# What does marijuana really do to your body? **URL:** \ **Category:** Factual Questions\ **Created:** [October 9, 2004, 5:43pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383 "2004-10-09T17:43:46Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 10, 2004, 6:49pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/21 "2004-10-10T18:49:01Z")
How does marijuana smoking compare to tobacco smoking? Basically, we don’t know. We havent’ studied it long enough. There are a number of reasons for that. One, people who smoke a lot aren’t always forthcoming about it, and don’t get put into many quality studies. Two, those that do smoke a lot haven’t been followed for 30 or more years, and compared to their peers over the same length of time. Three, many who do smoke it regularly also smoke tobacco, so it’s hard to sort one effect from the other. Four, noone is funding a lot of research into the longterm lung effects of smoking marijuana. It’s not sexy, like the ciggy studies. So we have to extrapolate. We compare the smoke of marijuana to the smoke of tobacco. And overall we conclude, that the smoke from marijuana contains at least as much tar and carbon monoxide and other nasties as tobacco, if not a whole lot more. We also see from other studies that marijuana smokers tend to inhale deeper and hold the smoke in longer than tobacco smokers. Meanwhile tobacco smokers smoke a whole lot more of the time than marijuana smokers. So we give an edumacated guess: We’re pretty darn sure it can’t be very good for you, but we can’t give you much in the way of numbers or statistics. I have no qualms in telling my patients that the smoking is damaging their lungs in ways we can’t quantify, and they’d all be better off not smoking it. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 10, 2004, 6:52pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/22 "2004-10-10T18:52:50Z")
> [@alterego](#): > > I believe that most of the physical affects of smoking tobacco/marijuana can be avoided by using a vaporizer. Hearsay, but it makes sense. Use of water pipes with tobacco significantly increases the nicotine and carbon monoxide exposures. It is no cure-all for the problems associated with inhaling burning, corrosive gases. > **[VCU News](https://www.news.vcu.edu/)** > > VCU News is your destination for stories that show the impact of a top, urban public research university, and the people who make it great. ---
**Author:** ![Elvez](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@Elvez](https://boards.straightdope.com/u/Elvez)\ **Post date:** [October 11, 2004, 3:12am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/23 "2004-10-11T03:12:24Z")
This is from Michael Pollan’s _[The Botany of Desire: A Plant’s-Eye View of the World](http://www.amazon.com/exec/obidos/tg/detail/-/0375760393/103-5123655-4857467?v=glance)_ > [@](#): > > In the mid-1960’s, an Israeli neuroscientist named Raphael Mechoulam identified the chemical compound responsible for the psychoactive effects of [pot]: delta-9-tetrahydrocannabinol, or THC, a molecule with a structure unlike any found in nature before or since. > … > In 1988 Allyn Howlett, a researcher at the St. Louis University Medical School, discovered a specific receptor for THC in the brain – a type of nerve cell that THC binds to like a molecular key in a lock, causing it to activate. Receptor cells form part of a neuronal network; the brain systems involving dopamine, serotonin, and the endorphins are three such networks. When a cell in a network is activated by its chemical key, it responds by doing a varity of things: sending a chemical signal to other cells, switching a gene on or off, or becoming more or less active. Depending on the network involved, this process can trigger cognative, behavioral, or physical changes. Howlett’s discovery pointed to the existence of a new network in the brain. > The cannabinoid receptors Howlett found showed up in vast numbers all over the brain (as well as in the immune and reproductive systems), though they were clusterd in regions responsible for the mental processes that [pot] is known to alter: the cerebral cortex (the locus of higher-order thought), the hippocampus (memory), the basal ganglia (movement), and the amygdala (emotions). Curiously, the one neurological address where cannabinoid receptors _didn’t_ show up was in the brain stem, which regulates involuntary functions such as circulation and resp[iration. This might explain the remarkably low toxicity of cannibis and the fact that no one is known to have ever died from an overdose. > On the assumption that the human brain would not have evolved a special structure for the express purpose of getting itself high on [pot], researchers hypothesized that the brain must manufacture its own THC-like