Heavy Marijuana Use Linked To Gum Disease, Study Shows

Periodontal disease is one of the most common chronic diseases in adults, with inflammation that can extend deep into the dental tissues, causing loss of supporting connective tissue and possible loss of teeth. Tobacco smoking is recognized as the primary behavioral risk factor for the condition, and it is thought cannabis smoking may have a similar effect, according to background information in the article.

In a group of more than 900 New Zealanders, smoking cannabis more than 40 times a year since age 18 was found to be responsible for more than one-third of the new cases of periodontal disease between ages 26 and 32, according to a new study. "Heavy cannabis use has been linked to greater risks of developing respiratory disease and some psychiatric conditions," said Terrie Moffit, a Duke University professor of psychology and neuroscience who participated in the study. "Gum disease should be added to that list of known hazards."

The study was led by W. Murray Thomson of the school of dentistry at The University of Otago, New Zealand, who measured gum recession at three sites on each tooth at ages 26 and again at 32. The study subjects are part of a longitudinal health and development study that has been tracking nearly 1,000 people born in Dunedin, New Zealand, in 1972 and 1973.

The link between gum disease and marijuana use emerged from a statistical analysis that controlled for gender, dental care, socio-economic status and how clean or dirty the teeth were. Most of the self-identified heavy marijuana users also were tobacco-users, but that factor was controlled statistically. The researchers also were able to focus on study participants who were not tobacco-users, and they still found a link between marijuana use and gum disease.

The precise physiology of smoke's effect on the gums is still not understood, but the team believes it interferes with immune function, inflammatory response and peripheral blood flow in the gums.

Journal reference: JAMA. 2008;299[5]:525-531

In addition to Moffit and Thomson, the study included Richie Poulton, David Welch and Robert Hancox of the Dunedin School of Medicine; Jonathan Broadbent of Otago's Dental School; James Beck of the Dental School at the University of North Carolina at Chapel Hill; and Avshalom Caspi of Duke University. Support came from the U.S. National Institutes of Health, the UK Medical Research Council and the Health Research Council of New Zealand.