Health Day

Pot smokers face many of the same health consequences that tobacco users do, such as an increased risk of heart disease, but until now, it wasn’t known that marijuana use could also destroy gum tissue.

In the Feb. 6 issue of the Journal of the American Medical Association, researchers reported that heavy marijuana users have as much as three times the risk of developing serious gum disease compared to those who haven’t smoked pot.

“We found in our study that long-term heavy [marijuana] smokers had a greater risk of gum disease by the time they reach their early 30s,” said study lead author W. Murray Thomson, a professor of dental epidemiology and public health at the Sir John Walsh Research Institute at the School of Dentistry in Dunedin, New Zealand.

“The gums in a person’s oral cavity before the age of 35 seem to be a pretty sensitive marker for adverse lifestyles,” said Philippe Hujoel, a professor in the department of Dental Public Health Sciences at the University of Washington School of Dentistry. Hujoel wrote an accompanying editorial in the same issue of the journal.

Marijuana is the most widely used illicit drug in the United States, according to the National Institute on Drug Abuse (NIDA). Smoked like tobacco, it has many similar ill health effects. Marijuana use has been associated with increases in the risk of heart disease, head and neck cancers, problems in the lungs and infection. Marijuana has also been associated with social behavior problems, according to NIDA.

For the study, Thomson and his colleagues used data from a group of 900 New Zealanders who have been followed from birth into their early 30s. The group members have been assessed 11 different times since they were 3 years old. The researchers began asking about marijuana use at age 18, and then again at 21, 26 and 32. Dental examinations were conducted at 26 and 32 years of age, according to the study.

Thomson acknowledged that it’s sometimes difficult to get people to accurately report illicit drug use. But, he’s confident in this case that the use of marijuana was honestly reported, because this group has been participating in this study for so long and knows that its answers will remain confidential.

The researchers identified three marijuana “exposure” groups: No exposure, 32.3 percent; some exposure, 47.4 percent; and high exposure, 20.2 percent.

After adjusting the data to account for tobacco use, gender and a lack of dental care, the researchers found that those in the high-use group had a 60 percent increased risk of early periodontal disease, a 3.1 times greater risk of more advanced gum disease, and a 2.2 times increased risk of losing a tooth due to gum disease, compared to those who didn’t use marijuana.

“We think that it is the same as with tobacco smoke: That is, the effect is not directly on the gums as smoke is inhaled. Instead, it acts through toxins being absorbed into the bloodstream via the lungs and then affecting the body’s ability to heal itself after bursts of destructive inflammation in the gums,” Thomson said.

The bottom line, he said, is “don’t smoke, whether it’s cannabis or tobacco — it’s not a rational thing to do, and it has far-reaching effects on your health.”

If you’re concerned about the health of your gums, Hujoel suggested that you avoid risk factors, such as smoking, and ask your dentist or periodontist what additional steps you can take to protect them. If you have early periodontal disease, he said that regular periodontal maintenance care is generally recommended, but there may be other treatments, depending on your individual periodontal health.

People of European and African ancestry have differences in gene expression levels that affect how they respond to certain kinds of drugs and fight off specific types of infections, says a new U.S. study.

Researchers studied 30 white families from Utah and 30 Yoruban families from Nigeria, and found significant variations in nearly 5 percent of the 9,156 genes they analyzed. The findings were published online in the American Journal of Human Genetics and are expected to be published in the March 7 print issue of the journal.

“Our primary interest is the genes that regulate how people respond to medicines, such as cancer chemotherapy,” senior study author Eileen Dolan, a professor of medicine at the University of Chicago, said in a prepared statement. “We want to understand why different populations experience different degrees of toxicity when taking certain drugs and learn how to predict who might be most at risk for drug side effects.”

In this study, Dolan and her colleagues found expected variations in immune system response to microbial invaders. Previous studies have shown that black Americans may be more susceptible than whites to infection by certain kinds of bacteria, such as the kind that cause periodontitis.

But they also made some unexpected findings of major differences in expression levels of genes involved in a communication system that governs basic cellular activities and coordinates cell actions.

“Population differences in gene expression have only recently begun to be investigated. We believe they play a significant role in susceptibility to disease and in regulating drug response. Our current research focuses on how these genetic and expression differences play a role in sensitivity to adverse effects associated with chemotherapy,” Dolan said.

Learning more about how a person’s genetics affects their response to drugs may help lead to improvements in treatment.

Your risk of developing tongue cancer increases if you have severe gum disease along with human papillomavirus (HPV), new research suggests.

Previous studies have found periodontitis, which destroys connective tissue and bone supporting the teeth, and HPV each pose increased risks of cancer in the head, neck or tongue. This new study, from researchers at the University at Buffalo School of Dental Medicine, shows the two may work in tandem.

In a study of 30 patients newly diagnosed with squamous cell carcinoma on the base of the tongue, 63 percent (19 patients) had tumors testing positive for a common type of HPV. In addition, 90 percent of the patients with HPV-positive tumors had periodontitis, and 79 percent of patients whose tumors showed no presence of HPV did not have periodontitis.

“Evidence of periodontitis-HPV synergy has important practical implications, because there is a safe treatment for periodontitis but no treatment for HPV infection,” Mine Tezal, an assistant professor in the dental school’s Department of Oral Diagnostic Sciences, said in a prepared statement. “If these results are confirmed by other studies, this has a tremendous relevance in predicting and intervening in the initiation and prognosis of HPV-related diseases, including head and neck cancers.”

Tezal, who is also a research scientist at Roswell Park Cancer Institute, is scheduled to present the finding Friday at the American Association of Dental Research annual meeting, in Dallas.

Most people contract HPV infection at least once in their lives, but one’s immune system often fights it off without incident.

“Persistence of HPV infection is the strongest risk factor for carcinogenesis,” Tezal said. “Thus, the identification of factors that influence the persistence of HPV infection is critical to facilitate efforts to prevent head and neck cancers. This study implicates that chronic inflammation and co-infection with oral bacteria may be significant factors in the natural history of HPV infection.”