Exposing Marijuana Myths: A Review of the Scientific Evidence Introduction Since the 1920s, supporters of marijuana prohibition have exaggerated the drug's dangers. In different eras, different claims have gained prominence, but few have ever been abandoned. Indeed, many of the "reefer madness" tales that were used to generate support for early anti-marijuana laws continue to appear in government and media reports today. For a while in the 1970s, it seemed as if scientific inquiries were beginning to influence the government's marijuana policies. Following thorough reviews of the existing evidence by scholars 1 and official commissions, 2 criminal penalties for marijuana offenses were lessened and a number of states moved in the direction of decriminalization. 3 However, in response to lingering concerns about marijuana's potential toxicity, the government expanded its funding of scientific research, mostly through the newly-created National Institute on Drug Abuse (NIDA). Probably the most important studies of the 1970s were three large "field studies" in Greece, Costa Rica and Jamaica. These studies, which evaluated the impact of marijuana on users in their natural environments, were supplemented by clinical examinations and laboratory experiments oriented toward answering the questions about marijuana that continued to be debated in the scientific literature. The data from these studies, published in numerous books and scholarly journals, covered such matters as marijuana's effects on the brain, lungs, immune and reproductive systems, its impact on personality, development, and motivational states, and its addictive potential. 4 Although these studies did not answer all remaining questions about marijuana toxicity, they generally supported the idea that marijuana was a relatively safe drug窶馬ot totally free from potential harm, but unlikely to create serious harm for most individual users or society. In the years since, thousands of additional studies have been conducted, many of them funded by NIDA, and together they reaffirm marijuana's substantial margin of safety. Our review of that body of work reveals an occasional study indicating greater toxicity than previously thought. But in nearly all such cases, the methodologies were seriously flawed and the findings could not be replicated by other researchers. Especially since the 1980s, when the federal government's renewed war on cannabis began, both the funding of marijuana research and the dissemination of its findings have been highly politicized. Indeed, NIDA's role seems to have become one of service to the War on Drugs. Dozens of claims of toxicity appear in its documents, despite the existence of scores of scientific studies refuting their validity. At the same time, studies that fail to find serious toxicity are ignored. In the following pages, we review the scientific evidence surrounding the most prominent of the anti-marijuana claims.
Exposing Marijuana Myths: A Review of the Scientific Evidence 3. Marijuana Is A Drug Without Therapeutic Value
Proposals to make marijuana legally available as a medicine are countered with claims that safer, more effective drugs are available, including a synthetic version of delta-9-THC, marijuana's primary active ingredient.
The Facts For thousands of years, throughout the world, people have used marijuana to treat a variety of medical conditions. 10 Today, in the United States, such use is prohibited. Although 36 states have passed legislation to allow marijuana's use as a medicine, federal law preempts their making marijuana legally available to patients. A number of studies have shown that marijuana is effective in reducing nausea and vomiting, 11 lowering intraocular pressure associated with glaucoma, 12 and decreasing muscle spasm and spasticity. 13 Today, many people use marijuana for these and other medical purposes, despite its illegal status. 14 People undergoing cancer chemotherapy have found smoked marijuana to be an effective anti-nauseant - often more effective than available pharmaceutical medications. 15 Indeed, 44 % of oncologists responding to a questionnaire said they had recommended marijuana to their cancer patients; others said they would recommend it if it were legal. 16 Marijuana is also smoked by thousands of AIDS patients to treat the nausea and vomiting associated with both the disease and AZT drug therapy. Because it stimulates appetite, marijuana also counters HIV-related "wasting," allowing AIDS patients to gain weight and prolong their lives. In 1986, a synthetic delta-9-THC capsule (Marinol) was marketed in the United States and labeled for use as an anti-emetic. Despite some utility, this product has serious drawbacks' including its cost. For example, a patient taking three five-milligram capsules a day would spend over $5,000 to use Marinol for one year. In comparison to the natural, smokeable product Marinol also has some pharmacological shortcomings. 17 Because THC delivered in oral capsules enters the bloodstream slowly, it yields lower scrum concentrations per dose. Oral THC circulates in the body longer at effective concentrations, and more of it is metabolized to an active compound; thus, it more frequently yields unpleasant psychoactive effects. In patients suffering from nausea, the swallowing of capsules may itself provoke vomiting. In short, the smoking of crude marijuana is more efficient in delivering THC and, in some cases, it may be more effective. The continuing illegality of medical marijuana is based more on political than scientific considerations. Although during the 1970s the government supported exploration into marijuana's therapeutic potential, 18 its role has become one of blocking new research l9 and opposing any change in marijuana's legal status. 20
Exposing Marijuana Myths: A Review of the Scientific Evidence 4. Marijuana Causes Lung Disease It is frequently claimed that marijuana smoke contains such high concentrations of irritants that marijuana users' risk of developing lung disease is equal to or greater than that of tobacco users.
