Study: Marijuana Doesn't Affect Physical Health, Except For Gums
By Steve Elliott
Chronic marijuana use has about the same impact on health as not flossing, according to an extensive new study.
A research team led by Madeline H. Meier of Arizona State University tracked the cannabis habits of 1,037 New Zealanders all the way from birth to middle age, to see exactly what effects marijuana has on common measures of physical health, reports Christopher Ingraham at The Washington Post. Those measures included lung function, systemic inflammation, cholesterol levels, blood pressure, body weight, blood sugar, and dental health.
After controlling for other factors known to affect health -- especially tobacco use and socioeconomic status -- cannabis use had no negative effect on any measure of health, except for dental health. People who smoked more marijuana had a higher incidence of gum disease.
Even after controlling for dental hygiene, such as likelihood to brush and floss, the relationship between marijuana use and poor dental health persisted.
In some areas -- and this doesn't surprise many of us, at all -- cannabis use was associated with better health outcomes. "Findings showed that cannabis use was associated with slightly better metabolic health (smaller waist circumference, lower body mass index, better lipid profiles, and improved glucose control)," the study concluded.
"In general, our findings showed that cannabis use over 20 years was unrelated to health problems in early midlife," the study, published in the journal JAMA Psychiatry, found. "Across several domains of health (periodontal health, lung function, systemic inflammation, and metabolic health), clear evidence of an adverse association with cannabis use was apparent for only one domain, namely, periodontal health."
The findings were in stark contrast to the effects of tobacco use over a similar period of time.
“We can see the physical health effects of tobacco smoking in this study, but we don’t see similar effects for cannabis smoking,” said Meier, an assistant professor of psychology at Arizona State University who conducted the study with colleagues at Duke University, King’s College in the UK and the University of Otago in New Zealand, reports Duke Today.
"By comparison, tobacco use was associated with worse periodontal health, lung function, systemic inflammation, high-density lipoprotein cholesterol levels, triglyceride levels, and glucose levels in early midlife, as well as health decline from ages 26 to 38 years," the study found. Despite overblown concerns from some anti-marijuana groups such as the ironically named "Smart Approaches to Marijuana," about legal weed being "the next Big Tobacco," marijuana's toll on physical health appears to be far smaller.
"The general lack of association between persistent cannabis use and poor physical health may be surprising," Meier and her colleagues wrote. But, for some of us, they aren't surprising at all.
Meier's research is the first study that has used longitudinal data, tracing the health of individuals from birth, in the early 1970s, to age 38. Many other studies on the physical health impacts of cannabis relied on observations at a single point in time, which is less reliable for tracking lifelong effects.
Study co-author Avshalom Caspi, the Edward M. Arnett professor of psychology and neuroscience at Duke University, appeared to be struggling to find "something wrong" with cannabis, despite the findings, and was unintentionally humorous in so doing. “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,” he admitted.
“What we’re seeing is that cannabis may be harmful in some respects, but possibly not in every way,” Caspi managed.
But the bottom line is, the only impact shown to human health was to dental health.
“Physicians should certainly explain to their patients that long-term marijuana use can put them at risk for losing some teeth,” said Terrie Moffitt, the Nannerl O. Keohane University Professor of psychology and neuroscience at Duke and co-director of the Dunedin Multidisciplinary Health and Development Study, from which these data were gathered.
"Sucking smoke into your mouth, throat and lungs cannot be healthy," said dentist Dr. Rhonda Savage of Uptown Dental in Gig Harbor, Washington. "This is my opinion, as a health care provider. I apologize if I’m offending you. My concern isn't the issue of ethics, legality or right to use marijuana."
Photo: Uptown Dental