Cardiovascular effects linked to cannabis use independent of tobacco

By Melanie Hinze

Cannabis use may be associated with adverse cardiovascular outcomes, independent of tobacco use and a range of other demographic factors, according to research published recently in the Journal of the American Heart Association.

The researchers conducted a population-based cross-sectional study of data from the Behavioral Risk Factor Surveillance Survey, gathered between 2016 and 2020, from 29 US states and territories. They assessed the association between self-reported cannabis use over the past 30 days and the following self-reported cardiovascular outcomes: coronary heart disease, myocardial infarction (MI), stroke and a composite measure of all three.

Among the 434,104 participants aged 18 to 74 years (mean age, 45 years), the prevalence of daily cannabis use was 4% and nondaily use (about five days/month) was 7.1%, and 88.9% of participants had not used any cannabis.

After adjusting for demographic factors and tobacco smoking, the researchers found that daily cannabis use was associated with a 16% greater risk of coronary heart disease, a 25% increased risk of MI, a 42% increased risk of stroke and a 28% increased risk of the composite outcome compared with those who had never used cannabis. These risks were lower among those who used cannabis less frequently than daily users.

The association between cannabis use and increased cardiovascular risk was still evident in a separate analysis that included only those individuals who had never smoked tobacco. This found that daily cannabis use was associated with a 49% increased risk of MI, more than double risk of stroke and 77% increased risk of the composite outcome compared with never users of cannabis.

The researchers said their study was important because it suggested that cannabis use alone might be a risk factor for adverse cardiovascular outcomes.

According to the Australian National Drug Strategy Household Survey 2022-2023, 41% of Australians aged 14 years or older had ever used cannabis, 11.5% of people had used cannabis in the past month, whereas 25% of Australians had been offered or had the opportunity to use cannabis in the past 12 months. The number of people who had reported using cannabis in the previous month remained steady between 2001 and 2022 to 2023.

Professor Wayne Hall, Emeritus Professor at the National Centre for Youth Substance Use Research, The University of Queensland, Brisbane, said ‘This study provides cross-sectional evidence of an association between daily cannabis use (presumably by smoking) and some cardiovascular outcomes that survived adjustment for cigarette smoking.’

He said it added to a growing body of evidence that regular cannabis smoking might increase the risks of adverse cardiovascular outcomes.

‘The risks of adverse cardiovascular effects from cannabis smoking will be higher in older adults who use it for medical or nonmedical purposes, because these risks increase with age,’ he added.

‘These results are biologically plausible for cannabis smokers (given the adverse cardiovascular risks of tobacco smoking), but causal inference is limited because the data are cross-sectional rather than longitudinal,’ said Professor Hall.

J Am Heart Assoc 2024; 13: e030178 and