It might be time to seriously rethink our attitudes to cannabis use.
New research has found that those who take the drug are twice as likely to die from cardiovascular disease, and are at increased risk of other major adverse cardiovascular events (MACE).
Cannabis is being legalized in more and more places worldwide, increasing medicinal and recreational use – but it may warrant closer monitoring by health professionals. The researchers here, led by a team from the University of Toulouse in France, wanted to look more closely at potential health risks that had previously been flagged.
They looked at 24 previous studies published between 2016 and 2023, involving around 200 million people. Overall, the increased risk linked to cannabis use was 29 percent for acute coronary syndrome (reduced blood flow to the heart), 20 percent for strokes, and 100 percent for cardiovascular disease mortality.
“The findings reveal positive associations between cannabis use and MACE,” write the researchers in their published paper. “These findings should encourage investigating cannabis use in all patients presenting with serious cardiovascular disorders.”
There are some limitations worth bearing in mind here. The studies included in the research differed in terms of how they defined cannabis use, relied on self-reporting, and didn’t measure use of the drug over time. That makes them less statistically robust.
The research also notes a high risk of bias in the majority of studies investigated, due to the way they were structured.
And it’s important to say the research doesn’t show direct cause and effect, only an association. It’s possible that other factors not considered here are driving both cannabis use and heart health issues in certain groups of people.
Nevertheless, the large number of people surveyed on their real-world use of cannabis counts in the study’s favor. It also has more recent data than many other studies, and we know that cannabis use and composition is changing over time.
That’s enough to warrant deeper investigation into the possible health risks.
“Legalizing the drug and expanding its medical use worldwide have likely contributed to profound changes in the general perception of cannabis and to the overall rise in cannabis consumption,” write the researchers.
“Consequently, users’ profiles and consumption habits profoundly differ from those in the 2010s, especially as cannabis products show an increasing trend in potency, with rising concentrations of delta-9-tetrahydrocannabinol (THC).”
Further research is absolutely needed here, not least to determine whether the chemicals and compounds in cannabis – of which there are hundreds – could be leading to these health risks, and how taking cannabis in different forms, such as inhalables or edibles, might have an influence.
Previous studies have already shown how the drug can increase the risk of cancer, and significantly alter our DNA, for example. Cannabis could also trigger psychosis through the impact it has on the brain.
The new study is accompanied by an editorial written by epidemiologists Stanton Glanz and Lynn Silver, from the University of California San Francisco. In it, Glanz and Silver argue that as cannabis use rises, more should be done to educate people about the risks – as has been done with cigarettes.
“Specifically, cannabis should be treated like tobacco: not criminalized but discouraged, with protection of bystanders from secondhand exposure,” they write.
The research has been published in the journal Heart.
