The researchers say that their findings indicate that marijuana use is a greater risk factor for poor cardiovascular health than cigarette smoking.
Lead study author Barbara A. Yankey, of the School of Public Health at Georgia State University in Atlanta, and her team recently reported their results in the European Journal of Preventive Cardiology.
Around 75 million people in the United States - or 32 percent of the U.S. population - have high blood pressure.
Cigarette smoking is a well-established risk factor for high blood pressure and poor cardiovascular health, but according to the new study from Yankey and team, marijuana use may be even more harmful.
Death from hypertension increased threefold
The researchers came to their findings by analyzing the data of 1,213 adults aged 20 and older, all of whom had participated in the 2005-2006 National Health and Nutrition Examination Survey.
As part of the survey, subjects were asked whether they had ever used marijuana, and if so, the age at which they first used the drug. Information on cigarette use was also collected.
In order to calculate the duration of marijuana use among participants, the researchers subtracted the age at first marijuana use from subjects' current age.
Using 2011 data from the National Center for Health Statistics, the researchers assessed whether or not marijuana use might influence the risk of death from hypertension, heart disease, and cerebrovascular disease.
Overall, 21 percent of the participants reported using marijuana, 20 percent used marijuana and cigarettes, 16 percent used marijuana and were past-users of cigarettes, 5 percent had smoked in the past, 4 percent used cigarettes only, and 34 percent had never used marijuana or cigarettes.
The average duration of marijuana use among users of the drug was 11.5 years.
Compared with subjects who had never used marijuana, the results revealed that marijuana users were 3.42 times more likely to die from high blood pressure. For each year of marijuana use, the risk of death from hypertension increased by 1.04 times.
No link was found between the use of marijuana and the risk of death from heart disease and cerebrovascular disease, the team reports.
Marijuana vs. smoking
The researchers note that their findings also suggest that marijuana use may be a greater risk factor for poor cardiovascular health than smoking cigarettes.
"We found higher estimated cardiovascular risks associated with marijuana use than cigarette smoking," says Yankey. "This indicates that marijuana use may carry even heavier consequences on the cardiovascular system than that already established for cigarette smoking."
"However, the number of smokers in our study was small and this needs to be examined in a larger study," she adds. "Needless to say, the detrimental effects of marijuana on brain function far exceed that of cigarette smoking."
While the study was not designed to investigate the mechanisms underlying the link between marijuana use and hypertension-related mortality, the researchers note that the drug is known to affect the cardiovascular system in a number of ways.
"Marijuana stimulates the sympathetic nervous system, leading to increases in heart rate, blood pressure, and oxygen demand," explains Yankey. "Emergency rooms have reported cases of angina and heart attacks after marijuana use."
Given the increasing U.S. legalization of marijuana for recreational purposes, medicinal purposes, or both, Yankey and colleagues say that it is important to get a better understanding of how the drug impacts health.
"Support for liberal marijuana use is partly due to claims that it is beneficial and possibly not harmful to health," says Yankey.
"With the impending increase in recreational marijuana use it is important to establish whether any health benefits outweigh the potential health, social, and economic risks. If marijuana use is implicated in cardiovascular diseases and deaths, then it rests on the health community and policy makers to protect the public."