> researchers were unable to account for several potential confounding factors including the duration and amount of cannabis use or the use of tobacco or other drugs.
Personally I'd wager a bet it's the tobacco and/or smoking that is the harmful part, but it kind of dumbfounds me they failed to account for "details" like "duration and amount of cannabis use", that feels like a very vital thing to control for. Nothing is good for you in too great amounts, even water, so not taking that into account seems to not really give reliable and trustworthy results.
Exactly. Being unable to account for this covariate (tobacco use) pretty much invalidates this analysis. The odds ratio for tobacco use is basically the same (3x).
This article refers to two studies. The retrospective study of 4.6 million people did account for tobacco use.
> The findings are from a retrospective study of over 4.6 million people published in JACC Advances and a meta-analysis of 12 previously published studies being presented at the American College of Cardiology's Annual Scientific Session (ACC.25).
> Kamel and his team conducted the retrospective study using data from TriNetX, a global health research network that provides access to electronic medical records. Their findings indicate that over an average follow-up of over three years, cannabis users had more than a sixfold increased risk of heart attack, fourfold increased risk of ischemic stroke, twofold increased risk of heart failure and threefold increased risk of cardiovascular death, heart attack or stroke. All study participants were younger than age 50 and free of significant cardiovascular comorbidities at baseline, with blood pressure and low-density lipoprotein (LDL) cholesterol levels within a healthy range and no diabetes, tobacco use or prior coronary artery disease.
Many people have had cardiologists say they have perfectly fine hearts go on to have heart attacks months later. My brother was one of these people. He was going in for spinal surgery, cardio said his heart was fine. Two weeks after surgery he was short of breath. Turns out he needed a triple bypass.
And that was a physical change. Heart attacks happen because of electrocardiac issues as well.
I wonder about all the confounding effects. In my country (famous for cannabis to be easy to come by (for decades already), and I saw many smoke from age 16 up as I grew up in 90's, 00's). I have always felt that the heavy cannabis smokers had something to compensate; stress, unrest, impending depression, friction with parents. It was never the healthy sporty types with fulfilling relationships, good grades or a nice career that smoke cannabis heavily (like daily). Sure, some of those smoked, but more occasionally.
but sure, still lets make to account by other "legal" substances (alco, tobacco, cocaine, pharmaceutics and other "lifestyle choices" infecting cardiovascular system)
and way they are consumed(smoked, ingested, pure or with say tobacco)
would love see data for a group who consumes cannabis by ingestion and especially not via smoking!
also- do they differ different thc/cbd grades used (high/low thc, "medical")?
im regards "research demonstrates something does this.." for many years alcohol was considered "healthier" over non consumption, just becauses non-drinkers were together with those of abstinent ex-alcholics.. thus average score was lower than for those who drunk minimal amounts and were considered "healthier".
For me, cannabis causes anxiety, and it’s pretty well established that anybody with anxiety or bipolar or schizophrenia should not be using cannabis because it can make these much worse. I don’t suffer anxiety anymore, but there’s plenty of scientific evidence about the relationship between anxiety and cannabis use.
Would be nice to know how much of a role a sedentary lifestyle plays in it or if it puts everyone at risk regardless of other habits. Maybe this just means you need to do cardio several times a week to keep using THC.
FWIW, I've smoked cannabis daily for maybe 15 years, I'm not exactly sedentary (have dogs, a partner and like to (lazily) swim in the sea) but generally don't exercise. Visited a cardiologist like two months ago and have perfectly fine heart despite the smoking.
Anecdotal of course, many could probably bring up counter-stories too, but I do think you bring up a good point, it seems to me a completely sedentary lifestyle seems to be way more destructive to your health than moderate usage of various drugs and/or eating habits. People who just walk a bit daily already seem way healthier and happier than peers in their same age.
Some commenters here talking about anxiety, but I think the bigger cause, which many people don't know, is that THC significantly increases your heart rate despite it's usual characterization as a depressant. If I recall correctly (big "if" considering the circumstances hah) my heart rate after smoking would go up by 10-20 BPM (from 65-70 to 80-90) while still feeling relaxed; ~~finding some numbers on this from a reputable source is difficult right now and this symptom is suspiciously missing from the wikipedia page~~.
