Originally Posted By: Merkava_4
Cigarettes are far, FAR more deadly than marijuana will ever be.
That is a dubious statement at best.
"Cannabis smoke contains many of the same carcinogens as tobacco smoke, including greater concentrations of certain aromatic hydrocarbons such as benzopyrene, prompting fears that chronic marijuana inhalation may be a risk factor for tobacco-use related cancers. However, marijuana smoke also contains cannabinoids such as THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol), which are non-carcinogenic and demonstrate anti-cancer properties in vivo and in vitro. By contrast, nicotine promotes the development of cancer cells and their blood supply. In addition, cannabinoids stimulate other biological activities and responses that may mitigate the carcinogenic effects of smoke, such as down-regulating the inflammatory arm of the immune system that is responsible for producing potentially carcinogenic free radicals (unstable atoms that are believed to accelerate the progression of cancer).
Cannabis smoke – unlike tobacco smoke – has not been definitively linked to cancer in humans, including those cancers associated with tobacco use. However, certain cellular abnormalities in the lungs have been identified more frequently in long-term smokers of cannabis compared to non-smokers. Chronic exposure to cannabis smoke has also been associated with the development of pre-cancerous changes in bronchial and epithelium cells in similar rates to tobacco smokers. Cellular abnormalities were most present in individuals who smoked both tobacco and marijuana, implying that cannabis and tobacco smoke may have an additive adverse effect on airway tissue. The results suggest that long-term exposure to cannabis smoke, particularly when combined with tobacco smoking, is capable of damaging the bronchial system in ways that could one day lead to respiratory cancers. However, to date, no epidemiologic studies of cannabis-only smokers have yet to reveal such a finding. Larger, better-controlled studies are warranted.
Cannabis consumers who desire the rapid onset of action associated with inhalation but who are concerned about the potential harms of noxious smoke can dramatically cut down on their intake of carcinogenic compounds by engaging in vaporization rather than smoking. Cannabis vaporization limits respiratory toxins by heating cannabis to a temperature where cannabinoid vapors form (typically around 180-190 degrees Celsius), but below the point of combustion where noxious smoke and associated toxins (i.e., carcinogenic hydrocarbons) are produced (near 230 degrees Celsius). Because vaporization can deliver doses of cannabinoids while reducing the users intake of carcinogenic smoke, it is considered to be a preferred and likely safer method of cannabis administration than smoking marijuana cigarettes or inhaling from a water pipe. According to the findings of a recent clinical trial, use of the Volcano vaporizing device delivered set doses of THC to subjects in a reproducible manner while suppressing the intake of respiratory toxins.
"Our results show that with the Volcano, a safe and effective cannabinoid delivery system seems to be available to patients,"investigators at Leiden University's Institute of Biology (the Netherlands) concluded.
"The final pulmonal uptake of THC is comparable to the smoking of cannabis, while avoiding the respiratory disadvantages of smoking."
Head, Neck and Lung Cancers
While a handful of anecdotal reports and one small case-control study associate heavy marijuana use among younger adults with increased incidents of head, neck and lung cancers, no large scale population studies have replicated these results. Investigators at John Hopkins University in Baltimore reported that neither "lifetime use" nor "ever use" of cannabis were associated with head, neck or lung cancer in younger adults in a large, hospital-based case-control study of 164 oral cancer patients and 526 controls. Researchers concluded, "The balance of evidence from this, the largest case-control study addressing marijuana use and cancer to date, does not favor the idea that marijuana as commonly used in the community is a major causal factor for head, neck or lung cancer in young adults."
More recently, the results of a 2004 population-based case-control study of 407 individuals diagnosed with oral squamous cell carcinoma and 615 healthy controls found "no association" between cannabis use and incidents of oral cancer, regardless of how long, how much or how often individuals had used it. A second 2004 case-control study of 116 oral cancer patients and 207 matched controls also failed to identify any association between self-reported cannabis use and oral cancers in adults age 45 years old or younger, although only 10 percent of patients in the study identified themselves as heavy users of cannabis.
A 1997 retrospective cohort study examining the relationship of marijuana use to cancer incidence in 65,171 men and women 15 to 49 years of age in California found that cannabis use was not associated with increased risks of developing tobacco-use related cancers of the lung and upper aerodigestive tract, and in fact, no cases of lung cancer were identified among men and women who used marijuana but did not smoke tobacco. Critics charge that volunteers in the study were relatively young and that the follow up period was fairly short, arguing that "such a study could not have been expected to detect any relationship between marijuana and lung cancer if the lag period were comparable to that seen with tobacco," which typically occurs after at least 20 years of smoking cigarettes and/or among adults over age 60. The study’s author responds: "
n contrast to users of tobacco and alcohol, most cannabis users generally quit using cannabis relatively early in their adult lives. … Therefore, even diseases that might be related to long-term use of cannabis (e.g. lung cancer) are unlikely to have a sizeable public health impact because most people who try cannabis do not become long-term users."
Government reviews investigating a possible link between cannabis use and lung cancer have also failed to find a definitive causal connection between the two. A 1998 report by the British House of Lords Science and Technology Committee concluded, "There is as yet no epidemiological evidence for an increase risk of lung cancer" in cannabis smokers, though authors did concede that studies have revealed cellular changes in the airways of cannabis smokers that could potentially be pre-cancerous. An 18-month study by the US National Academy of Science Institute of Medicine also concluded, "There is no conclusive evidence that marijuana causes cancer in humans, including cancers generally related to tobacco use," but added that cellular studies and a handful of poorly controlled case studies suggest that cannabis smoke may be "an important risk factor" for the development of upper aerodigestive or lung cancers. A 2002 Canadian Senate review further commented that among the small number of case studies present in the literature: "[N]one compare the prevalence of cancer with a control group or evaluates the use of cannabis in a standardized way. Interpretation is also limited by the fact the patients smoked tobacco and drank alcohol."
http://norml.org/component/zoo/category/cannabis-smoke-and-cancer-assessing-the-risk
