Marijuana Smoke Can Alter DNA And Lead To Cancer

By Margarita Nahapetyan

Smoking the cannabis plant (also known as pot, marijuana and ganja), can damage DNA and increases the risk of developing cancer, discovered researchers from England and Sweden. The experts also claim that marijuana smoke can actually be more harmful for smokers, than tobacco smoke.

A principal author of the study, toxicology expert Dr. Raj Singh , from Leicester University's Cancer Biomarker Prevention Group, said that his research provided the first "convincing evidence" that cannabis could alter DNA and, therefore, allow cell mutation, which, in turn, increases the risk of developing the fatal disease. "There have been many studies on the toxicity of tobacco smoke," said Dr. Singh, and added that cannabis, in contrast, has not been studied so thouroughly.

The expert further explained that the plant is less combustible, when compared to tobacco, and is often mixed with tobacco for the purposes of use. Cannabis smoke contains 400 compounds including 60 cannabinoids. However, because of its lower combustibility it carries 50 per cent more carcinogenic polycyclic aromatic hydrocarbons, such as naphthalene, benzanthracene, and benzopyrene, compared to tobacco smoke. To put it in other words, because it is much more difficult to burn, it turns out that cannabis smoke contains more carcinogens than tobacco smoke.

During their researh, using a technique known as mass spectrometry, the scientists focused on acetaldehyde, a toxic substance that can be found in both tobacco and marijuana cigarettes. The results revealed that cannabis smoke causes significant damage to DNA, much in the same way tobacco does, which means that there is a big chance of developing cancer from cannabis use.

However, according to the researchers, marijuana may pose a higher risk of developing cancer because of the differences in smoking techniques between the two substances. When smoking marijuana, the users inhale more deeply, compared to cigarette smokers, which puts respiratory organs under bigger pressure. The smoking of 3 to 4 marijuana cigarettes per day is associated with the same degree of damage to bronchial mucus membranes as 20 or more tobacco cigarettes a day.

While these new findings without any doubt will be a big obstacle in the arguments for legalizing cannabis, we all understand that it cannot be the only reason to decline its legalization. It has been known for many years that smoking tobacco cigarettes may lead to lung cancer, but no one has ever thought to make it illegal. Expect epidemiological studies to follow this report as the experts attempt to trace the link between cancer and cannabis use in the general population.

The researchers who carried out this study, stated quite clearly in their report that "the data obtained from this study suggesting the DNA damaging potential of cannabis smoke highlight the need for the stringent regulation of the consumption of cannabis cigarettes, thus limiting the development of adverse health consequences such as cancer."

The research team has also included Jatinderpal Sandhu, Balvinder Kaur, Tina Juren, William P. Steward, Dan Segerback and Peter B. Farmer from the Cancer Biomarkers and Prevention Group, Department of Cancer Studies and Molecular Medicine and Karolinska Institute, Sweden.

The study is published in the journal Chemical Research in Toxicology.