Chronic pot use is as bad for your health as not flossing!

June 2, 2016 8:36 AM

A new study from Arizona State University that followed over a thousand New Zealanders from birth to 38 years of age has found that people who smoked marijuana had no worse health than people that didn't. Except that the pot smokers suffered from gum disease at a higher rate than the general public. So, make that hygienist appointment today!
posted by Pablo MacWilliams (41 comments total)

“Physicians should certainly explain to their patients that long-term marijuana use can put them at risk for losing some teeth”

I keep telling you guys to stop buying your shit from Mitch, he's a fucking lunatic
posted by griphus at 8:39 AM on June 2, 2016 [12 favorites]

Personally, I'd blame the Doritos.
posted by sexyrobot at 8:39 AM on June 2, 2016 [1 favorite]

Dude, flossing is too complicated for me even when I'm sober. I've never tried while high, but I imagine it would be like launching the goddamn Space Shuttle.
posted by escape from the potato planet at 8:44 AM on June 2, 2016 [14 favorites]

That was my first thought sexyrobot.

I also thought the quote "We don’t want people to think, ‘Hey, marijuana can’t hurt me,’ because other studies on this same sample of New Zealanders have shown that marijuana use is associated with increased risk of psychotic illness, IQ decline and downward socioeconomic mobility,” Meier said."

Yeah, when you throw someone in prison for 7 years for growing a plant, I bet they're going to have some mental health issues and they're gonna get more poor because they're the equivalent of a felon. Not quite sure how it works in NZ, but I'm sure its harder to get a job after you've been in prison, much like other parts of the world.
posted by furnace.heart at 8:49 AM on June 2, 2016 [7 favorites]

Dude, flossing is too complicated for me even when I'm sober. I've never tried while high, but I imagine it would be like launching the goddamn Space Shuttle.

I still don't floss often enough, but I would never do it at all without floss picks. Are they wasteful? Yes. Are they better than the alternative of never flossing because I can't figure out how? Also yes.

I bet flossing would feel really good while high, actually.
posted by uncleozzy at 8:53 AM on June 2, 2016 [7 favorites]

This pisses me off because I got gum disease without the buzz.
posted by srboisvert at 8:54 AM on June 2, 2016 [9 favorites]

Buy yourself some floss picks and keep 'em with you. After awhile you'll start to find the sensation of food debris in your mouth intolerable. I myself can't maneuver my hands around my mouth sufficiently to use just loose floss, but the picks are a godsend.
posted by Pope Guilty at 8:59 AM on June 2, 2016 [5 favorites]

It's not a counterpoint so much as a *The More You Know*, but Cannabinoid Hyperemesis Syndrome is no joke, let me tell you.
posted by hopeless romantique at 9:12 AM on June 2, 2016

My first reaction was- how did they find any New Zealanders that didn't smoke marijuana? The sample group size was 1037, and of that 675 or 65% had smoked. A bit less than the 100% I was expecting. In the US it is around 44%
posted by bhnyc at 9:16 AM on June 2, 2016 [1 favorite]

After awhile you'll start to find the sensation of food debris in your mouth intolerable.

But flossing isn't really about removing the kind of food debris you would actually notice. It's about plaque.
posted by dersins at 9:18 AM on June 2, 2016 [2 favorites]

The interesting thing about marijuana consumption in a place where it's now legal (Washington state) is that smoking to consume it seems to be less and less popular. I will be interested to see a study conducted here on the correlation between cannabis use and periodontal disease. heck, maybe i'll conduct the study myself....
posted by OHenryPacey at 9:21 AM on June 2, 2016 [1 favorite]

if you're going to use floss picks though, for the love of god, don't be gross about it. The number of those things I see on the sidewalk, what are you people even doing?
posted by Hoopo at 9:21 AM on June 2, 2016 [15 favorites]

In general I believe the findings of this study to be accurate, so I'm not actually questioning the findings. If you'd asked me an hour ago if I expected 38 year old who smoke pot (recreationally) to be as healthy as those who smoke tobacco, I' would have said yes. (Obviously people who smoke it medically are probably less healthy). In fact, I would guess the pot smokers to be more healthy. But I have some methods questions:

1. Note that there are no "non-smokers" in this study. The "non-smokers" referred to are actually "non-cannabis smokers". Everyone smokes tobacco. So the finding is that they're no less healthy than smokers who only smoke something else, not than non-smokers. So it's hardly true that this means it doesn't harm you. It just means it doesn't harm you anymore than something that is well-known to harm you. "No worse than cigarettes" is a pretty low bar for not doing harm.