chemical for some as-yet-unknown purpose. … In 1992… Raphael Mechoulam found it: the brain’s own endogenous cannabinoid. He named it “anandamide,” from the Sanskrit word for “inner bliss.” > … > Following on their work, neuroscientists are now busy trying to figure out exactly how the cannabinoid network works – and why we should have one in the first place. > … > When I asked Howlett what the purpose of such a network might be, she began her answer by listing some of the various direct and indirect effects of cannibinoids: pain relief, loss of short-term memory, sedation, and mild cognative impairment. > “All of which is _exactly_ what Adam and Eve would want after being thrown out of Eden. You couldn’t design a more perfect drug for getting Eve through the pain of childbirth or helping Adam endure a live of physical toil.” She noted that cannabinoid receptors had been found in the uterus, of all places… Howlett speculated that the human cannabinoid system evolved to help us endure (and selectively forget) the routine slings and arrows of life “so that we can get up in th emorning and do it all over again.” It’s the brain’s own drug for coping with the human condition. ---
**Author:** ![D0pBOt](https://avatars.discourse-cdn.com/v4/letter/d/3ab097/32.png) [@D0pBOt](https://boards.straightdope.com/u/D0pBOt)\ **Post date:** [October 11, 2004, 5:26am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/24 "2004-10-11T05:26:45Z")
Smoking it carries the usual risks involved with inhaling burning substances. Tell him to bake with it rather (that’s bake like with an oven… first). 😃 mmmm, [cannabutter](http://www.drugs-plaza.com/marihuana_how_to_make_hash.htm#cannabutter)… ---
**Author:** ![PatriotX](https://avatars.discourse-cdn.com/v4/letter/p/c4cdca/32.png) [@PatriotX](https://boards.straightdope.com/u/PatriotX)\ **Post date:** [October 11, 2004, 5:58am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/25 "2004-10-11T05:58:01Z")
> [@Qadgop the Mercotan](#): > > Use of water pipes with tobacco significantly increases the nicotine and carbon monoxide exposures. It is no cure-all for the problems associated with inhaling burning, corrosive gases. > [http://www.vcu.edu/uns/Releases/2004/april/042604.html](http://www.vcu.edu/uns/Releases/2004/april/042604.html) I’m no expert, but I think that vaporizers heat the marijuana to the point where the oils evaporate, but not to the point where there’s combustion. So, it’s not exactly smoking it. ---
**Author:** ![Atticus\_Finch](https://avatars.discourse-cdn.com/v4/letter/a/ec9cab/32.png) [@Atticus\_Finch](https://boards.straightdope.com/u/Atticus_Finch)\ **Post date:** [October 11, 2004, 6:52am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/26 "2004-10-11T06:52:22Z")
A related question - Is the “six weeks” figure for the amount of time detectable residues of marijuana remain in your body true? Also, is it an urban myth or do marijuana residues remain for longer than usual in the testicles? ---
**Author:** ![Cerri](https://avatars.discourse-cdn.com/v4/letter/c/3bc359/32.png) [@Cerri](https://boards.straightdope.com/u/Cerri)\ **Post date:** [October 11, 2004, 7:08am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/27 "2004-10-11T07:08:40Z")
> [@Qadgop the Mercotan](#): > > Use of water pipes with tobacco significantly increases the nicotine and carbon monoxide exposures. It is no cure-all for the problems associated with inhaling burning, corrosive gases. > [http://www.vcu.edu/uns/Releases/2004/april/042604.html](http://www.vcu.edu/uns/Releases/2004/april/042604.html) A vaporizer, not a water bong. You’re still burning the marijuana with a water bong, you don’t burn the marijuana with a vaporizer. Whether or not the vaporizer produces _no_ carcinogens is a question I’m not positive of, but I do know that by not burning it to extract the THC, you’re definitely not producing the carcinogens you would if you burned it. [http://www.canorml.org/healthfacts/vaporizers.html](http://www.canorml.org/healthfacts/vaporizers.html) ---
**Author:** ![alterego](https://avatars.discourse-cdn.com/v4/letter/a/6bbea6/32.png) [@alterego](https://boards.straightdope.com/u/alterego)\ **Post date:** [October 11, 2004, 6:20pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/28 "2004-10-11T18:20:45Z")
Great link **Cerri**. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [October 11, 2004, 6:42pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/29 "2004-10-11T18:42:51Z")
