- Researchers say frequent cannabis use can raise the risk of a heart attack in adults younger than 45.
- The reason for the connection isn’t entirely known, but experts say it could be related to higher heart rates and blood pressures attributed to cannabis use.
- The actual number of heart attacks in study participants was low, but experts say the new study provides individuals and healthcare professionals with information to consider before cannabis use.
A new study released Sept. 7 says adults younger than 45 years old who use cannabis were twice as likely to have had a heart attack, with the likelihood greater in more frequent users.
The number of incidents of heart attack was still small among the study participants.
Nonetheless, researchers report that the findings, published in the Canadian Medical Association Journal, line up with other studies demonstrating a link between frequent cannabis use and heart attacks (acute myocardial infarction) in hospital settings.
The latest study examines the frequency of cannabis use and method of consumption with the risk of heart attack in younger adults who typically aren’t at high risk because of their age.
“With recent legalization and decriminalization, cannabis use is increasing in young adults in North America, and we do not fully know its effects on cardiovascular health,” Dr. Karim Ladha, a clinician scientist at Unity Health Toronto, said in a press release. “We found an association between recent cannabis use and myocardial infarction, which persisted across an array of robust sensitivity analyses.
“This association was consistent across different forms of cannabis consumption, including smoking, vaporization, and other methods such as edibles,” Ladha added. “This suggests that no method of consumption is safer than another in this regard.”
Researchers examined data from a survey conducted by the Centers for Disease Control and Prevention (CDC).
The study included 33,000 adults between the ages of 18 and 44, more than 17 percent of whom said they used cannabis within the previous 30 days.
Of those users, 1.3 percent (61 of 4,610) reportedly experienced heart attacks. Of the noncannabis users, 0.8 percent (240 of 28,563) reportedly had heart attacks.
The cannabis users were more likely to be men who smoke cigarettes, e-cigarettes and drink alcohol heavily, which also may have contributed to their higher risk. But those factors, as well as others that could contribute to heart attacks, were adjusted for the analysis.
Researchers noted that the study provides information on the relationship between cannabis use and heart attacks but not the biological mechanism.
“Cannabis can induce MIs (myocardial infarctions) through several different mechanisms, but the data is often convoluted and difficult to determine, as many individuals smoke both cannabis and cigarettes, which is also a risk factor for heart disease and heart attacks,” Dr. Monty Ghosh, an assistant clinical professor in the Department of General Internal Medicine and Neurology at University of Alberta in Canada, told Healthline.
“With cannabis, especially THC, we see an increase in heart rate as well as blood pressure, both of which can be quite fast, which can precipitate a heart attack. This is especially true after the first hour of use,” he added.
“There are other possible causes, including spasming of heart vessels decreasing blood flow to the heart, causing a heart attack,” Ghosh explained. “There is also a concern that it can cause platelets to become more sticky, which can block the vessels. The vast majority of MIs occurred in individuals who smoked cannabis, as opposed to ingesting it.”
Study researchers said they analyzed behavioral risk factor data, along with the heart attack data, because it was the best available source for providing insights, which are generalizable and nationally representative, Nikhil Mistry, a PhD candidate at the University of Toronto, said in the press release.
“As a young adult, it is important to be aware of the risks associated with cannabis use, especially in the current climate where we are exposed to a wealth of misinformation and nonevidence-based health recommendations,” Mistry said.
Cannabis advocates say the drug can have medical benefits if used responsibly and in moderation, including better sleep, mood, focus, and digestion.
However, doctors also need to be aware of the potential relationship between cannabis and heart attacks in younger adults, said Dr. David Mazer, a clinician scientist at Unity Health in Toronto.
“Cannabis use should be considered in cardiovascular health risk assessment,” Mazer said in the press release. “When making decisions about cannabis consumption, patients and physicians should consider its associated benefits and risks in the context of their own health risk factors and behaviors.”
Study authors concluded, “The large sample size, generalizability, and detailed data on cannabis consumption of the cross-sectional study provide unique insight into this growing public health concern. Further studies and more data are needed to confirm these findings and elucidate the mechanisms contributing to cannabis-associated cardiovascular outcomes.”