University of Leicester researchers say they have found “convincing evidence” that cannabis smoke damages DNA in ways that could potentially increase the risk of cancer. The scientists say they found clear indication that cannabis smoke damages DNA, under laboratory conditions, when they used a newly developed, highly sensitive liquid chromatography-tandem mass spectrometry method. Parts of the plant Cannabis sativa, also know of course as Marijuana, are commonly smoked as a recreational drug.

 

Cannabis has not been as well studied as tobacco smoke, which is known to contain 4,000 chemicals of which 60 are classed as carcinogens, the researchers say. Cannabis smoke contains 400 compounds including 60 cannabinoids, the researchers say. But because of its lower combustibility, Cannabis smoke contains 50 percent more carcinogenic polycyclic aromatic hydrocarbons including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke, says researcher Rajinder Singh.

 

“It is well known that toxic substances in tobacco smoke can damage DNA and increase the risk of lung and other cancers,” the researchers say. “Scientists were unsure though whether cannabis smoke would have the same effect. Our research has focused on the toxicity of acetaldehyde, which is present in both tobacco and cannabis.”

 

The researchers say that the ability of cannabis smoke to damage DNA has significant human health implications, especially as users tend to inhale more deeply than cigarette smokers. This increases respiratory burden, they say. “The smoking of three to four cannabis cigarettes a day is associated with the same degree of damage to bronchial mucus membranes as 20 or more tobacco cigarettes a day,” they say. “These results provide evidence for the DNA damaging potential of cannabis smoke.” They conclude that smoking cannabis cigarettes—also known as joints—may be detrimental to human health as they could possibly initiate cancer development.