Regularly using marijuana can significantly increase a person’s risk of heart attack, heart failure, and stroke, according to a pair of new studies that will be presented at a major upcoming medical conference.
People who use marijuana daily have a 34% increased risk of heart failure, compared with people who don’t use the drug, according to one of the new studies.
The new findings leverage health data from 157,000 people in the National Institutes of Health “All of Us” research program. Researchers analyzed whether marijuana users were more likely to experience heart failure than nonusers over the course of nearly 4 years. The results indicated that coronary artery disease was behind marijuana users’ increased risk. (Coronary artery disease is the buildup of plaque on the walls of the arteries that supply blood to the heart.)
The research was conducted by a team at Medstar Health, a large Maryland health care system that operates 10 hospitals plus hundreds of clinics. The findings will be presented at the American Heart Association’s Scientific Sessions 2023 in Philadelphia.
“Our results should encourage more researchers to study the use of marijuana to better understand its health implications, especially on cardiovascular risk,” said researcher Yakubu Bene-Alhasan, MD, MPH, a doctor at Medstar Health in Baltimore. “We want to provide the population with high-quality information on marijuana use and to help inform policy decisions at the state level, to educate patients, and to guide health care professionals.”
About one in five people in the United States use marijuana, according to the Centers for Disease Control and Prevention. The majority of U.S. states allow marijuana to be used legally for medical purposes, and more than 20 states have legalized recreational marijuana, a tracker from the National Conference of State Legislatures shows.
A second study that will be presented at the conference shows that older people with any combination of type 2 diabetes, high blood pressure, and high cholesterol who use marijuana have an increased risk for a major heart or brain event, compared with people who never used the drug.
The researchers analyzed data for more than 28,000 people age 65 and older who had health conditions that put them at risk for heart problems and whose medical records showed they were marijuana users but not tobacco users. The results showed at least a 20% increased risk of heart attack, stroke, cardiac arrest, or arrhythmia (irregular heartbeat).
The findings are significant because medical professionals have long said that research on the long-term health effects of using marijuana are limited.
“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 Robert L. Page II, PharmD, MSPH, chair of the volunteer writing group for the 2020 American Heart Association Scientific Statement: Medical Marijuana, Recreational Cannabis, and Cardiovascular Health, in a statement. “Together with the results of these two research studies, the cardiovascular risks of cannabis use are becoming clearer and should be carefully considered and monitored by health care professionals and the public.”
A version of this article first appeared on WebMD.com.