Does cannabis harm the lungs?
- Studies show no connection between marijuana smoking and lung cancer, even for heavy smokers
An older, but still very relevant study shows that smoking marijuana does not increase the chances of developing lung cancer. However, the same cannot be said for cannabis smokers who "enhance" their smoking sessions with a regular cigarette.
The study documented cases of "heavy" smokers. A heavy smoker profile included users who had smoked approximately 22,000 joints throughout their lifetime. The results surprised the scientists, who expected at least a partial increase in cancer chances for such cases.
"We know that cannabis smoke contains a certain proportion of carcinogens (substances that cause cancer) and it's possible that this number is similar to the number of carcinogens in cigarette smoke," says one of the researchers, Donald Tashkin from the University of California Medical School in Los Angeles (UCLA David Geffen School of Medicine). "It is therefore quite surprising that the results differ so much from regular smokers. Even among the biggest cannabis consumers, we found no connection between lung cancer and their extensive use of this substance."
The age of study participants was limited to people under 60, as there were not enough older individuals who had regularly used cannabis since their teenage years. "Most people who used cannabis during their youth are just now reaching an age where cancer onset could be observed."
Participants consisted of 611 patients with lung cancer and 601 additional patients with head or neck cancer. These patients were then compared with 1,040 other people from Los Angeles (not suffering from cancer), according to criteria such as age, gender, and place of residence.
All subjects were then asked about their use of marijuana, tobacco, alcohol, and other drugs. Additionally, the questionnaire covered dietary habits, type of employment, family history of lung cancer, and socioeconomic status.
The heaviest cannabis smokers were ultimately classified as a group of users who had consumed more than 22,000 joints. A moderately advanced group was defined as those with 11,000 to 22,000 joints.
Different consequences of cigarettes and joints
While cigarette smokers, whose usage reaches up to two packs daily, showed approximately a 20-fold increase in lung cancer risk, cannabis users showed no increase, even in the group of heaviest users.
Other studies examining cannabis smoke content found that compared to cigarette smoke, cannabis smoke may contain up to 50% more substances considered carcinogenic. Moreover, cannabis smokers tend to inhale smoke deeper into their lungs. So how is it possible that marijuana smokers have such a minimal chance of developing lung cancer?
Significance of THC
The answer to this question is not certain today, but researchers are betting on the importance of tetrahydrocannabinol, one of the psychoactive cannabinoids contained in cannabis, THC. "Studies of THC's effects on our body's cells demonstrate anti-carcinogenic properties of THC, which can program the death of genetically damaged cells or cut off their blood supply," says Professor Tashkin.
Professor of Molecular Biology from the University of Colorado, Robert Melamede, derives from this data that the carcinogenic properties of cannabis smoke are completely nullified by the beneficial, anti-carcinogenic effects of THC.
For comparison, the main active ingredient in cigarettes is nicotine - which demonstrably disrupts the self-defense function of lung system cells. As a result, it appears that nicotine acts completely opposite to THC.
And what do you think, our readers? Does medical cannabis use harm your lungs? Share your opinions and experiences in the comments section!