Will Smoking Pot Harm Your Heart? Experts Weigh In
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MONDAY, Jan. 22, 2018 (HealthDay News) — Anyone worried that smoking a lot of pot could lead to a heart attack or stroke will just have to keep worrying for the time being.
There’s not enough scientific evidence to say one way or the other how marijuana affects heart health, a new review has concluded.
“Our review found insufficient evidence to draw meaningful conclusions that marijuana use is associated with cardiovascular risk factors and outcomes,” said lead study author Dr. Divya Ravi, an internist with the Wright Center for Graduate Medical Education in Scranton, Pa.
For their review, Ravi and her colleagues pored through medical literature and found 24 studies that evaluated marijuana use and its effects on either heart health risk factors or actual health problems such as heart attack or stroke.
A few studies showed that pot use might benefit the heart, but these were contradicted by other studies that reported potential harmful effects, Ravi said.
For example, some studies linked marijuana use to less diabetes, lower blood sugar and higher levels of “good” HDL cholesterol, the researchers found. And despite anecdotal reports of marijuana bringing on the “munchies,” no studies have tied pot use to weight gain or obesity.
However, other studies found that smoking pot was associated with a greater risk for heart attack and death from heart disease.
“The evidence is insufficient to draw any conclusions,” Ravi said. “The association between marijuana and cardiovascular health has not been adequately studied to date.”
Two heart experts not involved with the study said they’re not surprised by the lack of evidence, given how difficult it is to conduct studies on marijuana use.
Results could become more definitive in the future, thanks to some states legalizing marijuana. That might make people more comfortable discussing their pot use with researchers, said Dr. Russell Luepker, a professor with the University of Minnesota’s School of Public Health.
The vast majority of states allow limited use of medical marijuana under certain circumstances. And eight states and Washington D.C. have legalized recreational pot use.
Dr. Satjit Bhusri, a cardiologist at Lenox Hill Hospital in New York City, said it’s very likely that smoking pot can harm heart health because you’re actively breathing in smoke.
“If you inhale a joint it’s like inhaling a cigarette — you’re putting toxins in your body,” Bhusri said.
On the other hand, it’s hard to say that eating or vaping marijuana produces the same heart risk, said Luepker, a spokesman for the American Heart Association.
“Like any smoked product, you inhale a variety of things, including carbon monoxide and other substances that you certainly don’t get if you eat it,” Luepker said.
Bhusri also expects that the more someone smokes pot, the more they’d increase their heart health risk.
“I wouldn’t be surprised if there is a dose relationship because of these toxins that are inhaled,” he said.
But because marijuana users don’t smoke at the same rate as those who smoke cigarettes, Luepker said, it’s not likely they will be doing themselves as much harm.
For instance, it’s hard to think of many people smoking two packs a day of pot, or lighting up first thing in the morning, he said.
Marijuana users are more akin to “social cigarette smokers who smoke a cigarette or two at a party, and they don’t seem to have any increased risk from that,” Luepker said.
Until more is known, though, pot users should use caution, Ravi concluded.
“At this juncture we have little data on potential harms or benefits associated with use to inform the counseling of marijuana users,” Ravi said. “It may be wise to proceed with caution until we have sufficient evidence to comment on the health effects of chronic marijuana use.”
The study is published in the Jan. 23 issue of Annals of Internal Medicine.
Copyright © 2018 HealthDay. All rights reserved.
Anyone worried that smoking a lot of pot could lead to a heart attack or stroke will just have to keep worrying for the time being.
Researchers analyzed more than a dozen studies on how marijuana affects your heart — here’s what they found
A study published in August claimed that marijuana users faced a threefold higher risk of dying from hypertension than those who had never used the drug.
The findings sounded alarming. But like any study, this one had key limitations, including the fact that it defined cannabis “users” as anyone who’d ever tried the drug. More importantly, however, it highlighted an important gap in our current understanding of the science of cannabis: How does the drug affect the heart?
A new paper highlights how clouded this picture currently is. Scientists simply don’t know the overall impact of cannabis on cardiovascular health.
For the new study, researchers in California, Pennsylvania, and New York looked at dozens of studies on marijuana and the heart. Those studies examined links between cannabis and health problems that put people at a higher risk of developing a heart condition — like high cholesterol or high blood pressure — as well as links between cannabis and actual heart conditions, such as heart disease .
But they found that all of the past studies were plagued by problems. Some were too small, others were too short-term, and others failed to study the right groups of people, such as those who would be the most at-risk for these conditions.
So the researchers came to a depressing conclusion: “Evidence examining the effect of marijuana on cardiovascular risk factors and outcomes . is insufficient,” they wrote.
That jibes with previous research on marijuana and the heart.
What we know about marijuana and heart health
There’s plenty of reason to be concerned about how marijuana impacts our health. Yet in many areas, we simply lack enough comprehensive research to draw any conclusions.
Scientists know that using marijuana increases your heart rate by between 20 and 50 beats a minute for anywhere from 20 minutes to three hours. That sounds like it could be enough to impact heart function, but again, we need more research.
A large, recent report from the National Academies of Sciences, Engineering, and Medicine found “insufficient evidence” to support or refute the idea that cannabis might increase the overall risk of a heart attack, though it also found some limited evidence that using the drug could be a trigger for the phenomenon.
Another study, albeit a very small one, found an increase in blood pressure — but only when regular pot users stopped using the drug, not before. That aligns with research from the Mayo Clinic, which suggests that using cannabis could result in decreased, not increased blood pressure.
With this in mind, Francesca Filbey, director of cognitive neuroscience research of addictive disorders at the Center for Brain Health, told Business Insider in August that future studies should assess a wider range of factors linked with cannabis use and heart health. That could include weight, BMI, and the use of other substances.
How one study came to such a stark conclusion
Given the limits of our knowledge about marijuana and heart health, how did one study come to such stark conclusions about the drug and our hearts? As it turns out, multiple factors muddled the picture, including the authors’ decision to define “regular” marijuana users as anyone who’d ever tried weed.
A statistical analysis suggested that the people deemed marijuana users were 3.42 times as likely to die from hypertension, or high blood pressure, than those who said they had never used. That risk also appeared to rise by a factor of 1.04 with what the researchers labeled “each year of use.”
That’s a pretty stark finding. But in reality, more than half of Americans have tried cannabis, which would classify all of them as users in this study. Just a fraction of those people use it regularly, according to recent surveys.
In addition, the study was observational, meaning it followed a group of people over time as opposed to assigning specific groups to try specific interventions. That type of study cannot be used to conclude that there’s a cause-and-effect relationship between two things, which the authors acknowledged in their paper.
Findings from an analysis of marijuana's effect on the heart contradict the notion that marijuana smokers face a higher risk of dying from hypertension.