Marijuana cultivation and use dates back some 6,000 years. However, the cardiovascular and other health effects of cannabis aren’t well studied. That’s partly because under federal law, cannabis is a Schedule I substance, meaning it has “no currently accepted medical use and a high potential for abuse.” That designation places numerous restrictions on researchers, making it difficult to carry out rigorous research on marijuana.
“As a result, everything we’re told about what marijuana does or doesn’t do should be viewed with a certain amount of caution. This holds equally true for the risks as well as the benefits,” says Dr. Kenneth Mukamal, associate professor of medicine at Harvard-affiliated Beth Israel Deaconess Medical Center.
There have been a few studies to suggest that marijuana use could have a negative effect on a person’s heart health. However, some studies say there’s no evidence to that claim.
Researchers from California, Pennsylvania and New York examined dozens of studies that claimed that marijuana use had a negative effect on a person’s heart health. They determined that most of these studies were highly flawed and that the evidence the presented was “insufficient.”
The most notable study they documented was one that came out last August that said marijuana users were three times more likely to die from hypertension than non-users. But what the study didn’t note was that their definition of a “marijuana user” was anyone who had used the drug at least once in their entire lifetime. So a person who smoked one joint at 18 and then never again the rest of their life was considered a marijuana user for the purpose of the study. That’s just too broad a definition.
There are a few things we do know about marijuana use and the heart. We do know that using cannabis raises a person’s heart beats per minute for up to three hours after consumption, although it’s not known if this is harmful to the user’s health. It’s also pretty well-documented that marijuana use lowers blood pressure, as studies have shown that as well as others that showed people who stopped using cannabis often saw their blood pressure increase after quitting.
To put it simply, almost any previous study that claims marijuana negatively affects heart health is highly flawed and should be taken with a grain of salt. That doesn’t necessarily mean that cannabis use is good for your heart, either. But there are definitely other things to avoid putting in your body that take precedence over marijuana.
Researchers published a study just earlier this year on long term users. That study followed more than 5,000 people for 25 years. The authors of that study wrote,
Compared with no marijuana use, cumulative lifetime and recent marijuana use showed no association with incident CVD [cardiovascular disease], stroke, or transient ischemic attacks, coronary heart disease, or CVD mortality.
A study last year, tracking 38 years of use also came to the same conclusion. A leading expert on study design and results, Dr. Vinay Prasad, associate professor of medicine at Oregon Health & Science University commented on Yankey’s work. In an email reply to The Oregonian, he stated,
It does not prove that if you choose to use marijuana you are more likely to die of cardiovascular disease. I think the major limit of the study is that there may be unobserved differences between the people who used and admitted to using marijuana during the years of this study, and cardiovascular outcomes that the researchers did not adjust for. In fact, that is likely.
In reality, when looking at studies that try to disparage cannabis as a positive medicine, take their findings with a dash of salt. Oh, wait, that’s something else they forgot to take into account. True, cannabis increases heart rate, for a short time, and like exercise should be consulted about with a doctor if you have heart issues.