> [@Atticus Finch](#): > > A related question - Is the “six weeks” figure for the amount of time detectable residues of marijuana remain in your body true? Also, is it an urban myth or do marijuana residues remain for longer than usual in the testicles? Case history (me): When my company began random testing I stopped smoking pot for over a year. Then one weekend I smoked a few joints with a friend. _Seven_ weeks later I got tested. I didn’t even worry about it, but sure as hell I tested positive. Four weeks after that (total of over three months) I was still testing positive, but at below policy levels. I know nothibg about the balls part of your question. Peace, mangeorge ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [October 11, 2004, 7:17pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/30 "2004-10-11T19:17:10Z")
> [@yabob](#): > > Not entirely bizarre. Paranoia or panic attacks happen in enough people for it to be noted in the literature. That would be me. If I smoke pot, I get panick attacks. By the way, it came out of the blues. I used to be a regular (as in every day) cannabis smoker without any problem and suddenly one day, I got my first panic attack. I was smoking a particularily strong cannabis in this instance, so maybe it’s part of the reason, but even a mild one would now have the same consequences. Also, a friend of mine who was a very very heavy cannabis smoker became psychotic (paranoid). But perhaps this could have been caused or aggravated by his intensive use of cannabis, and perhaps it’s totally unrelated. How could we know? ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [October 11, 2004, 7:20pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/31 "2004-10-11T19:20:59Z")
FTR, my uncle (who I rarely see) is dying from lung cancer. He never smoked cigs but has smoked pot for over 30 years now and continues to toke during treatment (not a blood relative, thank god). I do believe he’ll have part or all of his lung removed. Don’t know the frequency he smoked - he has 3 kids and one of those “normal family lives” so I don’t know when he really had the time or privacy to light up. But I’m sure he has been smoking quite regularly since he went a bit batty and moved to LA by himself to become a bodybuilder/actor… I will also say both his parents have passed away in the last 5 years from cancer. But who’s to say if that’s why he has lung cancer? His 5 older and younger siblings don’t smoke weed and they don’t have it. Anyway, there’s one story about getting cancer from smoking pot (presumeably) ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [October 11, 2004, 10:07pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/32 "2004-10-11T22:07:45Z")
Some interesting [facts](http://www.cancer.ca/ccs/internet/standard/0,3182,3172_367563_259538_langId-en,00.html); > [@](#): > > Smoking and lung cancer > It is estimated that smoking is responsible for 30% of all cancer deaths and is related to more than 85% of lung cancer cases. So 70% of cancer deaths and 15% of lung cancer are not related to smoking. My point is that although smoking is idiotic, having lung cancer certainly doesn’t prove one to be a smoker. BTW; I’ve read that while pot smokers are likely to light up cigarettes, they’re also very likely to let it burn up without actually smoking it. I used to do that. A lot. 😉 ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 11, 2004, 10:13pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/33 "2004-10-11T22:13:19Z")
> [@Cerri](#): > > A vaporizer, not a water bong. Ah. Gotcha. Just don’t assume it’s safe. We lack credible data about the long-term effects of these devices. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [October 11, 2004, 10:17pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/34 "2004-10-11T22:17:47Z")
Ok - I’d recommend this excellent website that can no doubt educate you as to the positives and negatives of the substance. Dr. Grinspoon is a Harvard Medical School faculty member, so this is not just an advocacy site, but rather an educational one. I think the OP should be able to find what s/he is looking for. And, if not, it’s still a grand place to visit and learn. xo C. \<[www.marijuana-uses.com](http://www.marijuana-uses.com)\> ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [October 12, 2004, 2:03am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/35 "2004-10-12T02:03:28Z")
> [@ninetypercent](#): > > most marijuana smokers consume around a quarter ounce of the plant in a week. that’s 7 grams. I’m sure some do, but _most_? Smoking a quarter a week would mean spending $300 a month on weed, and spending every waking moment stoned. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [October 12, 2004, 3:15am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/36 "2004-10-12T03:15:07Z")
