- Researchers report that cannabis has an significant association with higher odds of stroke and heart attack.
- They say that any form of ingestion can have effects on heart health.
- The number of people using cannabis has increased significantly in recent years.
Cannabis has a significant association with increased odds of stroke and heart attack among adults, including those who don’t use tobacco.
In addition, the odds of having a stroke or heart attack increases among those who use cannabis more frequently.
Those are the findings of a
In their study, researchers analyzed the results of an annual survey of 430,000 adults in the United States from 2016 through 2020.
The study authors said in a
The increase of combined risk of stroke, heart attack, and coronary heart disease was similar to the risk among adults who never used e-cigarettes but did use cannabis.
According to the 2019 National Survey on Drug Use and Health from the U.S. Department of Health and Human Services, the number of people using cannabis has increased significantly in recent decades.
The annual survey stated that in 2019 that 48 million people 12 or older reported using cannabis at least once, compared to nearly 26 million people ages 12 or older in 2002.
Cannabis is illegal at the federal level, but it is now legal in some form in 40 states and Washington D.C.
“Despite common use, little is known about the risks of cannabis use and, in particular, the cardiovascular disease risks,” said Abra Jeffers, PhD, a lead study author and a data analyst at Massachusetts General Hospital in Boston in the statement. “The perceptions of the harmfulness of smoking cannabis are decreasing, and people have not considered cannabis use dangerous to their health. However, previous research suggested that cannabis could be associated with cardiovascular disease. In addition, smoking cannabis — the predominant method of use — may pose additional risks because particulate matter is inhaled.”
The survey data came from the
The research team looked at whether cannabis use was associated with adverse cardiovascular outcomes among the general adult population, among people who never smoked tobacco or used e-cigarettes, and among younger adults (men under 55 and women under 65) at risk for heart disease.
They also factored in the number of days per month that people used cannabis.
The analyses of cannabis use (smoked, eaten, or vaporized) was associated with more adverse cardiovascular outcomes, such as stroke, coronary heart disease, and myocardial infarction.
With more frequent use (more days per month), the odds of adverse outcomes were higher. The results were similar after controlling for other cardiovascular risk factors, including alcohol use, tobacco and/or e-cigarette use, physical activity, body mass index, and type 2 diabetes.
Non-users had a lower risk of heart issues than both daily and non-daily cannabis users. Daily users were 25% more likely to suffer a heart attack than non-users.
Daily cannabis users were also 42% more likely to have a stroke higher compared to non-users. There was also a lower risk for less-than-daily users.
Cannabis use was associated with 36% higher odds for premature stroke, heart attack, and cardiovascular disease among younger adults at risk for premature cardiovascular disease, regardless of whether they also used traditional tobacco products or not.
An analysis of a smaller subgroup of younger adults who never smoked tobacco cigarettes or used nicotine e-cigarettes found a significant association between cannabis use and increased odds of stroke, heart attack, and coronary heart disease.
Survey participants were 18 to 74 years old with an average age of 45. About half identified as female, 60% identified as white adults, 11% identified as Black adults, 19% identified as Hispanic adults and nearly 9% identified as other.
Nearly 90% of the adults didn’t use cannabis, 7% used less than daily, and 4% used daily.
Of users, nearly 74% reported smoking it. More than 60% never used tobacco cigarettes, 28% of daily cannabis users never used tobacco cigarettes, 44% of non-daily cannabis users never smoked tobacco cigarettes, and nearly 64% of participants didn’t use cannabis and had never smoked tobacco cigarettes.
“Our sample was large enough that we could investigate the association of cannabis use with cardiovascular outcomes among adults who had never used tobacco cigarettes or e-cigarettes,” Jeffers said. “Cannabis smoke is not all that different from tobacco smoke, except for the psychoactive drug: THC vs. nicotine. Our study shows that smoking cannabis has significant cardiovascular risk risks, just like smoking tobacco. This is particularly important because cannabis use is increasing and conventional tobacco use is decreasing.”
The authors acknowledged several study limitations, including that much of the information was self-reported and that researchers didn’t have participants’ baseline lipid profile or blood pressure.
The study also used data for only a single point in time. The authors said prospective cohort studies are necessary, following groups of individuals over time.