Except for their psychoactive ingredients, marijuana and tobacco smoke are nearly identical. 21 Because most marijuana smokers inhale more deeply and hold the smoke in their lungs, more dangerous material may be consumed per cigarette. However, it is the total volume of irritant inhalationâ€”not the amount in each cigaretteâ€”that matters. Most tobacco smokers consume more than 10 cigarettes per day and some consume 40 or more. Regular marijuana smokers seldom consume more than three to five cigarettes per day and most consume far fewer. Thus, the amount of irritant material inhaled almost never approaches that of tobacco users. Frequent marijuana smokers experience adverse respiratory symptoms from smoking, including chronic cough, chronic phlegm, and wheezing. However, the only prospective clinical study shows no increased risk of crippling pulmonary disease (chronic bronchitis and emphysema). Since 1982, UCLA researchers have evaluated pulmonary function and bronchial cell characteristics in marijuana-only smokers, tobacco-only smokers, smokers of both, and non-smokers. Although they have found changes in marijuana-only smokers, the changes are much less pronounced than those found in tobacco smokers. The nature of the marijuana-induced changes were also different, occurring primarily in the lung's large airways - not the small peripheral airways affected by tobacco smoke. Since it is small-airway inflammation that causes chronic bronchitis and emphysema, marijuana smokers may not develop these diseases. 22 In an epidemiological survey, approximately 1200 subjects gave information on smoking and pulmonary function at two-year intervals. A large percentage of the subjects underwent pulmonary function testing. Although a small group who reported previous marijuana smoking had significant pulmonary abnormalities, current marijuana smokers had no significant reduction in any pulmonary functions. 23 There are no epidemiological or aggregate clinical data suggesting that marijuana-only smokers develop lung cancer. However, since some bronchial cell changes appear to be precancerous, an increased risk of cancer among frequent marijuana smokers is possible. 24 Since the pulmonary risks associated with marijuana are related to smoking, the danger is eliminated with other routes of administration. For committed smokers, pulmonary risk might be reduced with higher-potency products, which produce desired psychoactive effects with less inhalation of irritants. Smokers could also be encouraged to abandon deep inhalation and breath-holding, which increase drug delivery only slightly. Finally, pulmonary risk might be reduced if marijuana were smoked in water pipes rather than cigarettes. 25
Exposing Marijuana Myths: A Review of the Scientific Evidence 8. Marijuana Causes Brain Damage Critics state that marijuana has been shown to damage brain cells and that this damage, in turn, causes memory loss, cognitive impairment, and difficulties in learning.
The Facts The original basis of this claim was a report that, upon postmortem examinations, structural changes in several brain regions were found in two rhesus monkeys exposed to THC. 51 Because these changes primarily involved the hippocampus, a cortical brain region known to play an important role in learning and memory, this finding suggested possible negative consequences for human marijuana users. Additional studies, employing rodents, reported similar brain changes.
However, to achieve these results, massive doses of THC—up to 200 times the psychoactive dose in humans—had to be given . In fact, studies employing 100 times the human dose have failed to reveal any damage. 52 In the most recently published study, rhesus monkeys were exposed through face-mask inhalation to the smoke equivalent of four to five joints per day for one year. When sacrificed seven months later, there was no observed alteration of hippocampal architecture, cell size, cell number, or synaptic configuration. The authors conclude: "While behavioral and neuroendocrinal effects are observed during marijuana smoke exposure in the monkey, residual neuropathological and neurochemical effects of marijuana exposure were not observed seven months after the year-long marijuana smoke regimen." 53 Thus, 20 years after the first report of brain damage in two marijuana-exposed monkeys, the claim of damage to brain cells has been effectively disproven. No postmortem examinations of the brains of human marijuana users have ever been conducted. However, numerous studies have explored marijuana effect on brain-related cognitive functions. Many employ an experimental design—in which subjects are given marijuana in a laboratory setting, and then compared to controls on a variety of measures involving attention, learning and memory. In a number of studies, no significant differences were detected. 54 In fact, there is substantial research demonstrating that that marijuana intoxication does not impair the retrieval of information learned previously. 55 However, there is evidence that marijuana, particularly in high doses, may interfere with users' ability to transfer new information into longterm memory. 56 While there is general agreement that, while under the influence of marijuana, learning is less efficient, 57 there is no evidence that marijuana users—even longterm users—suffer permanent impairment. Indeed, numerous studies comparing chronic marijuana users with non-user controls have found no significant differences in learning, memory recall or other cognitive functions. 58
