affect what goes on in our brain — and may even potentially affect our risk for dementia. Your mental health affects the health of your whole body, including your oral health. People who have mental health problems are more likely to have oral health conditions like teeth and gum problems. Good oral health also affects your overall health and can help improve your mental health.
“People should really be aware that oral health is really important,” said Anita Visser, professor in geriatric dentistry at the University of Groningen in the Netherlands.
Severe periodontal disease — chronic inflammation of and damage to the gums and bone that support the teeth — affects about 19 percent of people older than 15 or more than 1 billion people worldwide, according to a 2022 World Health Organization report. More research is needed, but recent observational studies have suggested that oral health may be a modifiable risk factor for Alzheimer’s, the most common type of dementia.
Scientists are still working out whether and how the health of our mouths and minds meld, but they have identified two potential culprits that might explain how gum disease could lead to Alzheimer’s disease: bacteria and inflammation.
Connecting dental and mental health
One of the first studies to document the link between gum disease, tooth loss, and Alzheimer’s disease focused on a cohort of aging nuns who were part of a larger study on aging. Researchers tracked 144 of the nuns and found that severe tooth loss was associated with a dementia risk up to 6.4 times higher than that with those who lost fewer teeth.
Other more recent longitudinal studies also found that a higher incidence of tooth loss was associated with cognitive decline. In one small 2016 study of 60 patients with mild to moderate dementia, periodontitis was associated with a sixfold increase in cognitive decline.
Another study in 2017, of almost 28,000 Taiwanese patients reported that having chronic periodontal disease for 10 or more years corresponded to a 1.7 times increase in the risk for Alzheimer’s disease. A 2022 meta-analysis of 47 longitudinal studies reported that tooth loss and poor oral health are associated with both cognitive decline and dementia.
This research paints an emerging picture of an association between poor oral health and dementia, but there are a number of confounding factors that prevent researchers from drawing definitive conclusions of causation.
The higher rate of dental problems among those with dementia may be a symptom rather than a cause of cognitive decline. People with dementia have a difficult time maintaining their oral health and have an increased risk of developing gum disease, meaning that the association between oral and cognitive health may be bidirectional.
Other known risk factors for dementia, such as smoking and lower educational levels, are also associated with worse oral health. Tooth loss has secondary effects that can affect nutrition and overall health, which can also affect cognition, Mario Dioguardi, a researcher in dental science at the University of Foggia, said in an email.
“It’s really complicated,” said Visser, who wrote a recent review on the association of oral health and Alzheimer’s. “And this is why we cannot say, ‘Oh, if you have periodontitis, you will get Alzheimer’s disease.’ But we know now that if you have severe periodontitis, the chance of getting Alzheimer’s disease is bigger.”
Mouth bacteria may infect the brain
Research has found that bacteria that normally reside in our mouth may also infect the brain and potentially contribute to neurodegeneration in Alzheimer’s disease.
A 2019 study published in Science Advances reported that the DNA of P. gingivalis bacteria, a key pathogen in gum disease, could be found in brain autopsies from Alzheimer’s patients. Bacterial DNA was also detected in the cerebrospinal fluid of people living with a probable Alzheimer’s disease diagnosis.
Toxic enzymes from the P. gingivalis bacteria were also found in the Alzheimer’s patients’ brains and correlated with the amount of tau protein pathology, a hallmark of the disease.
Orally infecting mice with the bacteria led to the presence of P. gingivalis DNA as well as the accumulation of amyloid β cellular waste—a hallmark of Alzheimer’s disease—in their brains.
The researchers were able to inhibit the bacterial enzymes in mice infected with P. gingivalis, which reduced amyloid β production and neuroinflammation. (A recent clinical trial targeting those bacterial enzymes fell short, however, and the Food and Drug Administration placed a hold on future trials.)
“The mechanisms through which periodontal bacteria can access the central nervous system remain unknown” but could reach the brain through circulation in the blood or along peripheral nerves, wrote Dioguardi, who was a co-author on a recent review on the role gum disease and oral bacteria play in Alzheimer’s.
Mouth inflammation can affect the brain
If we do not brush our teeth for several days, each tooth develops a thin biofilm called dental plaque that teems with acid-producing bacteria.
“Your body doesn’t like these bacteria,” Visser said. “They’re on the edge of your teeth and on the edge of your gum.”
With plaque buildup comes inflammation of the gums as our immune system tries to fight off the infection. Gingivitis, the mildest form of periodontal disease, is still reversible; brushing and removing the plaque buildup will allow the gums to heal.
But more severe gum disease, or periodontitis, can follow if the gingivitis is not addressed.
“The whole body is fighting against this bacteria,” Visser said. “The immune system is really provoked and alert and working really hard against these bacteria.”
This chronic inflammation becomes a vicious cycle: more swelling of the gums enlarges the gap between the teeth and gums, allowing more bacteria to enter, which can lead to inflammation of not only the gums but also the underlying bone. Continued unabated, the body will reject the tooth, causing loosening and eventual loss of the tooth.
This chronic inflammationcanspill from the mouth into the rest of the body. Gum disease is linked to an increase in pro-inflammatory molecules in the blood, Dioguardi said.
