(Family Features) Legalization of marijuana for medical and recreational use is increasing across the United States. However, according to two scientific studies published by the American Heart Association, marijuana may increase the risk for deadly cardiovascular diseases, heart attacks, and strokes.

The scientific statement “Medical Marijuana, Recreational Cannabis and Cardiovascular Health,” says marijuana may be helpful for some medical conditions, but doesn’t appear to have well-documented benefits for preventing or treating cardiovascular diseases (CVD). The chemicals in cannabis have also been linked to an increased risk of heart attacks, heart failure, and atrial fibrillation. One Stanford University study found that people who used marijuana daily were 34% more likely to be diagnosed with coronary heart disease than those who did not. Marijuana users may also have an increased risk of clot-caused stroke, according to the scientific statement, “Use of Marijuana: Effect on Brain Health.” Both studies found that marijuana users had from 17% to 24% more strokes, compared to those who do not use marijuana.

“There is a lot of confusion about the benefits versus the dangers of marijuana use, and much of that depends on the ingredients in and the method of use of the product,” says Robert L. Page II, Pharm.D., M.S.P.H., FAHA, volunteer chair of the writing group for the statement on medical and recreational marijuana and cardiovascular disease. “The most common chemicals in cannabis include THC, or tetrahydrocannabinolic acid, the psychoactive component of the plant that induces a ‘high,’ and CBD, or cannabidiol, which can be purchased over the counter. These chemicals may be working at cross purposes, as some studies suggest that CBD could reduce heart rate and blood pressure, while THC may raise heart rate and blood pressure.”

Smoking and inhaling marijuana, regardless of THC content, has been associated with heart muscle dysfunction, chest pain, heart attacks, heart rhythm disturbances, sudden cardiac death, and other serious cardiovascular conditions. It has also been shown to increase the concentrations of poisonous carbon monoxide and tar in the blood, similar to the effects of inhaling a tobacco cigarette,” says Page. He says, “The federal government classifies marijuana as a Schedule 1 drug ‘with no currently accepted medical use and a high potential for abuse.’ This means researchers face tight restrictions on conducting controlled trials with marijuana products. So much of what we know about cannabis use is based on data from short-term, observational, and retrospective studies, which identify trends, but do not prove cause and effect. Until we know the pros and cons of marijuana use, people need to be aware of the potential dangers.”

Page recommends that people who use marijuana, for medicinal or recreational reasons, use only legal cannabis products, due to the lack of control of content in products sold on the street. Additionally, doses can be measured in cannabis in oral and topical forms, possibly reducing potential harm. Finally, Page says it is important for people to be open with their doctors about using marijuana, as it may interfere with their prescribed medications or possibly trigger cardiovascular conditions or events. Learn more at www.heart.org