Edit:
Realized this comment sounds like fear mongering, so decided to dig up some actual sources. The wiki page I needed to find was:
Not really related, but the other thing I found out recently that cannabis can cause is the worst panic attack I have ever experienced: a DPDR (derealization / depersonalization) panic attack. I’ve had regular panic attacks before. I get one a year, roughly, where I get essentially heart attack symptoms. But this was something else. It felt like something was truly, irrevocably broken with my mind and I couldn’t even describe what. Utterly terrifying. I was a heavy user but dropped it the next day.
THC increases glutamate release[1], which is most likely the source of this panic. I have psychotic episodes even with a a few big hits but then again I have schizoaffefctive disorder. Glutamate is my arch enemy.
I had a similar experience when I was young. Bought a vape and some Cannabis, which probably had really high THC concentration as it tends to have nowadays. Took a bit, didn't feel anything, then took a bit more, and boom, a panic attack. Might even had some hallucinations, I'm not fully sure what was real and what wasn't.
After the experience I felt kind of weird and "slow" for several days. Later I found out that there is also a genetic risk of schizophrenia in my family. No way I'm going to touch anything with THC ever again. I've tried CBD oil though and that was okay, slightly calming effect. But ultimately I prefer beer over that too.
Anecdotally this isn't uncommon among heavy users, I've heard of similar things happen to a few people. You did the right thing stopping, where people really go off the deep end is when they don't listen to the warning signs and keep blazing.
I think weed should be legal and for the majority of people used in moderation it's going to be fine, but at the end of the day it's a psychoactive drug. It's probably not optimal to use it daily and in particular waking and baking every day is asking for trouble.
Also a case to be made that modern strains are worse. I fully believe that the risk of losing the plot is higher when you're smoking some lemon sherbet bubblegum flavours every day instead of old fashioned moroccan hash
Without a clear mechanism of action, this sure requires monitoring (like any drug), but the conclusions are terribly oversold. Correlation does not imply causation, no matter the sample size
Literally no mention of ROA. It matters whether they smoke plant matter, vape, use it orally, etc. This, combined with their inability to account for a number of other factors such as tobacco use, makes this study literally useless. Earned a flag from me.
Substances approved by the FDA are done based on specific treatments, with multiple trials and approval per use case
Substances declared scheduled are illegal by the substance itself, instead of per use case
paradoxically because there is no FDA approved use case and almost no way to get one
meaning that places in the US that diverge in legality and are ignored by the federal government have done so without any clinical trial, which would be some level of peer reviewed objective information by use case instead of the whole substance
we can’t even get a simple list of side effects, or a disclaimer about what kind of users shouldn’t use it
The US government is now in thrall to the Kratom industry though isn't it? No reason to expect any logical consistency from them.
(Literally the person currently responsible for the branch of government that keeps illegal drugs out of the country is an investor in a Kratom company)
which blocks the receptor that THC binds to and led to weight loss and further improvements of the “metabolic syndrome” beyond weight loss alone. Unfortunately it caused major depression in some people including suicide.
So looking at it that way it would be no surprise that cannabis causes weight gain and metabolic syndrome and in fact my experience is that if I am using cannabis I get a few kg. I think that is the THC and on top of that if you are smoking you are inhaling small particles that turn your blood into sludge (e.g. your blood is a “complex fluid” with cells in it that can be damaged) and doing damage to your lungs and capillaries and promoting inflammation and all that.
> researchers were unable to account for several potential confounding factors including the duration and amount of cannabis use or the use of tobacco or other drugs.
Personally I'd wager a bet it's the tobacco and/or smoking that is the harmful part, but it kind of dumbfounds me they failed to account for "details" like "duration and amount of cannabis use", that feels like a very vital thing to control for. Nothing is good for you in too great amounts, even water, so not taking that into account seems to not really give reliable and trustworthy results.
Edible forms of cannabis raise heart rate and blood pressure substantially as well.
I tried to look up the source article, but there doesn’t seem to be any mention of consumption of edibles versus smoking.
Exactly. Being unable to account for this covariate (tobacco use) pretty much invalidates this analysis. The odds ratio for tobacco use is basically the same (3x).
Also, title needs a 2025.
This article refers to two studies. The retrospective study of 4.6 million people did account for tobacco use.
> The findings are from a retrospective study of over 4.6 million people published in JACC Advances and a meta-analysis of 12 previously published studies being presented at the American College of Cardiology's Annual Scientific Session (ACC.25).