2. There are no propensity scores used here. Given that people are not randomly assigned to smoke pot, it seems like there could be some selection effects here. e.g. Speaking for myself, I've always found the idea of smoking anything kind of revolting (who wants to breath smoke? I wouldn't even stand in the smoke of a campfire). But at one point in my life if the opportunity had presented itself, I might have tried an edible. The opportunity never presented itself at that time in my life. Since then I've had a complicated medical history, so if the opportunity presented itself now, I just wouldn't want to add yet another thing for my body to deal with so I wouldn't. There are all sorts of reasons why one's health might affect the likelihood of using pot, in both directions, without propensity scores, it's difficult to know what's really going on here if anything.

3. These people are only 38. If there are serious risks associated with regular pot smoking (and i bet there is at least this one) ti's going to be lung cancer. I can believe it might not be as risky as tobacco which is full of all sorts of other chemical crap, but look, inhaling smoke, even from your barbecue, is bad for your lungs. So let's wait another 30 years on this sample, before running out to declare smoking a risk free activity.

4. The measures of health are "We obtained laboratory measures of physical health (periodontal health, lung function, systemic inflammation, and metabolic health), as well as self-reported physical health, at ages 26 and 38 years." So no actual list of illnesses their sample has had. If pot smoking is associated with any specific illness this study wouldn't show it.

So while I believe pot isn't likely to be worse for you than any other drug we consider to be relatively low risk and smoking pot no worse than any other kind of smoke exposure, I wouldn't be so quick to conclude that this study shows that.
posted by If only I had a penguin... at 9:30 AM on June 2, 2016 [9 favorites]

The study authors were totally going to get to all of that, If only I had a penguin...
posted by clawsoon at 9:33 AM on June 2, 2016 [2 favorites]

But flossing isn't really about removing the kind of food debris you would actually notice. It's about plaque.

Given some of the stuff I dig out after a meal, I consider that a bonus.
posted by Pope Guilty at 9:41 AM on June 2, 2016

Electric toothbrush twice a day, floss couple of times a week and a few spliffs a night - every visit to the dentist ends with - you have perfect gums, keep it up!

Now I don't mention my spliff intake but if dentist is happy with my routine so am I!
posted by twistedonion at 9:42 AM on June 2, 2016 [1 favorite]

1. Note that there are no "non-smokers" in this study. The "non-smokers" referred to are actually "non-cannabis smokers". Everyone smokes tobacco.

Perhaps you have access to more information about this study than what is in the article, but I cannot see that this article makes that at all clear. Paragraphs 3 & 4, in particular, appear to be drawing a distinction between the health of tobacco users and that of non-tobacco users, which, to me at least, implies that there are indeed non-tobacco users included in the study:

Tobacco users in the study, which appears online the week of June 1 in JAMA Psychiatry, were found to have gum disease as well as reduced lung function, systemic inflammation and indicators of poorer metabolic health.

“We can see the physical health effects of tobacco smoking in this study, but we don’t see similar effects for cannabis smoking,” said Madeline Meier, an assistant professor of psychology at Arizona State University who conducted the study with colleagues at Duke University, King’s College in the UK and the University of Otago in New Zealand.

posted by dersins at 9:45 AM on June 2, 2016 [3 favorites]

You're right, dersins. I was going from the study abstract . My mistake came from the article title which says it's comparing cannabis and tobacco smokers and a mis-reading of I can't figure out what (I swear I "saw" in the abstract that they were all smokers, but now I can't find what I would have misunderstood to mean that). In fact, they are not all smokers: "The 1037 study participants were 51.6% male (n = 535). Of these, 484 had ever used tobacco daily and 675 had ever used cannabis." Unclear how many did both or neither. I had a look at the tables, but it's not clear to me (maybe someone else can read them more clearly than I can), if comparisons are to tobacco users as the title implies or to non-smokers.
posted by If only I had a penguin... at 9:59 AM on June 2, 2016 [1 favorite]

inhaling smoke, even from your barbecue, is bad for your lungs.

