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Examining the Relationship Between Tooth Loss and Dementia

April 01, 2019
Heidi Magyar, PsyD, ARNP

BOSTON, Mass.—After seeing her mother struggle with dementia, Heidi Magyar, PsyD, ARNP, vowed to learn everything she could about the disease—for her own sake, as well as for her family and her patients.

Dr. Magyar, a psychiatric nurse practitioner, became a research assistant in dementia studies at the University of South Florida. She learned there are nonmodifiable risk factors, but there are also many modifiable risk factors, such as diet, exercise, alcohol use, smoking, isolation and education level.

After making changes in her life to limit those risk factors, and working with her patients to have them do the same, she learned of newly identified modifiable risk factors: tooth loss and chewing dysfunction. Her husband, who is a dentist, had never heard of the connection, and neither had his colleagues, or her own coworkers.   

Dr. Magyar, a professor of psychology and nursing at California Southern University in Costa Mesa, wanted to know more and researched the connection. She presented some of her findings at re:Think, a series of TED-style talks given by innovative experts in the mental health field, at Elevate by Psych Congress.

Also at re:Think: A New Kind of Heart

According to her presentation, the average number of teeth at age 65 is 18.9 (a full set is 32 teeth), 27% of people at age 65 have no teeth, and 1 in 10 people at age 65 have dementia. The question, she said, is: Do dementia, tooth loss, and chewing dysfunction just happen to occur at the same time, or is there a cause and effect relationship?

There is a breakdown in blood circulation to the brain in all types of dementias, Dr. Magyar said, and tooth loss and chewing dysfunction reduce blood flow and cause other changes to the brain. For example, imaging studies show that chewing increases blood flow to the hippocampus, which is the first area of the brain affected by dementia, she said. The prefrontal cortex and cerebellum also rely on blood flow from chewing.

In addition, studies have shown changes in the structure of teeth or the force of the bite can cause significant changes in the body. In a rodent study, altering teeth by just fractions of millimeters showed effects on the hormone which corresponds with cortisol in humans, Dr. Magyar said. Those hormones are associated with spatial memory deficits, which could be  related to the navigational skills seen lacking in many dementia patients, she explained.

The relationship between chewing and dementia may also have to do with the consistency and texture of food, she said. Rodent studies have shown the expression of brain derived neurotrophic factor (BDNF) was reduced in mice receiving soft food, and the deficiency was reduced when a diet including hard food was resumed. BDNF protects cells against death and encourages cell growth.

A frequent attendee of Psych Congress, Dr. Magyar said she was honored to speak at re:Think and saw it as an exciting challenge. She hopes her presentation showed attendees that many steps can be taken to prevent dementia or delay its onset.

“I hope that practitioners will include asking about dental status when assessing older patients,” she said. “It is easy and can be included in an assessment right away and may make a difference.”

—Terri Airov

Reference

“Mastication, memory, and the mind: apples & oranges or cause & effect?” Presented at Elevate by Psych Congress: Boston, Massachusetts; March 10, 2019.

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