Smoking cannabis associated with increased risk of heart attack, stroke

Compared with teens who do not use cannabis, teens who use cannabis are more likely to quit high school or not get a college degree. 2

Cannabis and Teens

The teen years are a time of growth, exploration, and risk-taking. Some risk-taking may foster identity development and independence (e.g., running for student council, asking someone out on a date). However, some risk behaviors—such as using cannabis—can have adverse effects on a teen’s health and well-being.

How many teens use cannabis?

In 2022, 30.7% of US high school 12th graders reported using cannabis in the past year, and 6.3% reported using cannabis daily in the past 30 days. 1 Past-year vaping of cannabis declined from 2020 to 2021 and remained steady in 2022 following large increases in 2018 and 2019. However, many middle and high school students still reported past-year cannabis vaping in 2022—6% of eighth graders, 15% of 10th graders, and 21% of 12th graders. 1

Cannabis and the teen brain

The teen brain is actively developing and continues to develop until around age 25. Cannabis use during adolescence and young adulthood may harm the developing brain. 23

Compared with teens who do not use cannabis, teens who use cannabis are more likely to quit high school or not get a college degree. 2

Negative effects of teen cannabis use

Negative effects include: 2

• Difficulty thinking and problem-solving
• Problems with memory and learning
• Reduced coordination
• Difficulty maintaining attention
• Problems with school and social life

How can cannabis impact a teen’s life:

• Increased risk of mental health issues. Cannabis use has been linked to a range of mental health problems, such as depression and social anxiety. 2 People who use cannabis are more likely to develop temporary psychosis (not knowing what is real, hallucinations, and paranoia) and long-lasting mental disorders, including schizophrenia (a type of mental illness where people might see or hear things that aren’t there). 4 The association between cannabis and schizophrenia is stronger in people who start using cannabis at an earlier age and use cannabis more frequently.
• Impaired driving. Driving while impaired by any substance, including cannabis, is dangerous and illegal. Cannabis negatively affects several skills required for safe driving, such as reaction time, coordination, and concentration. 25
• Potential for addiction. Approximately 3 in 10 people who use cannabis have cannabis use disorder. 6 Some signs and symptoms of cannabis use disorder include trying but failing to quit using cannabis or giving up important activities with friends and family in favor of using cannabis. 7 The risk of developing cannabis use disorder is stronger in people who start using cannabis during youth or adolescence and who use cannabis more frequently.

How can you educate yourself and others?

What teens can do

• Learn the facts about cannabis use so that you can make informed decisions.
• Share information that you learn with friends, parents/guardians, teachers, and others.
• Choose not to drive if you are planning to use, are using, or have used cannabis.

What parents can do

• Talk with your children about the risks of using cannabis while their brains are still developing. Ask your children questions about their cannabis use.
• Know the facts about cannabis. People that begin using cannabis in their teens are more likely to have lasting brain developmental effects and a higher potential for cannabis use disorder.
• Use the resources below to learn more.

Resources

• CDC’s Cannabis and Public Health
• CDC’s Impaired Driving: Get the Facts
• NIDA Drug Facts: Cannabis
• NIDA Cannabis: Facts for Teens

Smoking cannabis associated with increased risk of heart attack, stroke

NIH-funded observational study shows risk grows sharply with more frequent use.

Frequent cannabis smoking may significantly increase a person’s risk for heart attack and stroke, according to an observational study supported by the National Institutes of Health. The study, published in the Journal of the American Heart Association, uses data from nearly 435,000 American adults, and is among the largest ever to explore the relationship between cannabis and cardiovascular events.

The study, funded by the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, found that daily use of cannabis — predominately through smoking — was associated with a 25% increased likelihood of heart attack and a 42% increased likelihood of stroke when compared to non-use of the drug. Less frequent use was also associated with an increased risk of cardiovascular events. Weekly users showed a 3% increased likelihood of heart attack and a 5% increased likelihood of stroke.

Around 75% of the study respondents reported that they mainly used cannabis by smoking the drug. Approximately 25% of the respondents reported using cannabis by some method other than smoking, such as vaping, drinking, or eating the drug.

“We know that toxins are released when cannabis is burned, similar to those found in tobacco smoke,” said corresponding author Abra Jeffers, Ph.D., a data analyst at Massachusetts General Hospital in Boston and formerly a researcher at the Center for Tobacco Control Research and Education at the University of California, San Francisco, where she conducted the study as part of her postdoctoral work.

“We’ve known for a long time that smoking tobacco is linked to heart disease, and this study is evidence that smoking cannabis appears to also be a risk factor for cardiovascular disease, which is the leading cause of death in the United States,” Jeffers said. “Cannabis use could be an important, underappreciated source of heart disease.”

Researchers note that while the exact mechanisms linking cannabis to heart disease are unclear and were not explored in the current study, multiple factors could play a role. In addition to toxins, endocannabinoid receptors — the part of cells responsible for recognizing tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis — are widespread in the body’s cardiovascular tissues and might facilitate heart risks.

Cannabis consumption has increased significantly within the past 20 years nationwide as negative perceptions of its use have declined, according to government surveys of drug use and health. In the United States, cannabis is now legal in 38 states for medicinal use and in 24 states for recreational use. Some studies have linked its regular use to impaired brain development and lung damage, as well as to certain cardiovascular diseases. However, there are gaps in knowledge about the adverse effect of cannabis on the heart.

To look more closely at associations between cannabis use and health, Jeffers and her research team used 2016–2020 data from the Behavioral Risk Factor Surveillance Survey of the Centers for Disease Control and Prevention. The national cross-sectional survey, performed annually by the CDC, included 434,104 adults ages 18-74 from 27 U.S. states and two territories. Most of the respondents were white (60%), while about 12% were Black, 19% Hispanic, and 9% other race/ethnicity.

The researchers evaluated the association of cannabis smoking (the number of days participants said they smoked the drug in the past 30 days) with self-reported cardiovascular outcomes, including coronary heart disease, heart attack, stroke, and a composite measure of all three. They adjusted for the participants’ use of tobacco and other characteristics, including their age, sex, race, body mass index or BMI, obesity, diabetes, physical activity levels, and socioeconomic status.

“This is an important public health finding, particularly given our ongoing efforts to reduce the burden of heart disease in this country,” said David C. Goff, M.D., Ph.D., director of the NHLBI’s Division of Cardiovascular Sciences.

“Asking patients about their cannabis use during routine medical exams or physicals in much the same way they might be asked about tobacco use will help us learn more about the long-term effect of marijuana on the body,” Jeffers said.

he study was funded largely by the NHLBI under grant 1R01HL130484-01A1 and included additional support from National Cancer Institute grant T32 CA113710. For a more complete funding disclosure and list of authors, please see the full JAHA research article.

About the National Heart, Lung, and Blood Institute (NHLBI): NHLBI is the global leader in conducting and supporting research in heart, lung, and blood diseases and sleep disorders that advances scientific knowledge, improves public health, and saves lives. For more information, visit https://www.nhlbi.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

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Study

Jeffers, A, et al. Association of cannabis use with cardiovascular outcomes among US adults Journal of the American Heart Association. DOI: 10.1161/JAHA.123.030178