Marijuana use dramatically increases risk of dying from heart attacks and stroke, large study finds
Get inspired by a weekly roundup on living well, made simple. Sign up for CNN's Life, But Better newsletter for information and tools designed to improve your well-being.
Using marijuana doubles the risk of dying from heart disease, according to a new analysis of pooled medical data involving 200 million people mostly between the ages of 19 and 59.
'What was particularly striking was that the concerned patients hospitalized for these disorders were young (and thus, not likely to have their clinical features due to tobacco smoking) and with no history of cardiovascular disorder or cardiovascular risk factors,' said senior author Émilie Jouanjus, an associate professor of pharmacology at the University of Toulouse, France, in an email.
Compared to nonusers, those who used cannabis also had a 29% higher risk for heart attacks and a 20% higher risk for stroke, according to the study published Tuesday in the journal Heart.
'This is one of the largest studies to date on the connection between marijuana and heart disease, and it raises serious questions about the assumption that cannabis imposes little cardiovascular risk,' said pediatrician Dr. Lynn Silver, a clinical professor of epidemiology and biostatistics at University of California, San Francisco.
'Getting this right is critically important because cardiovascular disease is the top cause of death both in the United States and globally,' said Silver, who is also senior adviser at the Public Health Institute, a nonprofit public health organization that analyzes marijuana policy and legalization.
Silver is the coauthor of an editorial published with the paper that calls for change in how cannabis is viewed by health professionals, regulatory bodies and the public at large.
'Clinicians need to screen people for cannabis use and educate them about its harms, the same way we do for tobacco, because in some population groups it's being used more widely than tobacco,' she said. 'Our regulatory system, which has been almost entirely focused on creating legal infrastructure and licensing legal, for-profit (cannabis) businesses, needs to focus much more strongly on health warnings that educate people about the real risks.'
The new systematic review and meta-analysis analyzed medical information from large, observational studies conducted in Australia, Egypt, Canada, France, Sweden and the US between 2016 and 2023.
Those studies did not ask people how they used cannabis — such as via smoking, vaping, dabbing, edibles, tinctures or topicals. (Dabbing involves vaporizing concentrated cannabis and inhaling the vapor.) However, 'based on epidemiological data, it is likely that cannabis was smoked in the vast majority of cases,' Jouanjus said.
Smoking tobacco is a well-known cause of heart disease — both the smoke and the chemicals in tobacco damage blood vessels and increase clotting, according to the US Centers for Disease Control and Prevention.
Therefore, it is not surprising that smoking, vaping or dabbing cannabis could do the same, Silver said: 'Any of the many ways of inhaling cannabis are going to have risks to the user, and there's also secondhand smoke risks, which are similar to tobacco.'
The notion that smoking cannabis is less harmful because it's 'natural' is just wrong, Dr. Beth Cohen, professor of medicine at the University of California, San Francisco, told CNN in a prior interview.
'When you burn something, whether it is tobacco or cannabis, it creates toxic compounds, carcinogens, and particulate matter that are harmful to health,' Cohen said in an email.
However, edibles may also play a role in heart disease, according to a May 2025 study.
People who consumed edibles laced with tetrahydrocannabinol, or THC, showed signs of early cardiovascular disease similar to tobacco smokers.
'We found that vascular function was reduced by 42% in marijuana smokers and by 56% in THC-edible users compared to nonusers,' Dr. Leila Mohammadi, an assistant researcher in cardiology at the University of California, San Francisco, told CNN in a prior interview.
None of the studies included in the new meta-analysis asked users about the potency of THC in the products they consume. Even if they had, that information would be quickly outdated, Silver said.
'The cannabis market is a moving target. It is getting more potent every day,' she said.
'What's being sold to people today in California is 510 times stronger than what it was in the 1970s. Concentrates can be 99% pure THC. Vapes are over 80% THC.
'A variety of chemically extracted cannabinoids can be almost pure THC, and all of these just have very different effects on people than smoking a joint in the 1970s.'
Higher potency weed is contributing to a host of problems, including an increase in addiction — a July 2022 study found consuming high-potency weed was linked to a fourfold increased risk of dependence.
In the United States, about 3 in 10 people who use marijuana have cannabis use disorder, the medical term for marijuana addiction, according to the CDC.
'We know that more potent cannabis makes people more likely to become addicted,' Silver said. 'We know that more potent cannabis makes people more likely to develop psychosis, seeing and hearing things that aren't there, or schizophrenia. Habitual users may also suffer from uncontrollable vomiting.'
The rise in potency is one reason that the current study may not have captured the full extent of the risk of marijuana for heart disease, Jouanjus said: 'We are afraid that the association might be even stronger than that reported.'
While science continues to study the risk, experts say it's time to think twice about the potential harms of cannabis use — especially if heart disease is a concern.
