A new study suggests that smoking marijuana for decades can result in gum disease and tooth loss. However, connections to other health problems, including those typically associated with tobacco use, were not found.
The study analyzed approximately 1,000 people who used pot and/or tobacco in New Zealand. The results revealed that those who smoked pot for 20 years did not experience any notable health problems except for gum disease.
"Unlike tobacco smoking, cannabis smoking is associated with few physical health problems in midlife, with the exception of periodontal disease," said Madeline Meier of Arizona State University and lead author of the study.
In addition to examining gum health, Meier and her team also looked at lung function, risk factors for heart disease and diabetes and systemic inflammation, which can be a sign of trauma or infection.
The team still doesn't known exactly why marijuana is associated with poor dental health.
"Our analyses show that this association was not explained by tobacco smoking, alcohol abuse or less tooth brushing and flossing," Meier said.
Furthermore, the team can't prove definitively that marijuana causes gum disease, although she advises that "physicians should convey to patients that their cannabis use puts them at risk for tooth loss."
Despite the fact that the study only points to dental health as a risk of marijuana use, Meier doesn't want the study to mislead people into thinking that smoking marijuana has no negative impacts on human health.
"We don't want people to think, 'Hey, marijuana can't hurt me,' because research based on this same sample of New Zealanders has shown that marijuana use is associated with increased risk of psychotic illness, IQ decline, and downward socioeconomic mobility," she said.
The team also didn't examine participants long enough to determine the long-term effects of marijuana, including diseases that develop later on in life such as cancer.
"What we're seeing is that cannabis may be harmful in some respects, but possibly not in every way," said Avshalom Caspi of Duke University and co-author of the study. "We need to recognize that heavy recreational cannabis use does have some adverse consequences, but overall damage to physical health is not apparent in this study."
The findings were published in the June 1 issue of JAMA Psychiatry.
