Does Marijuana Kill Brain Cells?

4 Jul

This Is Your Brain on Drugs.. Any Questions?

Let’s start with the classics. Here something you might remember if you’re 30 and up.

And yes, dear egg chef, actually I do have a question.

“Does marijuana really kill brain cells?”

OH – questions like these bring me to back to my childhood.

I’m in elementary school. We had police officers come in and talk about drugs. It was called the DARE program – a clever acronym which stood for Drug Abuse, Resistance, Education. I honestly don’t remember too much about the actual class other than teasing the officer about gangster rap and asking him if he listened to NWA. (Yes, in retrospect, quite ballsy for a 4th grader. I’m probably more scared of cops now at age 30.) But I feel like that’s the kind of quaint easily remembered tidbits kids walk away with from a class like DARE.

It also brings up a vague memory of my stoned brother telling me – in all seriousness – that yes, smoking weed kills brain cells but do you know how many brain cells we have? Like a million. So it doesn’t make any difference. I nodded and left it like that. What did I care? I was in 6th grade and weed was just something Dr. Dre and Cypress Hill rapped about, as obscure to me as gang bangin’ and hustlin’ on the streets.

It’s funny now to see this question creep back up online. You can find people asking on drug forums and Yahoo Answers. So let’s see if we can possibly settle the question once and for.

First, let’s make sure we even know what we’re talking about though. If people are going to say pot destroys brain cells, let’s look at just what a brain cell is in the first.


Brain Cells, Neurons, and Weed..Oh My.

So what is a brain cell?

It’s actually a neuron. At least, that’s what wikipedia redirects you to if you try to go to their page on brain cells.

Side note: “Smoking Marijuana Kills Neurons” just doesn’t have the same punch in the gut, does it?

I actually understand a bit about how the brain works (well, no one really understands how the brain works, eh…) so let’s see if I try my hand at explaining this like so

  • Think of the brain as a giant communication network.
  • Little bits of information communicate along this network via something called synapses. They do it by pushing around electric bits and chemical bits.
  • These little bits of information ARE the neurons themselves. Or, as you wish, the brain cells.

So if someone makes the claim the marijuana kills brain cells, they are saying that marijuana destroys the neurons in your brain – this tiny little thingy that consists of a a cell body, dendrites, and an axon (whatever that means). And so the inference is that it effects ones ability to think because, well, you’re killing the messenger, quite literally, with all that green.

Is is true, though?

Is It true, Though?

One thing that should catch your eye about brain cells / neurons dying in adults is that once they’re dead, they’re basically dead. They don’t really come back for the most part. So if you’re doing something that actively kills them, that’s kinda freaky.

Also it turns out my brother was right about at least one thing: there are a shit ton of neurons in our brains. Like something in the order of 100 billion. If I’ve got my zeros right, that’s 100,000,000,000 brain cells. Nice.

So does weed kill these cells or not?

The results are…. inconclusive.

Shitty, huh? I was dying to tell you that it was all a bunch of bunk but I suppose I’ll be a good journalist and just report the facts. Here’s a look at the relevant scientific data from a couple different studies:

  • Those toking up 7 or more times a week weren’t as good at a math test or a verbal expression test compared to non-smokers.
  • Those toking up 7 or more times a week might not transfer new experiences and information as well as non-smokers into their long term memory.

But then the same data goes on to say there’s not enough evidence to show a direct relationship between marijuana and the results. As in, maybe whatever predisposes those people to smoking so much weed is actually the cause behind their math and memory ills. D’oh.

  • Oh, and there’s also this great study that had some poor monkeys forced to inhale the equivalent of almost half a dozen joints a day. There brains were just as good as their monkey comrades who weren’t getting high as hell all day long. So I guess we know for monkeys the answer to the question but still aren’t exactly sure what it means for us.

So I guess the moral of the story is this:

If you smoke every single day, you might not be doing the best thing for your brain. Maybe.

But killing neurons?

Who knows. The damn scientists can’t seem to figure it out one way or the other. But it does seem clear that the idea that when you light up you fry your brain is entirely an exaggeration. It did make a cool commercial though.

Please Comment!

Feel free to rant and rave about this pot and brain damage below. Oh, and if you can reference a study to make your point, even better!