> Kamel and his team conducted the retrospective study using data from TriNetX, a global health research network that provides access to electronic medical records. Their findings indicate that over an average follow-up of over three years, cannabis users had more than a sixfold increased risk of heart attack, fourfold increased risk of ischemic stroke, twofold increased risk of heart failure and threefold increased risk of cardiovascular death, heart attack or stroke. All study participants were younger than age 50 and free of significant cardiovascular comorbidities at baseline, with blood pressure and low-density lipoprotein (LDL) cholesterol levels within a healthy range and no diabetes, tobacco use or prior coronary artery disease.
I know you can't judge a study by its abstract, but they don't even mention the dosing mechanism, it's just "cannabis use".
> Nothing is good for you in too great amounts, even water
https://youtube.com/watch?v=XewVicFzRxw&t=152s
Do you smoke?
Literally just wrote about that: https://news.ycombinator.com/item?id=48794178
> I've smoked cannabis daily for maybe 15 years [...] Visited a cardiologist like two months ago and have perfectly fine heart despite the smoking.
Many people have had cardiologists say they have perfectly fine hearts go on to have heart attacks months later. My brother was one of these people. He was going in for spinal surgery, cardio said his heart was fine. Two weeks after surgery he was short of breath. Turns out he needed a triple bypass.
And that was a physical change. Heart attacks happen because of electrocardiac issues as well.
I wonder about all the confounding effects. In my country (famous for cannabis to be easy to come by (for decades already), and I saw many smoke from age 16 up as I grew up in 90's, 00's). I have always felt that the heavy cannabis smokers had something to compensate; stress, unrest, impending depression, friction with parents. It was never the healthy sporty types with fulfilling relationships, good grades or a nice career that smoke cannabis heavily (like daily). Sure, some of those smoked, but more occasionally.
> stress, unrest, impending depression, friction with parents
Well, Id guess these are reasons for any case of substance missuse?
Wouldn't they also be potential causes that lead to worse heath outcomes that were not measured in the study?
6x sounds too clickbaity.
but sure, still lets make to account by other "legal" substances (alco, tobacco, cocaine, pharmaceutics and other "lifestyle choices" infecting cardiovascular system) and way they are consumed(smoked, ingested, pure or with say tobacco)
would love see data for a group who consumes cannabis by ingestion and especially not via smoking!
also- do they differ different thc/cbd grades used (high/low thc, "medical")?
im regards "research demonstrates something does this.." for many years alcohol was considered "healthier" over non consumption, just becauses non-drinkers were together with those of abstinent ex-alcholics.. thus average score was lower than for those who drunk minimal amounts and were considered "healthier".
For me, cannabis causes anxiety, and it’s pretty well established that anybody with anxiety or bipolar or schizophrenia should not be using cannabis because it can make these much worse. I don’t suffer anxiety anymore, but there’s plenty of scientific evidence about the relationship between anxiety and cannabis use.
That's a very blanket statement, lots of people are in fact prescribed low dose cannabis for anxiety.
The term “cannabis” stems from the Greek kánnabis and earlier Scythian and Akkadian references such as qunubu.
Would be nice to know how much of a role a sedentary lifestyle plays in it or if it puts everyone at risk regardless of other habits. Maybe this just means you need to do cardio several times a week to keep using THC.
FWIW, I've smoked cannabis daily for maybe 15 years, I'm not exactly sedentary (have dogs, a partner and like to (lazily) swim in the sea) but generally don't exercise. Visited a cardiologist like two months ago and have perfectly fine heart despite the smoking.
Anecdotal of course, many could probably bring up counter-stories too, but I do think you bring up a good point, it seems to me a completely sedentary lifestyle seems to be way more destructive to your health than moderate usage of various drugs and/or eating habits. People who just walk a bit daily already seem way healthier and happier than peers in their same age.
Some commenters here talking about anxiety, but I think the bigger cause, which many people don't know, is that THC significantly increases your heart rate despite it's usual characterization as a depressant. If I recall correctly (big "if" considering the circumstances hah) my heart rate after smoking would go up by 10-20 BPM (from 65-70 to 80-90) while still feeling relaxed; ~~finding some numbers on this from a reputable source is difficult right now and this symptom is suspiciously missing from the wikipedia page~~.
Edit:
Realized this comment sounds like fear mongering, so decided to dig up some actual sources. The wiki page I needed to find was:
https://en.wikipedia.org/wiki/Effects_of_cannabis
Also, the CDC page mentions it:
https://www.cdc.gov/cannabis/health-effects/heart-health.htm...