You're right, of course – but ingesting cannabis via smoking is on the decline. Vaporizers and edibles are very much the new normal in many circles.
posted by escape from the potato planet at 10:10 AM on June 2, 2016 [1 favorite]

(kinda) related: Colorado Stoner PSA.
posted by emjaybee at 10:51 AM on June 2, 2016

Given some of the stuff I dig out after a meal, I consider that a bonus.

I DIDN'T NEED TO KNOW THAT hahahahaha (but yeah that shit *is* gross huh?)
posted by Annika Cicada at 11:12 AM on June 2, 2016 [1 favorite]

uncleozzy: "I bet flossing would feel really good while high, actually."

Have you ever really just flossed your gums? I mean, really flossed them?
posted by chavenet at 11:41 AM on June 2, 2016 [6 favorites]

After awhile you'll start to find the sensation of food debris in your mouth intolerable.

But flossing isn't really about removing the kind of food debris you would actually notice. It's about plaque.


While the latter is certainly true that doesn't mean that the former can't act as a strong motivator.
posted by Hairy Lobster at 11:42 AM on June 2, 2016 [1 favorite]

Yes, smoking anything is bad - but what about vaping your marijuana? Colorado residents need to know. With all of the states with legal rec or MMJ it seems there must be many willing participants for studies.
posted by fieldtrip at 11:58 AM on June 2, 2016

But not flossing IS supposed to be pretty bad for your health. It causes heart disease. Look it up.
posted by serena15221 at 12:12 PM on June 2, 2016 [1 favorite]

inhaling smoke, even from your barbecue, is bad for your lungs.

You're right, of course – but ingesting cannabis via smoking is on the decline. Vaporizers and edibles are very much the new normal in many circles.

The study shows the pot smokers do not have any increase in lung disease!
posted by latkes at 1:03 PM on June 2, 2016

The study didn't measure lung disease, it measured lung function (presumably something like lung capacity? It doesn't actually say). Also, I aim still unclear on who they are comparing the pot smokers' lung function to given that the article title says "Comparison of Persistent Cannabis vs Tobacco Users"

Anyway, these people are only 38. Things like lung cancer, emphysema, etc., might not show up for another couple of decades. Don't confuse "could not discard the null" (i.e. found no evidence of increase lung disease (or in this case lung function), with "supported the null" (i.e. found that there is no increase in lung disease/lung function). They are not the same thing, statistically/methodologically.
posted by If only I had a penguin... at 1:20 PM on June 2, 2016 [3 favorites]

Anyway, these people are only 38. Things like lung cancer, emphysema, etc., might not show up for another couple of decades.

Or at all. We're talking about a massive difference in volume-of-stuff-smoked here.

There's what, a gram of tobacco in a cigarette? That means if you smoke a pack a day, you've smoked like 16 pounds of tobacco over the course of a year. (Which, ew gross. I really need to quit that shit.)

I know some pretty heavy weed smokers but I'm pretty sure that very few of them are smoking 16 pounds of weed over the course of a year. I mean, look at the cost alone: that's comfortably over $50K at dispensary prices, which I think probably outstrips the vast majority of folks' budgets for such things.
posted by dersins at 1:40 PM on June 2, 2016 [3 favorites]

And that's something that tends to get lost in the comparison between tobacco and weed- virtually nobody smokes weed in the quantities the average tobacco smoker smokes tobacco in.
posted by Pope Guilty at 2:05 PM on June 2, 2016 [4 favorites]

There's a handful of Israelis I know giving it the ol' college try, though.
posted by griphus at 2:14 PM on June 2, 2016 [2 favorites]

But they taught me in school that smoking a joint was as bad for your lungs as smoking two whole packs of cigarettes! Or something.
posted by Anticipation Of A New Lover's Arrival, The at 2:15 PM on June 2, 2016 [2 favorites]

But they taught me in school that smoking a joint was as bad for your lungs as smoking two whole packs of cigarettes! Or something.

