A new study claims marijuana users have three times greater risk of dying from hypertension than those who never used the drug. The researchers also said the risk grows with every year of marijuana use.

The retrospective study involved over 1,200 people who had been asked years ago if they had used marijuana. The research was carried by scientists at the school of public health at Georgia State University.

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It’s important to highlight that, just like any other study, this one had some limitations. For instance, the researchers defined marijuana users as anyone who’s ever tried it. The findings were published Wednesday in the European Journal of Preventive Cardiology.

Marijuana users increase risk of hypertension by 1.04 with each year of use

Barbara Yankey, the co-author of the research, noted that support for liberal marijuana use is partly due to claims that the drug is beneficial and possibly not harmful to health.

“It is important to establish whether any health benefits outweigh the potential health, social and economic risks,” added Yankey, according to Reuters. “If marijuana use is implicated in cardiovascular diseases and deaths, then it rests on the health community and policy makers to protect the public.”

In the study, Yankey and her colleagues looked at more than 1,200 people age 20 or older who had been surveyed previously as part of a larger and ongoing national health survey. The participants had been asked in 2005 whether they had ever tried marijuana or hashish. Those who answered “yes” were labeled as marijuana users, while people who answered “no” were classified as nonusers.

The researchers merged that information with statistics on death from all causes, taken from the U.S. National Center for Health Statistics, and adjusted the data to rule out any factors that could tamper the results, such as race, gender, and history of smoking tobacco.

Afterward, they analyzed the resulting data and found marijuana users were 3.42 times as likely to die from hypertension or high blood pressure than nonusers. The risk also seemed to rise 1.04 for each year of use.

“Steps are being taken towards legalization and decriminalization of marijuana in the United States, and rates of recreational marijuana use may increase substantially as a result,” Yankey said in a press release. “However, there is little research on the impact of marijuana use on cardiovascular and cerebrovascular mortality.”

Study didn’t take into account the up to 400 strains of marijuana on the market

One of the study’s limitations is that the authors defined anyone who said they had tried marijuana as a “regular user.” However, it is clear that a “regular user” should be described as a person who regularly uses marijuana, not an individual who tried it at least once. A recent survey found that 52 percent of Americans have tried marijuana at some point in their lives, but only 14 percent reported using the drug “regularly,” which was defined as at least once a month.

Another limitation was that the study was observational, as it only looked at a group of people over a period and reported what happened to them. Meaning, the authors can’t say with absolute certainty that smoking marijuana caused hypertension on the participants, as they didn’t conduct any medical examination on them.

Image credit: AP / Damian Dovarganes / Business Insider
Despite its medicinal traits, smoking marijuana could be deadly to some extent. Image credit: AP / Damian Dovarganes / Business Insider

Some experts also noted that there are hundreds of marijuana strains, all of which could have different effects on the human body. As marijuana is still illegal at the federal level –even in the states where it is legalized either for medicinal or recreational purposes– there is a large, unregulated cannabis market in the United States.

There are about 400 different strains and compounds of marijuana, including CBD and THC. Charles Pollack, the director of the Lambert Center for the Study of Medicinal Cannabis, who was not involved in the new study, told Live Science there are many strains of marijuana with “no quality standards,” and that made it tough to generalize the effects.

Marijuana or alcohol at moderate levels can be ‘kind of positive.’

Dr. Kenneth Alan Jamerson, from the University of Michigan, told TCTMD that while the U.S. National Center for Health Statistics database is important, its data regarding illicit drug use might not be as reliable, as health professionals collected it at participant’s homes. He explained that if you come to somebody’s home and ask them about marijuana usage, you’re not going to get the greatest data, and said that’s a limitation.

Furthermore, he added that while the findings are worthwhile, they don’t show that marijuana is harmful. Jamerson said that recreational use of drugs like marijuana and alcohol at moderate levels had been shown to be “kind of positive.”

Jamerson also said that is unusual that the researchers only reported data for mortality associated with hypertension and not with cerebrovascular or heart disease.

“You would think that the marijuana if it was working on the vascular system to cause some damage, it should cause stroke, it should cause heart disease; it shouldn’t [only] cause hypertension,” he told TCTMD. “And you wouldn’t understand in this particular setting why the effect of marijuana was more than cigarettes when we know clearly that cigarettes have an effect.”

Source: Business Insider