I don’t think this is exactly what the OP was asking for (nor are many of the posts above, it would seem), but a factoid I’ve heard is that marijuana is safer than aspirin: people have died of aspirin overdoses, but there is no known lethal dose of marijuana. So, **flamingbananas** , it would seem the best course might not be trying to scare your friend, but dealing with him rationally, friend-to-friend. Ask why he’s using so much pot, and whether it might have some negative effects on his _life_ (since we haven’t conclusively found many physical problems it’s likely to cause). If you can’t point any out to him, or if he doesn’t think they’re problems, then MYOB. ---
**Author:** ![flamingbananas](https://avatars.discourse-cdn.com/v4/letter/f/f4b2a3/32.png) [@flamingbananas](https://boards.straightdope.com/u/flamingbananas)\ **Post date:** [October 12, 2004, 8:30pm UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/37 "2004-10-12T20:30:02Z")
> [@commasense](#): > > So, **flamingbananas** , it would seem the best course might not be trying to scare your friend, but dealing with him rationally, friend-to-friend. Ask why he’s using so much pot, and whether it might have some negative effects on his _life_ (since we haven’t conclusively found many physical problems it’s likely to cause). If you can’t point any out to him, or if he doesn’t think they’re problems, then MYOB. I’ve tried this. He says he is “just experimenting” but this has been going on longer and heavier then I would think expirementing would be going on for. He does it here, which not only makes me mad and points out his stupidity, but it makes my asthma bad. I’ve pointed this out to him and he said that he would stop smoking it here, but when I got home the other day I smelled it. I know I can scare him off it if I can show him one fact that really freaks him out. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [October 13, 2004, 12:18am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/38 "2004-10-13T00:18:26Z")
> [@flamingbananas](#): > > I know I can scare him off it if I can show him one fact that really freaks him out. I don’t think you’re going to find one. Marijuana isn’t really a scary drug. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [October 13, 2004, 1:05am UTC](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383/39 "2004-10-13T01:05:28Z")
> [@ninetypercent](#): > > most marijuana smokers consume around a quarter ounce of the plant in a week. that’s 7 grams. Good lord, Man! (Woman?) Maybe in Jamaica, but not 'round here. When I smoked my heaviest - stoned \*\*every night \*\* (though not during the day), a quarter would last me for three months! The heaviest smoker I know personally goes through about an eighth a week, and he \*\*is \*\* so sh\*tfaced he can’t hold a job. If “most marijuana smokers” are buying a quarter a week, they’re smoking up a lot of their friends, or smoking more than they need, 'cause you just don’t need to consume that much on your own! (This actually makes the rest of your points even more salient, as the quantity of marijuana smoked by the average user is even lower than your estimate, I’m sure.) The only physical effect of marijuana that you might be able to scare your friend with only works if s/he’s under 22. And no, I don’t have a cite for it, so I can’t be 100% sure that it’s true, but it was told to me by a health teacher that I really trusted. She was the only adult who actually gave us “The Straight Dope” on the list of drugs the school made her teach us about in high school. (The school wanted her to say, “Drugs are bad, don’t do them.” but she actually gave us pros and cons on each one.) According to her, marijuana will cause the body to coat the neurons (nerve cells) with a thin layer of lipids (fat.) This lipid layer is needed in small bits to help electricity jump through nerves faster, but when too much is built up (like through smoking lots of weed) it actually acts as an insulation, slowing down the electrical charges, and therefore slowing down reaction speed, thinking, etc. Plus, since the neurons in your brain grow until you’re around 22, and they can’t grow through the excess lipids, you can actually stunt your brain growth on a neurological level if you smoke lots of pot before your brain in done growing. Now, when you stop smoking pot, this lipid layer will gradually be reabsorbed into the body. No harm, no foul - except if you’ve been smoking during adolescence, when the neurons should have been growing. They simply won’t grow later to catch up. Net effect: you’re dumber than you otherwise would have been. Like I said, I have no cite for this theory. I don’t know if it’s horribly outdated or been proven wrong or what. But it did stop me from toking up until I was 22! (I have heard that “they” are doing research into using marijuana to rebuild the mylein sheathing (that lipid layer around each neuron) in ALS patients, so it does make sense to me.) [Previous page](https://boards.straightdope.com/t/what-does-marijuana-really-do-to-your-body/268383.md?page=1)