Too bad this was when you were too yount to reply to bullshit with "Citation?"
posted by If only I had a penguin... at 2:23 PM on June 2, 2016 [1 favorite]

It's been years since I actively researched the cannabinoid receptors (and my research was small molecule drug development, not looking at actually smoking pot), but at the time there were numerous epidemiological studies showing no increased rate for lung cancer for stoners. In fact, I remember in at least some of the studies the incidence was reduced. THC also seems to have anti-tumor effects in vitro using cultured tumor cells.

Not sure about other lung diseases, however. I would still wager that smoking anything would increase one's risk for COPD. The jury is still out on the effects of vaping. Again, one would assume that vaping would reduce risk, but there isn't enough data yet to make that claim.
posted by Thoughtcrime at 2:27 PM on June 2, 2016 [3 favorites]

"Findings showed that cannabis use was associated with slightly better metabolic health (smaller waist circumference, lower body mass index, better lipid profiles, and improved glucose control)."

"Post hoc analyses showed that cannabis users brushed and flossed less than others and were more likely to be alcohol dependent "
posted by porpoise at 3:23 PM on June 2, 2016

"We don’t want people to think, ‘Hey, marijuana can’t hurt me,’ because other studies on this same sample of New Zealanders have shown that marijuana use is associated with increased risk of psychotic illness, IQ decline and downward socioeconomic mobility,” Meier said."

No. Impact of adolescent marijuana use on intelligence: Results from two longitudinal twin studies."

Highly powered studied looking at twins from the same household and compared a twin who used Cannabis and the twin who didn't.

"However, there was no evidence of a dose-response relationship between frequency of use and intelligence quotient (IQ) change. Furthermore, marijuana-using twins failed to show significantly greater IQ decline relative to their abstinent siblings. Evidence from these two samples suggests that observed declines in measured IQ may not be a direct result of marijuana exposure but rather attributable to familial factors that underlie both marijuana initiation and low intellectual attainment.

Other studies that show Cannabis use ~ Schizophrenia are typically highly flawed.

For example, Shakoor &al., 2015 (Psychotic experiences are linked to cannabis use in adolescents in the community because of common underlying environmental risk factors. Psych. Res. 227(2-3): 144-51) used the same survey on random kids as in Ronald &al., 2013 (Characterization of psychotic experiences in adolescence using the specific psychotic experiences questionnaire: findings from a study of 5000 16-year-old twins. Schiz. Bull. 40(4): 868-77) showed that the percentage of Cannabis users reporting hallucinations is similar to those who report hallucinations at least once a month among the general population of 16 year olds and reports of paranoia are similar to those who report paranoia at least once a week. The differences between non-Cannabis users and Cannabis users are statistically significant but the effect size is not terribly large.
posted by porpoise at 3:41 PM on June 2, 2016 [2 favorites]

I think there's somewhat ok evidence that cannabis use overall may increase the risk for later schizophrenia dx by around 2x, though the authors of this review point out that this is likely an upper bound. Since SZ is already a pretty common disease (~1% of pop'n), that's kind of a big increase in risk looking at it one way -- but to put it in perspective, it's not a lot bigger than the risk of living in an urban vs. a rural environment (~1.7x).

It also looks like there's some dose-response and maybe some effect of starting in early adolescence vs. later (not super comforting to me personally since I smoked weed for the first time as a 15-year-old, but there you go).

Anyway I don't think the evidence should be either ignored or sensationalized. As the authors say, "while it is important to avoid understating potential harms, which could put peoples’ health at risk, it is also important to avoid overstating the harms of cannabis, which could lead to the message being ignored when experience does not match the warnings given."
posted by en forme de poire at 4:51 PM on June 2, 2016 [3 favorites]

The sample group size was 1037, and of that 675 or 65% had smoked. A bit less than the 100% I was expecting. In the US it is around 44%

I thought for sure this was going to end with "...and that equals 420.
posted by Room 641-A at 5:39 PM on June 2, 2016

I just hate hate hate the implicit bias from a lot of research groups presupposing that Cannabis use is inherently bad. I'm too tired right now to look at that epidemiological study in detail, en forme de poire, but the title at least gets it right by using "Association" between use and psychosis.