And links to this paper (though I can't read past the abstract bc no institutional access):
https://doi.org/10.1002/j.1552-4604.2002.tb06005.x
Not really related, but the other thing I found out recently that cannabis can cause is the worst panic attack I have ever experienced: a DPDR (derealization / depersonalization) panic attack. I’ve had regular panic attacks before. I get one a year, roughly, where I get essentially heart attack symptoms. But this was something else. It felt like something was truly, irrevocably broken with my mind and I couldn’t even describe what. Utterly terrifying. I was a heavy user but dropped it the next day.
THC increases glutamate release[1], which is most likely the source of this panic. I have psychotic episodes even with a a few big hits but then again I have schizoaffefctive disorder. Glutamate is my arch enemy.
[1] https://link.springer.com/article/10.1186/s42238-025-00277-9
I had a similar experience when I was young. Bought a vape and some Cannabis, which probably had really high THC concentration as it tends to have nowadays. Took a bit, didn't feel anything, then took a bit more, and boom, a panic attack. Might even had some hallucinations, I'm not fully sure what was real and what wasn't.
After the experience I felt kind of weird and "slow" for several days. Later I found out that there is also a genetic risk of schizophrenia in my family. No way I'm going to touch anything with THC ever again. I've tried CBD oil though and that was okay, slightly calming effect. But ultimately I prefer beer over that too.
Anecdotally this isn't uncommon among heavy users, I've heard of similar things happen to a few people. You did the right thing stopping, where people really go off the deep end is when they don't listen to the warning signs and keep blazing.
I think weed should be legal and for the majority of people used in moderation it's going to be fine, but at the end of the day it's a psychoactive drug. It's probably not optimal to use it daily and in particular waking and baking every day is asking for trouble.
Also a case to be made that modern strains are worse. I fully believe that the risk of losing the plot is higher when you're smoking some lemon sherbet bubblegum flavours every day instead of old fashioned moroccan hash
Can relate to this experience. How old were you?
Without a clear mechanism of action, this sure requires monitoring (like any drug), but the conclusions are terribly oversold. Correlation does not imply causation, no matter the sample size
Literally no mention of ROA. It matters whether they smoke plant matter, vape, use it orally, etc. This, combined with their inability to account for a number of other factors such as tobacco use, makes this study literally useless. Earned a flag from me.
Agree on ROA, but the retrospective cohort study (one of two discussed in this article) did account for many other factors including tobacco use.
people just want their recreational drugs
it's as stupid as smoking/vaping and not even black box warnings will get people to stop
now if you need pain management I can respect that 100%
but you need to investigate Palmitoylethanolamide and Geraniol as alternatives
* https://news.ycombinator.com/item?id=48700498
Can you respect folks who are treating mental/emotional pain or just physical?
I’m annoyed by the bifurcated regulatory regime
Substances approved by the FDA are done based on specific treatments, with multiple trials and approval per use case
Substances declared scheduled are illegal by the substance itself, instead of per use case
paradoxically because there is no FDA approved use case and almost no way to get one
meaning that places in the US that diverge in legality and are ignored by the federal government have done so without any clinical trial, which would be some level of peer reviewed objective information by use case instead of the whole substance
we can’t even get a simple list of side effects, or a disclaimer about what kind of users shouldn’t use it
only anecdotes
that annoys me and it’s not just about weed
The US government is now in thrall to the Kratom industry though isn't it? No reason to expect any logical consistency from them.
(Literally the person currently responsible for the branch of government that keeps illegal drugs out of the country is an investor in a Kratom company)
Yes we are living in a kleptocracy / kakistocracy hybrid
Good. This crap has been to normalized, especially online.
It’s starting to look like THC ( found in gummies, too ) causes vascular problems.
You get the munchies
https://www.youtube.com/watch?v=yN1AQDxwrSg
Before we got Ozempic there was great hope for
https://en.wikipedia.org/wiki/Rimonabant
which blocks the receptor that THC binds to and led to weight loss and further improvements of the “metabolic syndrome” beyond weight loss alone. Unfortunately it caused major depression in some people including suicide.
So looking at it that way it would be no surprise that cannabis causes weight gain and metabolic syndrome and in fact my experience is that if I am using cannabis I get a few kg. I think that is the THC and on top of that if you are smoking you are inhaling small particles that turn your blood into sludge (e.g. your blood is a “complex fluid” with cells in it that can be damaged) and doing damage to your lungs and capillaries and promoting inflammation and all that.