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Marijuana and Health

Some people argue that marijuana should be illegal because it poses health risks. This claim is not logically sound. Health considerations provide arguments to avoid excessive use of marijuana, but ultimately each individual should be allowed the personal freedom to decide whether or not to use marijuana.

  • Marijuana only poses health risks to people who choose to use it.
    As is the case with other potentially harmful substances, such as unhealthy foods, individuals should be able to weigh the risks for themselves. Think of it this way: numerous studies have shown that foods with a lot of cholesterol and fat are unhealthy. Should we outlaw bacon? That would be going too far. Instead, we should make sure to educate everyone about the dangers of a high-fat, high-cholesterol diet, but recognize that people should be free to make their own decisions about eating bacon. The same logic applies to marijuana.

  • The health risks associated with Marijuana are often misunderstood or exaggerated. The best recent scientific research shows that marijuana is much less harmful than prohobitionists say it is. The truth is that marijuana's health effects are complex and cannot be simply labelled good or bad.
    • Heavy Marijuana Use Doesn't Damage Brain (from WebMD, July 2003). A recent survey of research found that long term marijuana use did not have a significant effect on cognitive abilities. The report was published in the July 2003 Journal of the International Neuropsychological Society.
    • Study Finds No Cancer-Marijuana Connection (from Washington Post, May 2006). A recent study of the effects of long-term marijuana use found that "smoking marijuana, even regularly and heavily, does not lead to lung cancer." This study, the largest of its kind, was funded by the National Institute on Drug Abuse. The same study found that heavy tobacco use greatly increased the chance of lung cancer.
    • Marijuana Can Make Depression Better or Worse, Depending on Dosage (from CTV, October 2007). Researchers at McGill University studied the effects of THC on users suffering from depression (THC is the primary psychoactive component of marijuana). The study found that moderate doses of THC had an antidepressant effect, but that heavy doses of THC could make a patient's depression worse. This finding should serve as a reminder for those who would oversimplify the legalization debate by asserting that all use of marijuana is harmful (or beneficial). The truth is not one-sided.

  • Because marijuana is illegal, it cannot be controlled or regulated to protect health
    (Funny, don't they call it a controlled substance?). Because marijuana is not regulated, there are no safeguards against contamination by pesticides, herbicides, and other toxic chemicals. In this sense, it is actually the fact that marijuana is illegal that causes the health danger. If marijuana were legal, steps could be taken to reduce the health risks associated with its use by avoiding contamination.
    • Time Magazine reported in 1978 that numerous samples of marijuana imported to the United States from Mexico were contaminated with paraquat, a chemical herbicide capable of causing severe lung damage or death. It turned out that the paraquat had been sprayed on drug crops in Mexico as part of a U.S.-sponsored eradication program. The paraquat was not easily detected by consumers, and of course there was no regulatory inspection of imported marijuana to check for such contamination. While the spraying did not prevent the marijuana crops from being harvested or sold to American consumers, the contamination substantially increased the danger of consuming those crops. There is clearly something wrong with a drug policy by which the government, while supposedly protecting citizens from a drug, succeeds only in making the drug more harmful. (Of course there are additional health risks and ethical concerns raised by a policy of spraying harmful chemicals on areas inhabited by poor farmers.)
    • Contamination by Fungus Poses a Health Risk to Marijuana Users (from the Colorado Association of Property & Evidence Technicians). According to Judy O’Brien of the Westminster, Colorado Police Department, a fungus known as Aspergillus can grow on marijuana plants, especially if the crop is not properly harvested and dried. Inhaling the spores of Aspergillus can cause an allergic reaction and lung damage. O'Brien notes that Aspergillus contamination can be easily detected. However, under the present system of prohibition, marijuana consumers are on their own to detect and avoid the fungus. (This ChestJournal article, published by the American College of Chest Physicians, notes that Aspergillus exposure can be fatal to those with compromised immune systems.)

  • Marijuana can be used as medicine.
    There is an abundance of anecdotal evidence, as well as some scientific research, indicating that marijuana can be effective as a treatment for some illnesses. Benefits of marijuana can include appetite stimulation for cancer and AIDS patients, and general pain relief. Yet our government consistently stands in the way of research and testing of marijuana as medicine. Visit our Medicinal Use page for more information.



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