Marijuana Smoke Is More Harmful In The Short Term Than Previously Thought

Secondhand marijuana smoke is more harmful in the short term than previously thought according to a new study published in the Journal of the American Heart Association. The study discovered that secondhand marijuana smoke has a more detrimental effect on human arteries than secondhand cigarette smoke. This study is the first to find that marijuana smoke is worse than tobacco smoke. In all previous studies, the reverse was found to be true.

The marijuana secondhand smoke study was performed at the University of California – San Francisco’s Division of Cardiology. The researchers at the university performed their experiments on lab rats. The scientists checked the blood vessel function of the rats before and after they were subjected to marijuana smoke for exactly one minute. What the researchers discovered was that breathing in the marijuana smoke for just one minute compromised how the rats’ arteries performed for more than an hour and a half. The researchers noted that that is over three times what the rats’ arteries took to recover after breathing conventional tobacco smoke for the same amount of time.

secondhand smoke [Photo by David Ramos/Getty Images]The senior author of the study at the University of California – San Francisco’s Division of Cardiology, Mathew Springer, commented on the findings.

“While the effect is temporary for both cigarette and marijuana smoke, these temporary problems can turn into long-term problems if exposures occur often enough and may increase the chances of developing hardened and clogged arteries.There is widespread belief that, unlike tobacco smoke, marijuana smoke is benign. We in public health have been telling the public to avoid secondhand tobacco smoke for years, but we don’t tell them to avoid secondhand marijuana smoke, because until now we haven’t had evidence that it can be harmful.”

The scientists that conducted the marijuana study stated that the compromised artery and blood vessel performance as a result of inhaling marijuana smoke wasn’t the result of the plant’s active agent, THC — or tetrahydrocannabinol — just as it is not a result of nicotine in cigarettes. Instead, the smoke itself is the primary reason for the harmful effects to the body. To prove this, in the experiment, the researchers removed the THC from marijuana smoke. Additionally,the university researchers eliminated the paper in which the marijuana was rolled in to make sure that it wasn’t the smoke from the paper that was causing the reduced artery and blood vessel performance.

The university researchers also stressed that rat and human arteries respond extremely similarly to the effects of secondhand tobacco smoke, so it is very likely that human arteries will also respond similarly to secondhand marijuana smoke.

secondhand smoke [Photo by Bruce Bennett/Getty Images]This latest study seems to fly in the face of previous information about marijuana smoke and its effects on the body. In 2014, a study found that serious heart problems rarely occur immediately following the use of marijuana. Another research study found that a marijuana smoker’s risk of heart attack within an hour was five times greater compared to people who didn’t smoke marijuana. In contrast, this is actually a very small risk when compared to an especially strenuous session of exercise. Yet another study found an increased risk of death among patients who already suffered an earlier heart attack and who regularly smoked marijuana.

However, all of the studies mentioned, including the latest one, are all short term. Longer term studies have yet to be limited, and even fewer studies have been don on secondhand marijuana smoke. Stranger yet, there are other studies that have suggested that the inhaling of marijuana smoke can temporarily increase the risk of artery and cardiovascular issues, while at the same time the THC in the marijuana smoke can actually slow the development of the narrowing and hardening of the arteries — a condition known as atherosclerosis.

Clearly, more long term studies need to be performed so that marijuana smokers can get a clearer picture of what marijuana is doing to their bodies.

[Feature Photo by David Ramos/Getty Images]