'If I was a 60-year-old person who had some heart disease risk, I would be very cautious about using cannabis,' Silver said. 'I've seen older people who are using cannabis for pain or for sleep, some of whom have significant cardiovascular risk, or who have had strokes or had heart attacks or had angina, and they have no awareness that this may be putting them at greater risk.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Digital Trends
33 minutes ago
- Digital Trends
SpaceX reveals new target date for private crewed launch to ISS
SpaceX, partnering with NASA and Axiom Space, is aiming to blast a four-person crew to orbit at 3:42 a.m. ET on Sunday, June 22. The private Ax-4 mission was supposed to launch to the International Space Station (ISS) from Florida's Kennedy Space Center on June 10, but inclement weather in the ascent corridor forced the mission team to call off the effort. A plan to launch 24 hours later was also ditched following the discovery of a liquid oxygen leak on the rocket. Recommended Videos NASA has also been monitoring an air leak in the Russian Zvezda service module at the space station, an additional situation that prompted NASA, in coordination with its Russian counterpart Roscosmos, to delay the Ax-4 launch for safety reasons while they worked out what to do. Following repairs, pressure in the affected area stabilized, and NASA was able to announce a new target launch date. After patiently waiting in isolation at the Kennedy Space Center, the four crewmembers are now setting their sights on this Sunday, hoping that their long-awaited orbital adventure can finally begin. 'The change in a targeted launch date provides NASA time to continue evaluating space station operations after recent repair work in the aft (back) most segment of the International Space Station's Zvezda service module,' Axiom Space said in a release. Peggy Whitson, a former NASA astronaut and now director of human spaceflight at Axiom Space, will command the commercial mission. Flying with her in a SpaceX Crew Dragon capsule will be individuals from India, Poland, and Hungary, with each nation on the cusp of celebrating its first-ever mission to the space station. The mission will last about two weeks, with the four members living and working alongside the current ISS crew. Interested in watching SpaceX's first crewed launch since Crew-10's flight in March? Digital Trends has everything you need to know.
Washington Post
35 minutes ago
- Washington Post
A judge could advance Purdue Pharma's $7B opioid settlement after all 50 states back it
All 50 U.S. states have agreed to the OxyContin maker Purdue Pharma 's latest plan to settle thousands of lawsuits over the toll of opioids . A judge on Wednesday is being asked to clear the way for local governments and individual victims to vote on it. Government entities, emergency room doctors, insurers, families of children born into withdrawal from the powerful prescription painkiller, individual victims and their families and others would have until Sept. 30 to vote on whether to accept the deal, which calls for members of the Sackler family who own the company to pay up to $7 billion over 15 years.
Yahoo
an hour ago
- Yahoo
Something in Your Poop May Predict an Imminent Death
The contents of a patient's entrails could be key to assessing how close they are to death. No, it's not some form of living haruspicy. A team of doctors led by Alexander de Porto of the University of Chicago and the University of Amsterdam has created an index of markers in a patient's feces that can help gauge the risk of mortality within 30 days. They have named it the metabolic dysbiosis score (MDS), and it could help save the lives of critically ill patients in medical intensive care. Their results, they caution, require further investigation and validation, but offer exciting promise as a future tool for diagnostic medicine. "The findings suggest that fecal metabolic dysbiosis, quantified through the MDS, holds potential as a biomarker to identify critically ill patients at increased risk of mortality," de Porto and his colleagues, Eric Pamer and Bhakti Patel of the University of Chicago, told ScienceAlert. "This underscores the importance of gut-derived metabolites as independent contributors to host resilience, offering an avenue for precision medicine." Critically ill patients admitted to intensive care units often develop severe syndromes such as sepsis and acute respiratory distress – but these syndromes don't always develop and evolve in the same way. This heterogeneity poses a huge challenge for trying to treat these patients; two patients with the same syndrome may respond to the same treatment very differently. One way to circumvent this challenge, the researchers said, is to identify specific traits to treat rather than attacking the whole syndrome at once. Scientists know that critically ill patients often have reduced diversity in their gut microbiota, as well as altered concentrations of the metabolites produced by their microbiomes. De Porto and his colleagues embarked on an investigation into dysbiosis, an imbalance in the gut microbiome, in critically ill patients, as a trait that could be treated. They studied fecal samples collected from 196 patients exhibiting respiratory failure or shock, dividing them into a training cohort of 147 patients and a validation cohort of 49 patients. They used these samples to develop the MDS, based on concentrations of 13 distinct fecal metabolites. The results indicate an auspicious avenue for further investigation. "The MDS performed well in predicting mortality in the training cohort of medical ICU patients, with 84 percent accuracy, 89 percent sensitivity, and 71 percent specificity," the researchers said. "However, the validation cohort, despite showing similar trends, failed to reach statistical significance, probably due to its smaller sample size. These findings highlight the promise of the MDS but also underscore the necessity to validate its predictive capacity and generalizability in independent cohorts before widespread application." What the researchers found particularly interesting is that, even though a lack of diversity in the microbiome has previously been associated with adverse outcomes in critically ill patients, they could find no such link. Instead, their results showed a strong link between dysbiosis and increased mortality risk, suggesting that an imbalance in the microbiome plays a crucial role in patient health. A lot more work needs to be done before the team's approach is suitable for clinical application. The null result in the validation cohort of just 47 patients shows that quite a bit of refinement is required. However, there are several encouraging points. The lab has shown, for instance, that fecal metabolites can identify liver transplant patients who have a higher risk of developing a post-operative infection. In addition, while specific treatments have not yet been investigated or identified, the MDS indicates some pathways for further exploration. "The metabolites comprising the score, such as short-chain fatty acids, bile acids, and tryptophan metabolites, point to biological pathways that might be targeted therapeutically," the researchers said. "Potential interventions might include dietary changes, administration of probiotics, or direct supplementation with these metabolites." The next step is to work on validating MDS in new sets of patients, and to examine whether the link between the observed dysbioses and the increased mortality risk is causal or symptomatic of another cause. "Subsequently," the researchers said, "intervention trials targeting specific metabolites or metabolic pathways are necessary to assess therapeutic benefits." The research has been published in Science Advances. Long-Term Contraceptive Pill Use Linked With Brain Tumor Risk Just One Night of Poor Sleep Can Change How Your Brain Sees Food Insulin Isn't Just Made by The Pancreas. Here's Another Location Few Know About.
