A recent study has reportedly shown that weed (marijuana) is really bad for your heart.

“The American Heart Association recommends that people not smoke or vape any substance, including cannabis products, because of the potential harm to the heart, lungs and blood vessels,” said Dr. Rose Marie Robertson, the deputy chief science and medical officer for the American Heart Association, in a statement.

Tests showed increases in carbon monoxide and tar in a weed smoker’s blood after smoking — regardless of the THC content. CBD products apparently do not cause the same health issues and are perfectly fine for the heart.

According to the study, weed smoking can trigger heart attacks or strokes. “If people choose to use cannabis for its medicinal or recreational effects, the oral and topical forms, for which doses can be measured, may reduce some of the potential harms,” clinical pharmacologist Robert Page said in a statement.