What is marijuana? Marijuana (grass, pot, weed) is the common name for a crude drug made from the plant Cannabis sativa. The main mind-altering (psychoactive) ingredient in marijuana is THC (delta-9tetrahydrocannabinol), but more than 400 other chemicals also are in the plant. A marijuana "joint" (cigarette) is made from the dried particles of the plant. The amount of THC in the marijuana determines how strong its effects will be. The type of plant, the weather, the soil, the time of harvest, and other factors determine the strength of marijuana. The strength of today's marijuana is as much as ten times greater than the marijuana used in the early 1970s. This more potent marijuana increases physical and mental effects and the possibility of health problems for the user. Hashish, or hash, is made by taking the resin from the leaves and flowers of the marijuana plant and pressing it into cakes or slabs. Hash is usually stronger than crude marijuana and may contain five to ten times as much THC. Pure THC is almost never available, except for research. Substances sold as THC on the street often turn out to be something else, such as PCP. What are some of the immediate effects of smoking marijuana? Some immediate physical effects of marijuana include a faster heartbeat and pulse rate, bloodshot eyes, and a dry mouth and throat. No scientific evidence indicates that marijuana improves hearing, eyesight, and skin sensitivity. Studies of marijuana's mental effects show that the drug can impair or reduce short-term memory, alter sense of time, and reduce ability to do things which require concentration, swift reactions, and coordination, such as driving a car or operating machinery.
Are there any other adverse reactions to marijuana? A common bad reaction to marijuana is the "acute panic anxiety reaction." People describe this reaction as an extreme fear of "losing control," which causes panic. The symptoms usually disappear in a few hours. What about psychological dependence on marijuana? Long-term regular users of marijuana may become psychologically dependent. They may have a hard time limiting their use, they may need more of the drug to get the same effect, and they may develop problems with their jobs and personal relationships. The drug can become the most important aspect of their lives. What are the dangers for young people? One major concern about marijuana is its possible effects on young people as they grow up. Research shows that the earlier people start using drugs, the more likely they are to go on to experiment with other drugs. In addition, when young people start using marijuana regularly, they often lose interest and are not motivated to do their schoolwork. The effects of marijuana can interfere with learning by impairing thinking, reading comprehension, and verbal and mathematical skills. Research shows that students do not remember what they have learned when they are "high". How does marijuana affect driving ability? Driving experiments show that marijuana affects a wide range of skills needed for safe driving -thinking and reflexes are slowed, making it hard for drivers to respond to sudden, unexpected events. Also, a driver's ability to "track" (stay in lane) through curves, to brake quickly, and to maintain speed and the proper distance between cars is affected. Research shows that these skills are impaired for at least 4-6 hours after smoking a single marijuana cigarette, long after the "high" is gone. If a person drinks alcohol, along with using marijuana, the risk of an accident greatly increases. Marijuana presents a definite danger on the road. Does marijuana affect the human reproductive system? Some research studies suggest that the use of marijuana during pregnancy may result in premature babies and in low birth weights. Studies of men and women may have a temporary loss of fertility. These findings suggest that marijuana may be especially harmful during adolescence, a period of rapid physical and sexual development. How does marijuana affect the heart? Marijuana use increases the heart rate as much as 50 percent, depending on the amount of THC. It can cause chest pain in people who have a poor blood supply to the heart - and it produces these effects more rapidly than tobacco smoke does. How does marijuana affect the lungs? Scientists believe that marijuana can be especially harmful to the lungs because users often inhale the unfiltered smoke deeply and hold it in their lungs as long as possible. Therefore, the smoke is in contact with lung tissues for long periods of time, which irritates the lungs and damages the way they work. Marijuana smoke contains some of the same ingredients in tobacco smoke that can cause emphysema and cancer. In addition, many marijuana users also smoke cigarettes; the combined effects of smoking these two substances creates an increased health risk. Can marijuana cause cancer? Marijuana smoke has been found to contain more cancer-causing agents than is found in tobacco smoke. Examination of human lung tissue that had been exposed to marijuana smoke over a long period of time in a laboratory showed cellular changes called metaplasia that are considered precancerous. In laboratory test, the tars from marijuana smoke have produced tumors when