16 Responses to “Does Marijuana Kill Brain Cells?”

  1. Chris July 6, 2011 at 5:32 pm #

    Dr. Mitch Earlywine cites studies that show that teenagers who start smoking pot at a young age (~12-14) showed a 5 point drop in I.Q. – even as they got older compared to non-tokers. Not sure if this is because of killed brain cells, but I’m sure no one thinks it’s a good idea for kids to use cannabis. Regarding adults, scientific evidence supports the view that moderate use by adults is no more harmful than moderate alcohol consumption.

  2. Ben July 6, 2011 at 10:49 pm #

    Very interesting Chris. (And good to see you here!) I googled this guy and see he does a lot of scientific research – and defense – of marijuana with NORML.

    I would say that – and this is just my opinion – moderate pot smoking is less harmful than moderate alcohol use.

  3. YourSextoy July 11, 2011 at 10:19 am #

    Even alcohol usage does not destroy neurons, the impact seen on IQ tests and other meters used to measure the brain’s ability to function results from the alcohol’s disruptive effect that disencourages the brain from maintaining the connections between individual cells and formed clusters of cells, called semantic networks. Why the brain looks smaller when the observed person has been consuming alcohol for prolonged periods of time is because the sizes of the neurons has decreased. The number of neurons has not, however, changed.

    Pot does not destroy neurons and the observable effects are probably caused by the endocannabinoid system not supporting proactive creation of new neurological connections.

    Sniffing butane kills brain cells. Blasting your head with an x-ray probably busts a couple too. But killing brain cells with natural compounds that evidently are not poisonous…? Ridiculous. Cannabinoids exist in our body all the time, not all the same that are in pot but some anyway. Chemically causing the destruction of a neuron requires some effort.

  4. G$$$ September 17, 2011 at 5:17 am #

    This one is tricky. I’ve heard Statistics showing that yes you do have billions of neurons and that they die every day just from being alive so there is really no way to measure if or how many are lost. I think it’s propaganda in it’s finest. And for the IQ part I believe it’s not the marijuana affecting it but the type of person that is generally drawn to usage. That being said I also have friends how used to smoke often and maintain a 4.0. There is really no way of knowing. I’m also wondering how I got here from searching calea zacatachichi? Hoping for a lucid one tonight!!

  5. Davaughn September 28, 2011 at 7:26 pm #

    I am 15 years old and I have been smoking marijuana for about a year now. My honest opinion is that marijuana does not affect how many brain cells(nuerons)have been lost. Im not any dumber than I was before I started smoking weed. Through life I learned that smoking weed is not the best thing to do just to have a good time. But it helps relieve the stress related things that goes on in my teenage life. Life just brightens up you know, and marijuana helps me keep a positve attitude. Just because you smoke at an early age does not mean that you’ll be a pot head when you get older. Thats nonsense if you put dedication to what you do and believe you’re goin to be a higher achiever means it can happen. I can’t type for long because im in school right now I just had to comment because this caught my eye I will be back again to say some more things on my mind. ;)

  6. Mikejlang October 14, 2011 at 5:29 pm #

    Is it really a shocker that druggies are averaging 5pts less in IQ than a non drug user? Your a lower brain functioning human if you choose to do drugs in the first place, so anyone that is into drugs will always score less because that is their role in life. There are exceptions, society does have smart drug users and there are idiotic nondrug users. But a majority of drug users are not bright, I believe people are born users and when the choice is presented they will use. And to the 15yr old stoner, you be a pothead for life dont fool yourself.

  7. 420 all day November 20, 2011 at 5:16 am #

    Mikejlang is wrong, the 15 year old is right. I’m 16 and I have been smoking for about 2 years now and my grades in school have Actually been getting better than they used to be so marijuana doesn’t affect brain cells. Also marijuana is not addictive so if you smoke as a teen, it doesn’t mean you will smoke when your older. It’s all just a matter of choice.

  8. Common Sense December 6, 2011 at 5:34 pm #

    Mikejlang: Your comment was jaded by your opinion and you didnt provide one single fact. Along with the last comment being uncalled for. One thing that has been continually oevrlooked is that Alchohol is in fact a toxin to the body, and tobacco has adverse affects to the body. Both of these have been continually proven, without a doubt.

