According to a recent report issued by the British Lung Foundation (BLF), despite the fact that 90% of a surveyed population feels that cannabis is safer than tobacco, their study makes the startling claim that one cannabis joint is as carcinogenic as 20 tobacco cigarettes. Fortunately for medical marijuana users, this claim clearly contradicts earlier studies that have proven there are no correlations between cannabis smoking and cancer:
One such study, conducted by Donald Tashkin at UCLA’s School of Medicine in 2006, surprised researchers by revealing that even long-term, heavy marijuana users who smoked on average more than 20,000 joints in their lifetime, still had no greater chance of contracting any form of cancer than non-marijuana users. Adversely, chronic cigarette smokers were found to have a 20-fold increase in lung cancer risk, despite there being no increase in cancer risk for marijuana smokers. In fact, UCLA researchers were shocked to discover that many long-term marijuana users had a lower risk of cancer than individuals who did not smoke marijuana at all.
Oddly enough, another study published earlier this year by Professor Stefan Kertesz at the UAB Division of Preventive Medicine indicates that the lung-expanding effects of smoking marijuana are actually beneficial to lung air-flow rates and lung capacity. His report showed that even moderate-to-high use of marijuana (at least one joint per day for seven years consecutively) does not decrease lung volume or overall airflow rates. In addition, various studies have proven that THC is actually highly anticarcinogenic, and is capable of shrinking tumors and/or preventing the growth of tumors when injected into lab rats.
So, what is the logic behind the British Lung Foundation’s claims that marijuana smoke is more dangerous than tobacco smoke? Well, according to their researchers, the reason why marijuana smoke is so dangerous is because users tend to hold it in their lungs for long periods of time in an effort to absorb more THC. Thus, they’ve admitted that it is not the constituents of the smoke itself, but the fact that some marijuana smokers hold the smoke in for longer than tobacco smokers.
However, scientists have proven that holding marijuana smoke in your lungs for more than 3 seconds is not necessary, as most THC is absorbed into cannabinoid receptors upon impact. As a result, the practice of holding smoke in the lungs is becoming less common amongst modern marijuana smokers.
While it is true that holding smoke in your lungs is obviously worse than quickly inhaling/exhaling it, it is not fair to say that marijuana smoke is more dangerous than tobacco smoke simply because some people choose to hold it in longer. Furthermore, given the fact that the UCLA study involved thousands of chronic marijuana smokers (who undoubtedly held the smoke in their lungs during use), it seems safe to say that cannabis smoke is definitely not more dangerous than tobacco smoke, and to the contrary has been proven to be surprisingly lung expanding and anti-carcinogenic.
In conclusion, although marijuana smoke does contain more tar than tobacco smoke, the anticarcinogenic properties of THC seem to drastically reduce chronic users’ chance of contracting cancer, rather than increase it.