Chronic inflammation in the body can, in turn, lead to chronic neuroinflammation in the brain, which induces neurodegeneration and plays a key role in Alzheimer’s.
Oral health and dementia
Visser is conducting a longitudinal study collecting oral health data — X-rays of teeth and samples of bacteria — from several hundred patients with cognitive impairment to get more information about how their oral health affects their cognitive risk.
Already, “we saw some really severe cases of oral health problems which are missed by the doctors,” she said.
The challenge of untangling the relationships between our lifestyle, our teeth and our brains remains.“There are so many confounders, lifestyle, smoking, educational level diet,” Visser said. “So it’s really hard to do this research.”
Until more is known, researchers stress that oral hygiene remains one of the simplest and most important ways you can take care of yourself.
“Raising awareness among the population about the increased risk of Alzheimer’s associated with tooth loss and periodontitis can lead to heightened attention towards oral health,” Dioguardisaid in an email.
For better health — and possibly for a healthier brain — keep brushing.
Impact of Oral Health on Mental Health
Your oral and mental health are more closely connected than you might realize. Mental health disorders can lead to some coping habits, like smoking, that have a negative impact on oral health. Some people with mental health problems may also avoid or stop going to the dentist.
People with mental illnesses like anxiety and depression may engage in behaviors or have other problems caused by their illness that affect oral health, such as:
- Loss of appetite, which can lead to causes poor nutrition
- Eating or drinking too many sugary foods or beverages
- Dental anxiety — fear of visiting the dentist
- Low energy
- Difficulty performing daily tasks like brushing their teeth
- Pain
- Alcohol use problems or drug use
- Smoking
- Dry mouth
Poor nutrition. If you have anxiety, depression, or another mental illness, you might not feel like eating. You might also eat or drink too many sugary treats or beverages that make you feel better for a while but can cause tooth decay and cavities.
People with poor nutrition or eating disorders may have low levels of calcium. Loss of calcium can weaken the surface enamel of your teeth. Some eating disorders such as bulimia, in which the person vomits after eating, can damage the throat, teeth, and mouth. Bulimia can also lower the amount of saliva in the mouth, which can cause dry mouth and dental problems.
Burning mouth syndrome — a chronic, burning sensation on the tongue, the roof of the mouth, and the inside of the cheeks — can be a sign of poor nutrition, but it may also be caused by depression. Some people with depression may have good oral health and good nutrition but may have burning mouth syndrome.
Anxiety. Many people, including those without a mental health problem, have dental anxiety. If you have an anxiety disorder, you may avoid seeing a dentist regularly, which can lead to dental problems.
Low energy. Depression or other mental illnesses can make you feel tired and unmotivated. You may find it hard to perform basic tasks like brushing and flossing your teeth. You may also feel too tired to prepare meals, which may lead to poor nutrition.
Pain. Depression and anxiety can make you more sensitive to pain. This can make you fearful or anxious about going to the dentist.
Alcohol, smoking, and other drugs. You are more likely to drink alcohol if you have depression and anxiety. Over time, drinking too much alcohol can lead to gum disease and possibly cause oral cancer.
Dry mouth. Some medications used to treat mental illnesses, such as antidepressant drugs, may cause side effects like dry mouth. A dry mouth may increase your risk for gum disease.
Oral Health Preventive Care
Poor oral health can make your mental health worse. You might feel embarrassed about your teeth, or you may find it hard to eat or drink when you’re with other people. This can cause you to avoid being with people, which can affect your well-being.
Here are some steps you can take to keep your teeth and gums healthy:
- Brush your teeth twice a day with fluoride toothpaste
- Clean between your teeth with dental floss or an interdental brush twice a day
- Stop smoking
- Reduce alcohol use or stop drinking alcohol
- Cut back on sugary foods and drinks
- See your dentist regularly
- Eat a healthy, balanced diet
If your medication causes dry mouth, try xylitol mints. Xylitol is a natural sweetener that helps you make more saliva, and it can also help prevent plaque and cavities. Some helpful xylitol products include the following:
- Mints
- Gum
- Toothpaste
- Mouth spray
How to Manage Your Mental Health
You can take active steps to improve your mental health and well-being.
Exercise. Physical activity is not only good for your body but also good for your mental health. Exercise can increase your self-esteem, and it can change the chemicals in your brain to help improve your mood.
Connect with other people. Good relationships give you a sense of belonging, help you find support, and increase your self-worth. Here are some ways to build closer relationships:
- Have lunch with a work friend
- Go for a walk with a friend
- Talk with your kids or your partner at dinner, with your phones and your TV turned off
- Volunteer in your community
Practice Mindfulness. Take time to slow down and notice your feelings and the sounds, smells, and sights that surround you throughout the day. Training your mind to be in the present moment can help you feel calm and focused and can give you a sense of well-being.
See your doctor. If you’re struggling with your mental health, talk to your doctor. Your doctor may prescribe medications to treat your problem or may help you find a therapist.
Oral health and mental health are closely connected. Make sure that you visit your dentist regularly, and if you have concerns about your mental health, don’t delay discussing your problem with your doctor.
Sources
The Washington Post