Marijuana Linked to Early Gum Disease
Study Shows Heavy Pot Smokers Had the Most Gum Damage
WebMD News Archive
Feb. 5, 2008 -- Gum disease is widely considered a disease of aging, but
that may not be true for young adults who smoke marijuana on a regular basis.
Heavy pot use was found to be strongly associated with gum disease at age 32
in a study published in the Feb. 6 edition of The Journal of the American
After controlling for other risk factors for gum disease, including tobacco
use, the 32-year-old study participants who smoked the most marijuana were 60%
more likely to show evidence of gum disease than 32-year-olds who had never
Almost one in three people had some evidence of gum loss.
"We found that about a fifth of the participants actually had adult gum
disease in their mid-20s and by age 32 the number was just under a third,"
researcher W. Murray Thompson, PhD, tells WebMD. "It is clear that smoking -- whether it is tobacco or cannabis -- damages
Marijuana, Tobacco, and Gum Disease
The study included 903 young adults followed from age 3 as participants in a
larger, ongoing New Zealand comprehensive health trial. All were born at the
same hospital in Dunedin, New Zealand, between April 1972 and March 1973.
Study participants were asked about their use of marijuana at ages 18, 21,
26, and 32; dental examinations were conducted at ages 26 and 32.
About a third reported no exposure to marijuana, while slightly under half
reported some exposure, defined as smoking marijuana between one and 40 times
during the previous year.
The 20% of people who smoked more than this were considered heavy marijuana
Compared with people who smoked no pot at all, heavy marijuana users were
three times more likely to have at least one gum site with evidence of severe
gum disease and 60% more likely to show evidence of mild gum disease.
Infrequent marijuana users also had more evidence of gum disease than
nonusers, but not as much as frequent users.
Earlier data from the Dunedin trial showed cigarette smoking to be a strong
risk factor for gum disease in the study participants, who were then in their
mid-20s. This was confirmed in the latest findings from the trial, but no
interaction was seen between cigarette and marijuana smoking in terms of
predicting gum disease.
One good piece of news: Cigarette smokers who gave up the habit before they
reached their late 20s had no more evidence of gum disease by age 32 than
people who had never smoked, Thomson says.
"With the gums there is a constant fine balance between destruction and
repair," he says. "Smoking tips the balance toward destruction, and if
you don't smoke the balance is tipped back toward repair."
'Canary in the Coal Mine'
Thomson and colleagues conclude that smoking may prove to be the
"primary behavioral risk factor" for early gum disease.
In an editorial accompanying the study, University of Washington dental
professor Philippe Hujoel, PhD, writes that evidence of gum disease in young
smokers could also be considered the "canary in the coal mine" for
other lifestyle-related diseases like diabetes and heart disease.
Hujoel tells WebMD that since young people tend to visit dentists more than
doctors, dentists may be the first to recognize the early signs of an unhealthy
"The dental profession has an opportunity to detect the early clinical
signs of unhealthy lifestyles, including potential drug abuse, and could play a
role with physicians in addressing the challenges of reducing chronic
[lifestyle-related] disease," he writes.