Severe Periodontal Disease linked to increased dementia risk
Gum disease, especially the kind that is irreversible and causes tooth loss, may be associated with mild cognitive impairment and dementia 20 years later. The study has been published in Neurology®, the medical journal of the American Academy of Neurology.
"We
looked at people's dental health over a 20-year period and found that people
with the most severe gum disease at the start of our study had about twice the
risk for mild cognitive impairment or dementia by the end," said study
author Ryan T. Demmer, Ph.D., M.P.H., of the University of Minnesota School of
Public Health in Minneapolis. "However, the good news was that people with
minimal tooth loss and mild gum disease were no more likely to develop thinking
problems or dementia than people with no dental problems."
The study involved 8,275 people with an average age of 63 who did not have
dementia at the start of the study. The participants were assessed for mild
cognitive impairment and dementia. Participants received a full periodontal
exam that included measuring gum probing depth, amount of bleeding and
recession.
Then
participants were put into groups based on the severity and extent of their gum
disease and number of lost teeth, with implants counting as lost teeth. At the
start of the study, 22% had no gum disease, 12% had mild gum disease, 12% had
severe gum inflammation, 8% had some tooth loss, 12% had disease in their
molars, 11% had severe tooth loss, 6% had severe gum disease, and 20% had no
teeth at all.
A total of 4,559 people was assessed at the end of the study, when they had
been followed for an average of 18 years.
Overall,
1,569 people developed dementia during the study, or 19%. This was the
equivalent of 11.8 cases per every 1,000 person-years. The study found that of
the people who had healthy gums and all their teeth at the start of the study,
264 out of 1,826, or 14%, developed dementia by the end of the study. For those
with mild gum disease, 623 out of 3,470, or 18%, developed dementia. For
participants with severe gum disease, 306 out of 1,368, or 22%, developed
dementia. And 376 out of 1,611, or 23%, developed dementia in the group that
had no teeth. This was equal to a rate of 16.9 cases per 1,000 person-years.
When looking at both mild cognitive impairment and dementia, the group with no
teeth had about twice the risk compared to participants with healthy gums and
all their teeth. People with intermediate or severe gum disease, but who still
had some teeth, had a 20% greater risk of developing mild cognitive impairment
or dementia compared to the healthy group. These risks were after researchers
accounted for other factors that could affect dementia risk, such as diabetes,
high cholesterol and smoking.
Good dental hygiene is a proven way to keep healthy teeth and gums throughout
your lifetime. Our study does not prove that an unhealthy mouth causes dementia
and only shows an association. Further study is needed to demonstrate the link
between microbes in your mouth and dementia, and to understand if treatment for
gum disease can prevent dementia," Demmer said.
A
limitation of the study is the fact that initial gum examinations were made
when the participants had an average age of 63, and it is possible that
cognitive decline might have been begun before the start of gum disease and
tooth loss.