Carole Fleck,
senior editor at the AARP Bulletin, asked
Bruce Pihlstrom, DDS, acting director of the Center
for Clinical Research at the National Institute of
Dental and Craniofacial Research (NIDCR), an arm of
the National Institutes of Health, about the
apparent association between oral health and general
health. September 2006
Q. Will you
explain the emerging evidence linking oral and
general health? Much of the research has focused on
gum disease and its possible effect on heart and
vascular conditions. Could gum infections lead to
other types of problems?
A. We don't know.
One theory is that when bacteria that cause gum
disease get into the bloodstream—and we know that
happens—they might cause inflammation in arteries or
vessels that supply blood to the heart or brain. The
inflammation could contribute to a buildup or
rupture of plaque in the blood vessels, which in
turn could block the blood supply to the heart or
brain. The result is a heart attack or stroke.
Another theory is that inflammatory chemicals,
called cytokines, produced in response to gum
infections might be released into the bloodstream,
where they might contribute to inflammation in blood
vessels or arteries. The inflammation, in turn,
could lead to blockage of the blood supply to the
heart or brain. It is important to point out these
are just theories, and we don't know if it actually
happens or not.
Q. Where does
the research stand in establishing this connection?
A. A number of
observational studies have looked for an association
between gum disease and cardiovascular disease. Some
have found that people with periodontal disease are
more likely to have cardiovascular problems, while
others have found no connection between gum disease
and cardiovascular disease. It is worth noting that
these kinds of studies cannot tell us whether an
observed association is causal—that is, whether
periodontal disease causes cardiovascular problems.
The bottom line question is, "If you prevent or
treat gum disease, will you lower the risk for heart
disease or stroke?" The answer is we don't know.
Research has also
shown an association between periodontal disease and
diabetes, which is not surprising given that
diabetes increases a person's susceptibility to
infection. And we know that infection can make it
harder for the body to regulate insulin. That raises
the question of whether treating periodontal disease
can bring down blood sugar levels in people with
diabetes.
Q. What needs
to be done next? Where will this research take us?
A. Clinical trials
are needed to determine if controlling periodontal
disease will reduce the risk or severity of other
diseases such as heart disease, stroke or diabetes.
The NIDCR is supporting early studies that will
determine if treating gum disease leads to better
blood sugar control for people with diabetes. It
will be much harder to determine if controlling
periodontal disease can prevent heart disease or
stroke. We need additional proof of a substantial
relationship between gum disease and cardiovascular
disease before proceeding to clinical trials. The
NIDCR is supporting studies to define the
relationship, but a conclusive answer is probably
years away, in part because the diseases share risk
factors. For example, smoking increases the risk for
both periodontal disease and cardiovascular disease,
so how much of an observed relationship between the
diseases is due to periodontal infection and how
much is due to smoking? It is difficult to design a
study that teases out the effects of gum disease
from those of smoking or other risk factors for
heart disease and stroke.
Q. What
should people do to protect their health?
A. They should
practice good oral hygiene—brush and floss
regularly—and have regular dental checkups. I do it
because I like having a healthy mouth that enables
me to chew comfortably, and teeth that feel and look
good. The bottom line is that people should take
care of their mouth for its own sake—to avoid tooth
loss and to maintain oral comfort and function.
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