applied to animal skin. These studies suggest that it is likely that marijuana may cause cancer if used for a number of years. How are people usually introduced to marijuana? Many young people are introduced to marijuana by their peers - usually acquaintances, friends, sisters, and brothers. People often try drugs such as marijuana because they feel pressured by peers to be part of the group. Children must be taught how to say no to peer pressure to try drugs. Parents can get involved by becoming informed about marijuana and by talking to their children about drug use. What is marijuana "burnout"? "Burnout" is a term first used by marijuana smokers themselves to describe the effect of prolonged use. Young people who smoke marijuana heavily over long periods of time can become dull, slow moving, and inattentive. These "burned-out" users are sometimes so unaware of their surroundings that they do not respond when friends speak to them, and they do not realize they have a problem. How long do chemicals from marijuana stay in the body after the drug is smoked? When marijuana is smoked, THC, its active ingredient, is absorbed by most tissues and organs in the body; however, it is primarily found in fat tissues. The body, in its attempt to rid itself of the foreign chemical, chemically transforms the THC into metabolites. Urine tests can detect THC metabolites for up to a week after people have smoked marijuana. Tests involving radioactively labeled THC have traced these metabolites in animals for up to a month. Source: National Institute on Drug Abuse, 1984. Annual deaths related to firearms in the United States: 29,000. Annual deaths related to prescription drugs: 32,000. Annual deaths related to alcohol: 85,000. Related to tobacco: 435,000. Marijuana? 0. Not a single case of death ever recorded in the United States, or even the world has been attributed to the use of marijuana. But there must be a reason for it’s prohibition and criminalization, correct? One thing that most people believe is that marijuana kills brain cells, which is in fact, a myth. “The original basis of this claim was a report that, upon postmortem examinations, structural changes in several brain regions were found in two rhesus monkeys exposed to THC. Because these changes primarily involved the hippocampus, a cortical brain region known to play an important role in learning and memory, this finding suggested possible negative consequences for human marijuana users.” “In the most recently published study, rhesus monkeys were exposed through face-mask inhalation to the smoke equivalent of four to five joints per day for one year. When sacrificed seven months later, there was no observed alteration of hippocampal architecture, cell size, cell number, or synaptic configuration”
Although it may not have deaths related to it, it must have some unhealthy attributes to it though, right? Again, wrong. “Tetrahydrocannabinol is a very safe drug. Laboratory animals (rats, mice, dogs, monkeys) can tolerate doses of up to 1,000 mg/kg (milligrams per kilogram). This would be equivalent to a 70 kg person swallowing 70 grams of the drug — about 5,000 times more than is required to produce a high. Despite the widespread illicit use of cannabis there are very few if any instances of people dying from an overdose. In Britain, official government statistics listed five deaths from cannabis in the period 19931995 but on closer examination these proved to have been deaths due to inhalation of vomit that could not be directly attributed to cannabis (House of Lords Report, 1998). By comparison with other commonly used recreational drugs these statistics are impressive.”
It seems you’re running out of questions. I’ll help you out though, it isn’t addictive, especially compared to legally distributable drugs such as alcohol, caffeine, nicotine, and other prescription drugs. However, it can be considered habitual, meaning if you smoke everyday for a year and you stop smoking, you will notice a difference. If you smoke a cigarette everyday, though, you will feel an immense amount of withdrawal. Another question to ask is, “what about the gateway theory?”. That is to say, once you try marijuana, you’ll want to try other hard drugs as well. The only proof of this is because of the prohibition of marijuana, that crack dealers happen to sell marijuana on the side or vice versa. This exposure makes it seem like it’d be okay to try it as well. However, there is only 1 cocaine user for ever 104 marijuana users and less than 1 heroin user for the same amount of marijuana users which is less than .96%. Not even 1%.
However if you compare two cities, such as Amsterdam and San Francisco (one where it is legal and one where it wasn’t at the time of recording) you can see that in Amsterdam it has a prodigious amount less than San Fransisco in the amount of cocaine, crack, amphetamines, ecstasy, and opiate usage. So if this plant is worth more ounce-per-ounce than gold, isn’t addictive, harmful, or a gateway then why is it still illegal? One might claim that it may be because government officials realize if they come out and say that marijuana isn’t harmful for you then they would be considered a liar. This only leaves the average citizen to take their stance on what is right. But why would they? All it does is make you think and cures or stabilizes several illnesses. Oh, I forgot to mention that. Many organizations have favorable positions (e.g., unimpeded research) on medical marijuana. These groups include: The Institute of Medicine, The American Cancer Society; American Medical Association; American Nurses Association; Australian Commonwealth Department of Human Services and Health; California Medical Association; Federation of American Scientists; Florida Medical Association; and the National Academy of Sciences. [xerocint.blogspot.com] ------------------------------------------------------------------"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."
Published on Apr 8, 2011
Published on Apr 8, 2011
3. Marijuana Is A Drug Without Therapeutic Value Introduction Proposals to make marijuana legally available as a medicine are countered with...