Updated

For young and middle-aged adults, marijuana use may lead to cardiovascular complications, according to a new study published in the Journal of the American Heart Association.

Using 2006-2010 data from the French Addictovigilance Network, researchers identified 35 cases of cardiovascular and vascular conditions related to the heart, brain and limbs that occurred after marijuana use. They found that most patients were male, with an average age of 34.3 years.

The cases, representing 2 percent of marijuana-related complications,  included 20 heart attacks and nine patient deaths.

According to researchers, marijuana use and related health complications are likely underreported. France has 1.2 million regular marijuana users, and many of the complications may not be recorded by the French Addictovigilance System.

"The general public thinks marijuana is harmless, but information revealing the potential health dangers of marijuana use needs to be disseminated to the public, policymakers and healthcare providers," lead study author Émilie Jouanjus, a medical faculty member at the Centre Hospitalier Universitaire de Toulouse in Toulouse, France, said in a press release.

Researchers noted that people with pre-existing cardiovascular weakness may be more likely to experience the harmful effects of marijuana.

"There is now compelling evidence on the growing risk of marijuana-associated adverse cardiovascular effects, especially in young people," Jouanjus said. "It is therefore important that doctors, including cardiologists, be aware of this, and consider marijuana use as one of the potential causes in patients with cardiovascular disorders."