Cannabis Users Have Lower Heart Rates, Study Finds
Want to listen to this article for FREE?
Complete the form below to unlock access to ALL audio articles.
Regular cannabis consumers tend to have a lower resting heart rate than those who don’t use the drug, according to a new study published in the American Journal of Medicine.
After analyzing the data of thousands of participants from an ongoing heart health study, researchers found that those who consumed cannabis had an average resting heart rate of 65.9 beats per minute (bpm), while those who didn’t use the drug had a slightly faster average heart rate of 68.3 bpm.
Marijuana heart rate - lower or higher?
Cannabis use is known to increase a person’s heartbeat directly after consumption, but the drug’s long-term effects on the organ are less well understood.
To find out more, a research team from the University of Bern and the University of California San Francisco looked at the data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, an ongoing initiative that’s recorded the heart health of 5,115 participants across the US since 1985.
Out of the 3,269 participants that attended the 30-year CARDIA follow-up assessment, 2,785 (85 percent) claimed to have never used cannabis, while 471 (14 percent) said they were regularly consuming the drug.
After comparing the heart health data of these two groups, the research team found that the cannabis-sober participants had an average resting heart rate of 68.4 bpm, while the cannabis-using participants had an average heart rate of 66.5 bpm.
Once the data had been adjusted for the participants’ demographics and health factors, the difference became starker; cannabis-sober participants had an average heart rate of 68.3 bpm, while cannabis-using participants had an average heart rate of 65.9 bpm.
There was no difference, however, between the heart rates of those who had no “cannabis years” (a measurement of how much cannabis the participants had collectively consumed in their lives) and those who had 10 cannabis years; after the data were adjusted, both groups had a heart rate of 68.2 bpm.
“Current cannabis use was associated with lower resting heart rate, but cumulative cannabis exposure was not,” the researchers concluded.
As such, the researchers hypothesized that cannabis may have acute but transient effects on the heart that only temporarily lower its cardiac output.
Cannabis and the heart
The American Journal of Medicine study may have its limitations – there were no data on how the participants consumed their cannabis or how much they used, for instance – but the research team say their findings still add to the body of evidence “suggesting a lack of deleterious association of cannabis use at a level typical of the general population on surrogate outcomes of cardiovascular disease.”
However, other studies have found that cannabis can have more concerning effects on heart health.
A paper published in the Canadian Medical Association Journal last September found that young adult cannabis consumers seem to be at a higher risk of having a heart attack than their cannabis-sober peers.
After assessing the survey data of thousands of young adults in the US, the research team found that 1.3 percent of self-identified cannabis consumers had a history of heart attacks, compared to around 0.8 percent of cannabis abstainers.
Research recently published in the Journal of Applied Physiology found that, compared to a control group, cannabis smokers had greater aortic stiffness, a factor linked to cardiovascular disease.
Another study published last year found that cannabis smoking can raise the levels of toxins in the blood, but not to the same extent seen in tobacco smokers.
However, many relevant researchers believe further studies are still needed to properly assess the cardiovascular effects of cannabis.
“We do acknowledge the limited scope of evidence defining the cardiovascular safety of marijuana at present,” Muthiah Vaduganathan, a cardiologist at Brigham and Women's Hospital, Massachusetts, told Analytical Cannabis in 2020. “However, based on what we know, we believe there is sufficient evidence to give us pause.”
“We believe broader-scale clinical research is needed to better understand the safety of marijuana, especially on cardiovascular health,” he added.