Is Smoking Weed Bad for Your Heart?

Is Smoking Weed Bad for Your Heart?

It’s 2024, and you’re just out here trying to give a damn. Perhaps you’ve considered making the “healthy” swaps that talking-head docs on TV have promised will fix everything: fish instead of red meat, dark chocolate for milk, water for soda. Maybe you’ve even subbed out wine for weed, especially since research shows that drinking alcohol can be really hard on your heart. But, as ever, taking care of yourself isn’t quite as all-or-nothing as “one thing is definitively good for you, and the other is definitively bad for you.” In the case of cannabis, a growing pool of research indicates that weed might spell trouble for your cardiovascular health, too. (Heavy sigh while exhaling a huge cloud of smoke.)

The move to use cannabis in place of alcohol is a wide-reaching wellness trend, as you probably know from all the hype that surrounded Dry January. Celebrities like John Mayer have reportedly made a permanent switch from alcohol to cannabis, too. As Mayer told Rolling Stone, “I put [weed] where drinking used to go, and the quality of life has gone up considerably.” Country music legend Willie Nelson, too, is reportedly “California sober,” a term that means a person isn’t using hard drugs or drinking alcohol, but still doin’ the weed. Meanwhile, cannabis-infused beverages have shown up to rival canned cocktails on store shelves, and edibles have expanded beyond gummies and into popcorn, hot sauces, and coffee—meaning there’s a huge array of fun new ways to get stoney bologna.

It makes sense that weed is having a moment: Since the mid-2010s, when some states began legalizing cannabis, more people in the US are using it. A 2022 report from the Substance Abuse and Mental Health Services Administration indicates that 22% of people 12 and older have smoked weed in the past year, compared with 8.9% of people in 2016. Other data show a dip in booze consumption—2023 saw the lowest number of beer sales in the US since 1999, according to an industry report, and wine consumption fell by about 2% in 2022.

Weed is appealing to many folks for more than just the high right now. If you’re one of them, we’re not here to take that away from you. We just want you to know that using cannabis, even if you’re doing that to cut back on drinking, isn’t without its own set of risks for your heart—which is especially important to be aware of when weed is increasingly portrayed as a health-enhancer. Let’s light this conversation up.

Cannabis is associated with serious heart complications—including heart attack and stroke.

“Unlike the potential heart risks associated with smoking cigarettes, which are more broadly understood, I think few people are aware of the potential risks of smoking marijuana,” Ersilia M. DeFilippis, MD, a cardiologist at New York-Presbyterian/Columbia University Irving Medical Center, tells SELF. “Many assume that the drug is harmless, given the increasing legalization of marijuana in states across the country. We should also remember that smoking cigarettes is legal, but we all know that’s bad for us.”

The cannabis flower is filled with between 80 and 100 cannabinoids that affect your body in different ways. Two of the best-known cannabinoids are cannabidiol (CBD), which is a non-psychoactive (and commonly namechecked) cannabinoid that’s often touted for therapeutic benefits; and tetrahydrocannabinol (THC), which is the psychoactive compound of the cannabis plant, meaning it’ll get you high.

These different compounds can have different effects on your system. For example, some limited research indicates that CBD can have positive impacts, decreasing anxiety, helping to mitigate pain, and assisting with sleep. When it comes to your heart, the news is less rosy—and that’s because of THC. A large-scale study of 2,000 folks below 50 who had a heart attack found marijuana users to be two times more likely to suffer from cardiac arrest. Building on this research, a separate large-scale Stanford study tried to answer why. “We found that there is really good evidence that marijuana, and specifically THC, is associated with cardiovascular heart attacks and strokes,” Mark Chandy, MD, PhD, a cardiologist and co-author of the Stanford study, tells SELF.

The authors showed that THC causes inflammation and oxidative stress in the cells lining the blood vessels (endothelial cells), particularly for those who used cannabis more than one time per month. When these kinds of cells are impaired or inflamed, particularly over time, it can result in heart disease, high blood pressure, and hardening of the vessel walls (a.k.a. atherosclerosis). If you think of your system as an intricate set of pipes, atherosclerosis causes clogs, which can result in heart attack and stroke. Following the human results of the trial, the team observed in mice that THC caused atherosclerosis. (It’s worth noting here that the mice study was meant to supplement the trend they observed in humans, and it showed similar outcomes.)

If you’re wondering whether edibles are a better bet than smoking weed…yes, but they still pose a risk to your heart.

