Weed may do way more damage to your heart than we thought

• Two new studies suggests marijuana use can be harmful for heart health.
• Using marijuana may increase risk of issues like heart attack or stroke in frequent or older users.

Smoking pot, taking edibles, or unwinding with a cannabis-infused beverage have become increasing popular as more states have eased up on laws restricting recreational use.

But a marijuana habit isn't risk-free, new research suggests.

Regular marijuana use is linked to significantly higher risk of cardiovascular issues like heart attack or stroke, according to a pair of preliminary studies to be presented at the American Heart Association (AHA) 2023 Scientific Sessions.

The findings suggest that marijuana may be more concerning for health than people suspect, particularly for frequent consumers and those with underlying health conditions.

Using marijuana every day may increase risk of heart failure

In one study, researchers at Medstar Health in Baltimore looked at data from 156,999 people, who were initially free from heart failure, over four years of follow up to compare health outcomes with self-reported marijuana use.

They found that people who used marijuana daily had a 34% higher risk of developing heart failure than people who never used marijuana.

The study defined marijuana use as any consumption that was not prescribed for a health condition.

The findings suggest that more evidence on how marijuana affects health could help consumers and health professionals make more informed decisions, according to Dr. Yakubu Bene-Alhasan, lead author of the study and a physician at Medstar.

"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 in a the press release.

Marijuana might worsen health issues in older adults

Another study, from a separate group of researchers from multiple institutions, including Bahria University in Pakistan and Adelphi University in New York, looked at the hospitalization records from more than 10 million adults over age 65. The participants didn't smoke tobacco and had existing health issues like high blood pressure, high cholesterol, or type 2 diabetes.

The researchers wanted to see whether marijuana use, reported in more than 28,000 of the patients, played a role in complications during hospital stays.

They found that patients with marijuana use disorder, often described as a dependency on the drug, were significantly more likely to have a major cardiac or brain event, like a heart attack or stroke.

The study was unique in that is ruled out tobacco use as a possible factor — cannabis on the rise in older adults, according to Dr. Avilash Mondal, lead study author and physician at Nazareth Hospital in Philadelphia.

"At this point, we need more studies to understand the long-term effects of cannabis use," Mondal said in a press release. "Health care professionals should include the question, 'Are you using cannabis?' when taking a patient's history. If you ask patients if they are smoking, people think cigarette smoking. The main public message is to be more aware of the increased risks and open the lines of communication so that cannabis use is acknowledged and considered."

A limitation of the study is that is it relied on a large database from multiple hospitals, and health records on cannabis use disorder may have varied between institutions. Cannabis use disorder is typically defined by factors like using the drug more than intended despite negative consequences, and having difficulty cutting back.

The long-term health effects of cannabis aren't yet clear

Along with evidence that smoking cannabis has similar risks as cigarette use, the findings warrant more caution around cannabis use and heart health, according to Robert L. Page II, professor of clinical pharmacy at the University of Colorado and chair of the volunteer writing group for the 2020 American Heart Association Scientific Statement: Medical Marijuana, Recreational Cannabis, and Cardiovascular Health.

Page, who was not involved with either study, said that inhaling cannabis smoke increases blood concentrations of carbon monoxide, a toxic gas, as well as tar, both of which are linked to serious heart problems.

"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," he said.

Previous evidence also suggests that while other forms of cannabis use — like consuming edibles — may avoid some exposure to the toxins involves in smoking, they can still have negative effects on heart health. That's because THC, the active ingredient in marijuana that gets you high, may be harmful to the heart.

While more studies are needed to better understand how cannabis affects heart health, people who chose to use it should be aware of the risks, according to Page.

"When I interact with patients, they always tell me, 'Well, it's natural, so it must be safe.' Well, that's very far from the truth," he said in the press release.