The researchers from New Zealand conducted an experiment studying the dental health of 903 people from Dunedin, from 1972 to 1973. The subjects were asked about their marijuana use at ages 18, 21, 26, and 32 years old.
Findings revealed that more than one-third of the test subjects developed gum disease by the age of 32, and that cannabis smoking was the cause.
Also, smoking marijuana for about 41 times per year, from the age of 18, resulted in a 36 percent chance of developing periodontal disease for people between 26 to 32 years old. The test subjects who were the heaviest marijuana smokers were determined 60 percent more likely to develop gum disease, compared to those who never smoked.
The scientists noted that the measured effects of cannabis smoking on gum health were independent of the effects of tobacco smoking, said Bloomberg.
Professor Murray Thomson of the University of Otago, the lead researcher, explained that the effects were not because of the contact of the smoke to the gums, but the toxins present in cannabis, as they were absorbed into the blood through the lungs. According to him, this resulted in a decrease in the body's ability to heal gum inflammations caused by bacteria.
"In the mouth, there is a fine balance between tissue destruction and tissue healing and the various toxins in the smoke disrupt that," said Thomson, as quoted by the BBC.
Co-researcher James Beck said that he would want to conduct a similar study, focusing only on people who smoked cannabis but not tobacco.
The study appears in the February 6 issue of Journal of the American Medical Association.
