Cannabis and your health
The debate on cannabis and its impact on health has been simmering for decades, and although various physical and mental effects have been associated with using the drug, only a handful of these claims has proved conclusive. TheSite.org weighs up the evidence.
In the first half of the 20th century, legal issues led to a great deal of propaganda. Cannabis had been made illegal in 1928 and opponents of the drug wanted people to know about its dangers. A famous piece of propaganda was the film Reefer Madness. The film follows a group of high school students whose marijuana misuse leads to catastrophic consequences, such as manslaughter, rape, and suicide. As the medical community learnt more about cannabis, more varied reports started to hit the headlines. Today, conflicting medical research continues to further baffle the situation. So what are the health implications of taking cannabis?
Short-term health effects
Cannabis affects different people in different ways depending on a number of factors. These include how much you take, what type of cannabis you take, how experienced you are in using the drug, and your own mental state. The immediate effects of cannabis are short term and can be identified easily:
- The good - users will normally experience a period of euphoric intoxication commonly called a 'high'. This is the desired outcome for most people who take the drug;
- The bad - many will suffer from short-term memory loss and will have a reduced attention span after taking cannabis;
- The ugly - the more undesired psychological effects of taking the drug can sometimes overwhelm smokers. Increased anxiety, paranoia, and panic attacks are some of the unwanted effects you may experience (this state is sometimes called a 'whitey', because the person's face will turn a ghostly pale colour).
Some people who take the drug have also reported being affected by longer-lasting psychological episodes involving hallucinations and delusions.
Long-term health effects
The alleged link between smoking cannabis and lung cancer has spawned a big debate in the medical world. Despite several reports, there has been no overwhelming proof of this link and a general conclusion has yet to be reached.
The main problem is the fact that most people who smoke cannabis do so in conjunction with tobacco, which is known to be carcinogenic. Cannabis smokers also hold the smoke in their lungs for much longer to obtain the maximum hit from the smoke, which could put them at greater risk to any pollutants in the smoke.
It has been claimed that Queen Victoria was prescribed cannabis to relieve period pain.
A 2007 study by researchers at the Medical Research institute of New Zealand found that a single cannabis joint may cause as much damage to the lungs as five cigarettes. The research involved a group of 339 volunteers aged 18 to 70 who were divided into four groups according to whether they smoked only cannabis, only tobacco, both, or were non-smokers. Each volunteer had lung function tests and x-ray scans of their chests to assess the level of damage to their lungs and airways.
A conflicting study published in 2006 by the University of California concluded that there was no link between smoking cannabis and lung cancer. A total of 611 lung cancer patients living in Los Angeles, and 601 patients with other cancers of the head and neck were compared with 1,040 people without cancer. All the participants were asked about their use of marijuana, tobacco, and alcohol, as well as other drugs, their diets, occupation, and their family history of lung cancer.
Cannabis and mental health
Cannabis use is often linked with the development of psychotic illnesses in later life. In July 2007 researchers from Bristol and Cardiff universities published research that claimed cannabis users are 40% more likely to suffer a psychotic illness than non-users. Critics of this research argue that if cannabis does cause mental illnesses then the number of people with mental health conditions would have increased dramatically over the past 30 years, whereas the proportion of people with schizophrenia has remained roughly the same. Read more in our article on cannabis and mental health.
Research into the effects of cannabis on fertility has also proved inconclusive. Tests on animals have shown that high doses of THC (the main psychoactive substance found in cannabis) lowers testosterone, impairs sperm production, and disrupts the ovulation cycle. However, there are contradictory reports which claim that fertility rates are not affected by cannabis use.
Cancer healing claims
Research by Harvard University suggests that THC may have cancer healing potential. In lab and mouse studies, THC cut lung tumour growth in half and helped prevent the cancer from spreading.
Cannabis for pain relief
Cannabis has been used for centuries for medicinal purposes. It has even been claimed that Queen Victoria was prescribed the drug to relieve period pain. A report by the House of Lords Science and Technology Committee found that cannabis was being used in Britain by people with multiple sclerosis, epilepsy, and M.E. as a method of pain relief.
Doctors in Britain are allowed to prescribe Nabilone (capsules containing THC) to patients suffering from nausea caused by chemotherapy. However, patients who take the drug in capsule form complain that they cannot control the amount that they take, which causes the undesired side effects of cannabis. Pharmaceutical companies have started developing THC aerosols and inhalers that don't damage the lungs. This would enable patients to control the amount of THC they take and reduce the side effects.
Written by Chris Denholm
Read the comment policy
Use our free question and answer service and speak to an expert!