They pay me to tell you the bad news, so, straightforwardly: Maybe a little, but they’re still not great for your heart. Whether you’re smoking, vaping, or eating a gummy (or whatever edible you prefer), you’re still going to experience the harmful effects of cannabis on the heart. When I connected with Dr. Springer, he told me that, while we already knew smoke of any kind, including from marijuana and tobacco, caused vascular impairment, the research he did confirmed in human studies that THC itself seems to cause impaired vascular function, too. “The way we interpret all this is that smoke of any sort impairs blood vessel function, and THC also impairs blood vessel function for different reasons,” and through a different pathway, he says.

Given this, you could posit that smoking weed is a double-whammy of impairment, but that edibles only provide a single avenue to potential heart effects, making them a better but not completely risk-averse option. The jury’s still out, but in Dr. Chandy’s view, “It doesn’t matter what form you’re taking with respect to smoking, vaping or taking [THC] in orally, there’s data not just from our paper but from other clinical studies showing that it can cause adverse effects [to the heart].”

Here’s how this all stacks up to booze, heart-health-wise.

It’s a bit of a game of apple (martinis) versus orange (kush) here. Alcohol and weed work very differently in your body. The former works to depress the central nervous system, temporarily putting your brain in chill mode while the liver metabolizes it; the latter conversely activates the endocannabinoid receptors in your brain.

However, we can say with certainty that the more of either thing you use, the more potential for cardiological trouble it comes with. Correlations between increased amounts of either substance are associated with higher risks for your heart. “There is definitely a dose-dependent response,” says Dr. Chandy. In the past few years, leading health organizations have come out against any alcohol use. The World Heart Federation says that for each 100 grams of alcohol per week that you drink (around 12.5 units, or six-ish glasses of wine), you raise your risk of stroke by 14%, heart failure by 9%, and coronary disease by 6%.

At the end of the day (perhaps the kind where you really need a drink?), we’re talking about correlation, not causality. That means that the more you drink or consume THC, the higher the chance either of those things might affect your heart; however, just because you occasionally drink or pop an edible does not definitively mean you’ll absolutely have heart-related issues. Cheers to that?

What about if you only use weed occasionally—that’s probably better, right?

Yeah, it seems like it. According to Dr. Chandy, “[The harm] does seem to be correlated with the amount that’s used.” His team looked at folks who smoked three to five times a week and saw more inflammatory markers or signals that people were likely to have a heart attack when they took THC, and because of this, they believe the potential damage will depend on how often you use it and how potent it is.

That last bit is significant because, as Dr. Chandy says, “In the ’60s and ’70s, the concentration was no more than 3%, and…now you can vape 85% pure THC.”

Dr. DeFilippis says that because recreational marijuana products aren’t regulated, they “vary considerably in dose, concentration and labeling.” Theoretically, lower concentrations of THC in edibles should result in a lower risk of cardiac or vascular issues (though you won’t dodge them altogether). If you’re buying edibles in a state that legally sells them, take note of what the percentage or gram dosage of THC is—it should be on the packaging. On edibles, you’ll see the percentage of THC per serving (in grams) and in the entire container, which allows you to monitor your consumption. In pens or other inhalable options, you’ll find just the percentage of THC that you’ll consume. Again, for your heart, the lower the percentage of THC here, the better.

Here’s the bottom line about what we know about cannabis and heart health so far.

It’s honestly kind of TBD on CBD—but that’s where things look most promising in terms of getting stoned for wellness reasons. CBD seems to have some support for lowering blood pressure through a process called “vasorelaxation,” which has been shown to help relax the arteries of rats, but the jury’s still out since rodents are not, you know, people. Another smaller study seemed to indicate that medical cannabis lowered systolic and diastolic blood pressure in older adults.

In all, we just need more isolated studies for this stuff to be able to say with any authority or assurance—and those are hard to make happen in reality. That’s because marijuana is classified as a Schedule I drug, meaning that there’s a ton of red tape in place in terms of clinically studying it. “When it comes to research, it’s actually very difficult to study, because you have to have special licenses from the DEA, but it definitely merits a lot of investigation,” according to Dr. Chandy.

For now, though, it seems like it’s probably best not to use marijuana if you’re hoping to protect your heart health. “As results have accumulated in the last several years, more and more studies are indicating that using cannabis, including smoking it, increases cardiovascular risk, such as the increased occurrence of heart attacks,” says Dr. Springer.

Unfortunately, while it would be amazing if we could just get high as hell all the time without worry, cannabis isn’t the wellness miracle drug some companies make it out to be as far as your cardiological health is concerned. Even if you don’t see yourself totally cutting out weed, it’s good to know the facts and potentially adjust your intake accordingly. And, while we know it’s not quite the same, there are plenty of other ways to de-stress that won’t also mess with your heart.