A couple years ago my state, Washington, legalized pot.
It’s been a boon for tax revenue, for sure (almost $83 million in the first year). And the state reports that it has saved millions of dollars by freeing up law enforcement resources.
Judging from the lines in front of the pot stores (green crosses are everywhere!), pot is really popular here, across a wide range of ages.
But apart from its commercial success, and the fact that it’s given us more stoned drivers, the law concerns me because it seems to promote the idea that smoking pot is harmless to your health.
Two recently published reports show that pot has a negative effect on the brain.
In JAMA Internal Medicine I read about one study that followed over 5,000 men for close to 30 years. Those that currently used marijuana, or had in the past, were given cognitive function tests. The results?
Current use of marijuana was associated with worse verbal memory and processing speed; cumulative lifetime exposure was associated with worse performance in all 3 domains of cognitive function. After excluding current users and adjusting for potential confounders, cumulative lifetime exposure to marijuana remained significantly associated with worse verbal memory.
The authors suggest that more research is needed on the long-term effects of smoking pot, and more public education needs to be funded to teach young people about the risks associated with pot.
Related post from The Health Care Blog: Marijuana Know-Nothingism
But most the people I see buying pot are not young people—you have to be 21. And I know people in their 60s and 70s who are smoking pot. They used marijuana as teens and young adults, and now enjoy being able to buy it legally.
Another study in Neurology Times links pot, especially the more popular high-potency stuff (aka “skunk”) with damage to a particular part of the brain called the corpus callosum.
Overall, the investigators found that those individuals who used higher potency cannabis had more white matter lesions in their corpus callosum when compared to users of the less potent forms of cannabis. Daily use was also associated with a corresponding increase in white matter lesions.
Psychiatrists may…want to advise their patients who use recreational or medicinal cannabis about how much is too much, or whether any use is advisable.
Yikes. I’m worried enough about dementia without helping it along. And who wants lesions on their brain?
As drugs go (including alcohol), pot is not considered lethal. Unless you’re in a traffic accident, you probably won’t die from smoking pot.
But there is just not enough information yet about the long-term effects of pot use.
Another study has linked pot to heart problems, causing a cardiologist to comment:
The perception is that marijuana is a magical drug, that it’s totally safe, and we can use it in medical treatment. What we don’t know about are the negative effects, the potential harms.
I’m on the fence about whether legalizing pot was a good idea or not.
I know more research will be forth coming, especially as more states debate legalization.
At this time, however, no one can say with any certainty how much is too much, or how often is too often.
I would advise friends that if you smoke pot, use it in moderation, choose strains with lower THC levels, and please don’t drive stoned!