Marijuana use raises risk of heart attack, heart failure and stroke, studies say
Older adults who don't smoke tobacco but do use marijuana were at higher risk of both heart attack and stroke when hospitalized, while people who use marijuana daily were 34% more likely to develop heart failure, according to two new non-published studies presented Monday at the American Heart Association Scientific Sessions in Philadelphia.
"Observational data are strongly pointing to the fact that … cannabis use at any point in time, be it recreational or medicinal, may lead to the development of cardiovascular disease," Robert Page II, chair of the volunteer writing group for the 2020 American Heart Association Scientific Statement: Medical Marijuana, Recreational Cannabis, and Cardiovascular Health, said in a statement. He was not involved in either of the new studies.
The AHA recommendations advise people refrain from smoking or vaping any substance, including cannabis products, because of the potential harm to the heart, lungs and blood vessels.
"The latest research about cannabis use indicates that smoking and inhaling cannabis increases concentrations of blood carboxyhemoglobin (carbon monoxide, a poisonous gas), tar (partly burned combustible matter) similar to the effects of inhaling a tobacco cigarette, both of which have been linked to heart muscle disease, chest pain, heart rhythm disturbances, heart attacks and other serious conditions," said Page, a professor in the department of clinical pharmacy and physical medicine/rehabilitation at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences in Aurora, Colorado.
"You need to treat this just like you would any other risk factor (for heart disease and stroke), and honestly understand the risks that you were taking," he said.
A growing problem among older adults
Marijuana use is on the rise among older adults. A 2020 study found the numbers of American seniors over age 65 who now smoke marijuana or use edibles increased two-fold between 2015 and 2018. A 2023 study found past month binge drinking and marijuana use among the over-65 crowd rose by 450% between 2015 and 2019.
Nearly three of every 10 marijuana users develop a dependence on weed called cannabis use disorder. A person is considered dependent on weed when they feel food cravings or a lack of appetite, irritability, restlessness, and mood and sleep difficulties after quitting, according to the National Institute on Drug Abuse.
Marijuana use becomes an addiction when a person is unable to quit using weed even though it interferes with many aspects of life.
Chronic conditions and weed
Older adults often develop a number of chronic conditions by age 65 which appear to make the impact of marijuana worse, according to one of the studies that examined hospital records for adults over 65 with cannabis use disorder who did not smoke tobacco.
"What is unique about our study is that patients who were using tobacco were excluded because cannabis and tobacco are sometimes used together, therefore, we were able to specifically examine cannabis use and cardiovascular outcomes," said lead study author Dr. Avilash Mondal, a resident physician at Nazareth Hospital in Philadelphia, in a statement. Sorry missed that
Researchers found the 8,535 adults who abused weed had a 20% higher risk of having a major heart or brain event while hospitalized, compared to over 10 million older hospitalized adults who did not use marijuana.
Both abusers and non-users had already been diagnosed with high blood pressure, type 2 diabetes or high cholesterol. The study found that having high blood pressure readings of over 130/80 mm Hg and high cholesterol were key predictors of major adverse heart and brain events in the marijuana users.
"We know acute use can lead to a drop in blood pressure and therefore, particularly when this is vaped or when it is smoked and or combusted. And so therefore, that plays into the … understanding the potential risk for stroke," Page said. "But what's interesting is if you look at individuals who've used cannabis daily over very long periods of time, it's actually been associated with an increase in blood pressure which is also a risk factor for numerous other cardiovascular conditions."
Risk of heart failure rose
A second study presented Monday followed nearly 160,000 adults with a median age of 54 for about four years to see if use of cannabis would impact their risk of developing heart failure. Heart failure doesn't mean the heart has stopped working, but that the heart isn't pumping oxygenated blood as well as it should, according to the AHA.
At the end of the study, researchers found people who reported daily marijuana use had a 34% increased risk of developing heart failure, compared to those who reported never using marijuana.
Age, sex at birth and smoking history did not appear to impact the risk. The study researchers did not know if the marijuana was smoked or eaten.
A study published earlier this year also found using marijuana every day can raise a person's risk of coronary artery disease by one third compared with those who never partake. Coronary artery disease is caused by plaque buildup in the walls of the arteries that supply blood to the heart. Also called atherosclerosis, CAD is the most common type of heart disease, according to the US Centers for Disease Control and Prevention.
"Prior research shows links between marijuana use and cardiovascular disease like coronary artery disease, heart failure and atrial fibrillation, which is known to cause heart failure," said Dr. Yakubu Bene-Alhasan, a resident physician at Medstar Health in Baltimore, who was lead author of the heart failure study, in a statement
"Our results should encourage more researchers to study the use of marijuana to better understand its health implications, especially on cardiovascular risk," Bene-Alhasan said.