Another thing that I really despise are the definitions of psychosis measured by researchers who likely have never gained experience* in the effects of Cannabis. "Marijuana psychosis" or "Psychotic events" are nothing like symptoms of schizophrenia and by using bs measurements, it takes away from the seriousness of bona fide schizophrenia (which is a highly complex spectrum disorder with highly diverse pathoetiologies; and yet the newest DSM lumps schizophrenia more tightly rather than acknowledge that it's a spectrum disorder).

AKT1 gene variants were identified that were associated with increased risk of schizophrenia and use (as well as COMT, but as numbers of individuals looked at increases, the association decreases) but as more individuals are analyzed, the effect size gets smaller and smaller.

One better hypothesis is that schizophrenia predisposes individuals to use (schizophrenia is more highly associated with nicotine and alcohol use than Cannabis - yet, is there anybody yelling from the rooftops that drinking causes schizophrenia, or that smoking cigarettes do?), rather than that use precipitates schizophrenia.

This is a very analogous circumstance as vaccines and autism - drug use typically begins at around or slightly before the age when schizophrenia typically manifests; it does not equate to that use leads to schizophrenia.

"It has been argued that even if we are uncertain that cannabis actually causes psychosis, it is better to err on the side of caution and warn cannabis users, psychiatric patients, and the general public about this potential danger of cannabis use. However, those adolescents most at risk for beginning cannabis use are already suspicious about official warning messages when it is perfectly clear that cannabis use is not approved by the general society. If we wish scientists to be taken seriously when we do discover real and substantial dangers, then we believe it would be better to avoid behaving like “the boy who cried wolf." Ksir & Hart 2016 (Cannabis and psychosis: a critical overview of the relationship. Curr. Pyshciatry Rep. 18(2): 12)

But, yes, youth should be discouraged from using psychoactive or entheogenic substances, including alcohol, because they are still developing coping mechanisms for life’s situations and narcotic use may impair the development of healthy life skills.

*which is different than a first time user predisposed to believing that it's terrible, ingests too much, in an improper setting, then declaring that marijuana is terrible and gave them "psychotic" experiences
posted by porpoise at 6:59 PM on June 2, 2016 [1 favorite]

That review breaks out psychotic symptoms from SZ specifically (sorry, didn't realize it was paywalled until I got home... grr); those figures were from the SZ-only association IIRC. One review I read (can't remember if it was that one) actually said the association was tighter between cannabis and SZ vs. cannabis and psychotic symptoms, which makes sense if the second category is fuzzy compared to an actual diagnosis of a psychotic illness.

I don't think the vaccines and autism comparison is a good one; in that case there's actually no increased risk when you look at kids receiving vaccines vs. kids who didn't. That's not like the current situation, in which cannabis users really do have elevated rates of SZ compared to non-users. Reverse causation is certainly a possibility, though there's some attempts to control for that with the "psychotic symptoms in pre-adolescence" variable and using pre- vs. post-legalization as a kind of "natural experiment"; probably there's also some "third variable affects both things" going on as well, since traumatic events increase SZ risk and may separately increase drug use. But while there isn't evidence that it's 100% forward causation, I also don't think there's a good reason to assume that it's 100% reverse or indirect causation either.
posted by en forme de poire at 8:43 PM on June 2, 2016 [1 favorite]

yeah. dry mouth is not good for gums. nor is burning shit and inhaling it into your mouth. i'm on like month 20 of a fucking highway restoration to restore my gums so my teeth don't fall out

NOW I USE MY VAPORIZER AND IT IS SO BOSS
posted by angrycat at 8:03 AM on June 3, 2016 [2 favorites]

Welp, since I don't smoke weed anymore, I guess this means I don't need to worry about flossing! That's the takeaway, right?
posted by duffell at 7:40 PM on June 3, 2016