Liberal Leader Justin Trudeau drew criticism from both the Conservatives and NDP after declaring his support for legalizing marijuana last week. Claiming that marijuana is “no worse” than smoking or drinking alcohol, Trudeau said many studies support his views. But medical professionals are divided on the issue.
Wayne Hindmarsh, a University of Toronto professor specializing in toxicology, said research still cannot answer many questions about marijuana. Dr. Pamela Squire, a Vancouver physician who specializes in pain treatment, agrees there’s debate in some areas of cannabinoid research, but says there is plenty of evidence, especially in pain management, that suggests benefits.
Hindmarsh and Squire gave a glimpse of what the medical community really knows about the effects of pot:
Benefits of marijuana:
Marijuana helps with pain — There is general agreement in the medical community that marijuana has positive effects in patients suffering from chronic pain. Squire said cannabis is particularly helpful in managing neuropathic pain, pain related to nerve injury. Smoking pot can relieve the pain HIV and AIDS patients experience, caused by drug side effects to the nervous system. In 2005, Health Canada approved a mouth spray drug made of tetrahydrocannabinol (THC) and cannabidiol (CBD) — two chemical compounds found in marijuana — that relieves pain in multiple sclerosis patients. “We know it is helpful in pain after trauma injuries, a bit in arthritis, fibromyalgia,” she said. The debate in this area is not whether marijuana helps , but how long it can be helpful. Hindmarsh said that he has reservations about the long-term effectiveness of marijuana because patients can build up a tolerance to the drug.
Appetite stimulant — No debate here. It’s widely known that smoking pot can lead to increased appetite, often referred to in pop culture as a “case of the munchies.” This can be helpful for patients who suffer from a loss of appetite due to an illness or side effects from medication.
Nausea and vomiting — Both Squire and Hindmarsh agree that cannabinoids can be helpful in reducing feelings of nausea. Marijuana compounds are the components of some anti-nausea drugs for cancer patients undergoing chemotherapy, but in that case, drugs are injested, not smoked.
It’s easy to kick the habit — Unlike alcohol, Squire says people suffer minimal withdrawal symptoms when they bring an end to chronic marijuana use. “Most people don’t get severe withdrawal symptoms when they stop marijuana suddenly,” she said. The most common symptoms experienced are irritability, or having difficulty sleeping in the weeks after quitting.”
Harmful effects of marijuana:
Cognitive function — The short-term effects of marijuana are well documented. “It can affect your reaction time, it can affect verbal fluency, working memory,” said Squire, adding that it “might slightly increase risks for accidents while driving.” Combined with alcohol, the drug becomes more dangerous, she said. “Alcohol plus marijuana is a bad combination and can make you even more impaired.”
How long pot stays in the body — It has been well established that marijuana use is different to alcohol in this respect, according to Hindmarsh. Alcohol stays in the body for a short period of time, he said, but cannabis can remain in the body for up to four weeks. For users who smoke every day, the cannabis is stored in fat components of the body.
Links to mental illness — Particularly in youth aged 11 to 17, marijuana can trigger schizophrenia in people who are genetically predisposed to the illness. “It can also trigger an acute psychosis that doesn’t necessarily turn into schizophrenia,” said Squire.
Wheezing and hacking — Chronic marijuana smokers can develop bronchitis, an inflammation of airways that give oxygen to the lungs accompanied with a buildup of mucous.
The unknowns:
There is also debate about the consistency of the effects of marijuana on relieving stress and anxiety.
“I think we all agree that it relaxes the individual,” said Hindmarsh. “There is substantial evidence that the plant can take the edge off stress and anxiety,” said Squire. There have also been studies into marijuana and post-traumatic stress disorder. “The problem with PTSD is every time you have a nightmare or flashback, it’s as if that flashback or nightmare helps to cement the memory in and it looks like marijuana interferes with that,” she said.
But Hindman says that reactions to the drug can vary from person to person. “Some people don’t get the relaxed effect,” he said. “They get totally uptight.”
The side effects of the smoking aspect of marijuana is still an unresolved debate. Squire said there is no evidence that chronic marijuana smoking leads to chronic obstructive pulmonary disease, a chronic lung disease linked to smoking cigarettes that makes it difficult to breathe. But in terms of lung cancer, the medical community has not reached a consensus.
“There are several lines of evidence for and against marijuana use and lung cancer,” she said.
Hindman agrees that not enough is known on the topic and said he thinks politicians may come to regret any decisions to legalize the drug.
“I think we are going to have the same problems as the widespread use of cigarettes and a lot of health-related problems that are going to cost us a lot of money in the health-care system that is already overburdened.”
The long-term effects of cannabis on the brain are also unclear, said Squire, but if they are present, they appear to be subtle, she said.