  9. Soccer bro 1 January 28, 2012 at 7:32 am #

    I smoke and nothings changed. And Mikejlang your talking about marijuana users being dumb and yet you say… “you be a pothead for life..” if you’re going to talk about others intelligence, you might want to use proper grammar.

  10. Droden March 12, 2012 at 3:50 am #

    Soccer bro 1 – your post, criticizing Mikejlang’s grammar, has at least three grammatical errors of its own. You are not making a strong argument if you mean to say that smoking marijuana does not negatively impact one’s intelligence. You might want to use proper grammar yourself.

  11. ace March 14, 2012 at 6:09 am #

    smoke weed every two or once a month weeks and you be ok for the rest of you life

  12. jake April 13, 2012 at 3:11 am #

    the monkey test was not something to go off of. The monkeys were suffocated with smoke. they had a gas mask that pumped pure marijuana smoke with no oxygen into there lungs. the brain cells were only killed because they were suffocating not because of the marijuana smoke

  13. Laura May 23, 2012 at 5:17 pm #

    im a smoker but i didnt start till i was 19 but im here for my dad has PROGRESSIVE SUPERNUCLEAR PALSY FOUND OUT THAT HIS BRAIN CELLS DIE OFF IN LIKE 9 DIFF PARTS IN THE BRAIN!!! Dad been burning since he was like 12 i think and was a heavy drinker. he stop drinking 16 yrs now so thats one off him but there nothing doctors can do for the palsy so im tryn find out if it will hurt him if he keeps smoken out but only like 2 joints aday???? any help would love it email me lauramcdonald47@yahoo.com

  14. Pothead-ish September 13, 2012 at 9:27 am #

    Mikejlang: Mate are you high? no pun intended. I have got to disagree with you on all your points. I’ve got friends who have Masters Degress and Honors (in engineering even) and they smoke 24/7. I’ve not seen them sober for years. Its childish to think stoners/drugies are meant to stay dumb because thats what society expects. NAH! Im a less frequent pot header now but i love my weed and i love being determined and challenged and not sit on my beanbag with my lava lamp on and listening to sublime’s santeria day in and out (i got high for the first time and that track was playing and for once i realised what he was saying in the whole song, RIP Sublime). OUT

  15. Pretty_Wreck January 17, 2013 at 10:56 pm #

    A lot of these comments are hilariously biased. I have read many articles and several books about cannabis so I hope my opinion here is based in some fact. However I do not claim to be any sort of expert.

    Now, as for what I have seen, cannabis’s effects on my have been two-sided. I have experienced a long-term reduction in the anxiety that has plagued me since birth. Also, some studies that I didn’t bookmark mentioned that a big factor of how it effects the person individually depends on there IQ to start with.

    And it makes since that people with less fortunate socio-economic status would have a predisposition for a less enriched development. However this is subjective to each individual, but I am speaking for the whole in regards to experience likelihood. Thus, those who are exposed to family issues, hard drug addiction or alcohol addiction problems, family problems, money problems, or violence problems, seen in increased abundance in lower-tier economic families & areas, you are able to realize the reasons why less economically fortunate family’s are more likely to use any drug, really.

    And as we should all be aware of, stress is a known long-term cognitive declining agent. So lower income areas are more likely to raise less potentially successful individuals due to the effects of stress and life purpose seen by a more survivalistic attitude that has been forced upon them.

    With me personally, the reduction in stress was more crucial to my memory then the temporary effects that THC-9/11 can have. So until I did a lot, my memory and cognition was actually cleaner and more efficient.

    Now, I am not saying cannabis directly benefits you, but as a result of the stress reduction, my cognition improved despite the temporary negative effects that this lovely green flour produces.

    And for weeks to months after, your cognition is effected. With myself personally, I have experienced a long-term stress and anxiety reduction. But, it the high amount I have used has caused a temporary decline in my memory, but abstaining for 2-4 weeks reduces this negative effect.

    So overall, it is primarily how you handle it, our power of neuroplastisity is quire incredible =-)

    So feel free to light up brothers and sisters, and embrace your humanity.

Trackbacks and Pingbacks

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    [...] We should never take for granted the bits and bytes that make up the thoughts inside your heads. Does marijuana kill brain cells? Probably not, but in an act of irony we have learned also that brain cells keep growing through [...]

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