Dr. Cheng-Han Chen is an interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in California.
Chen, who wasn’t involved in the study, told Medical News Today that as cannabis use increases, we’re only now understanding its effect on heart health.
Even then, he said there’s plenty of evidence linking cannabis to heart attacks and strokes.
“Given this evidence, we may soon be seeing more public health recommendations to avoid cannabis use, similar to our recommendations to avoid tobacco use,” Chen said. “This would be especially important to people with pre-existing cardiovascular disease or with cardiovascular risk factors.
Chen noted that researchers are discovering ingesting THC increases systolic absorption of the chemical when compared to smoking THC, and thus results in greater adverse effects.
“However, cannabis smoke comes with a separate set of health concerns as the smoke contains many carcinogens and mutagens similar to tobacco smoke,” he said.
Loren Wold, an expert in inhaled products and cardiovascular risk at The Ohio State University Wexner Medical Center who wasn’t involved in the research, told Medical News Today the study’s inclusion of cannabis use by ingestion hasn’t been reported before in such a large study.
“It is very important to understand that it does not appear to [just] involve the inhalation of particulate matter from inhalation – smoking or vaping cannabis – but any form of ingestion can have effects on heart health,” Wold said.
Wold said as cannabis becomes more mainstream, it’s important for these studies to gain a wider audience.
“It is important for policymakers to understand the potential cardiovascular risk to younger and older adults should these products continue to be legalized,” she said.
Dr. Mary Greene, a cardiologist with Manhattan Cardiology in New York City who wasn’t involved in the study, told Medical News Today this research has been a long time coming.
“In the field of cardiology, we have long suspected cannabis to be related to an increased risk of poor cardiovascular outcomes – heart attack, heart failure and stroke – but there has been insufficient evidence as many studies were not designed or powered for these specific outcomes,” Greene said. “This study addresses this specifically. There have been sentinel cardiovascular studies since the early 2000s that have suggested this.”
“And these findings are striking, indicating a 36 percent increased risk of heart disease and heart attack and a 42 percent increase in the risk of stroke. So, this study is validating what we have seen in past studies,” she said.
Greene said the study shows the method of consumption doesn’t matter
“There is a clear dose-response relationship with the outcomes, meaning that the more regularly the THC is consumed, the greater the chance of a major adverse cardiovascular event,” Greene said. “Those risks increase with each number of cardiovascular risk factors that are additionally present (like) diabetes, smoking etc. If you have an underlying cardiac risk factor, it may be a bad idea to consume THC regularly.”
“Of course when prescribed medically, one must weigh risks and benefits when consulting with their prescribing physician,” she added.
Daniele Piomelli, the director of the UC Irvine Center for the Study of Cannabis in California who wasn’t involved in the study, told Medical News Today that cross-sectional survey studies such as this can’t necessarily demonstrate cannabis is bad for you, for two reasons.
“First, they are not designed to show a causative link between cannabis use and health outcomes; and second, surveys are intrinsically biased,” Piomelli said. “Some folks answer, others don’t, and one does not know why.”
“We don’t take too seriously the innumerable surveys showing that ‘cannabis is good for you,’, so we should apply the same critical spirit to studies that claim to show the opposite,” he added.
Dr. Saint Anthony Amofah, the executive vice president, chief clinical officer, and chief academic officer at Community Health of South Florida who wasn’t involved in the research, told Medical News Today that in the case of this study, size matters.
“With 430,000 people studied, this is a strong study, which adds to the bank of knowledge that this is a real concern,” Amofah said. “In recent years, we have seen similar studies but not of this size and scope.”
Amofah said the study shows “There is a misplaced perception that cannabis is good and safe, but that view, as we can see from this study, is inaccurate.”
“But some believe increased health risks have to do with the mode of consumption, whether you are smoking it or ingesting it as an edible or consuming it through a vaporizer,” he said. “But this study, unlike other studies, showed that no matter how you took it, cannabis presented significant increased health risks. The huge sample size for this study.”
Amofah added the study justifies spreading the word.
“The next step is to do what we can as part of the medical community to get the message out to the public that cannabis isn’t good for you,” he said.