A new study has reported that cannabis smokers are more than three times as likely to die from hypertension than those who don't smoke pot. The study, published in the European Journal of Preventive Cardiology, looked at around 1,200 Americans who took the National Health and Nutrition Examination Survey in 2005. These respondents answered a number of health-related questions, including questions about their cannabis use, and underwent a physical examination.
The researchers compared the results of this survey to 2011 mortality data for the same group of people. The results of this comparison found that those who admitted to smoking pot had a 3.2 times greater death risk from hypertension. This risk was found to increase by 1.04 times for every year the individual continued to smoke cannabis.
"Support for liberal marijuana use is partly due to claims that it is beneficial and possibly not harmful to health," said lead author Barbara Yankey. “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."
While the results of the study are alarming, they are not necessarily conclusive. Yankey noted in the study that it was assumed that those who admitted smoking pot in 2005 continued smoking pot regularly until 2011, which may not have been the case. And while the study did control for cigarette smoking and previous diagnoses for high blood pressure, it did not control for other cardiovascular risk factors, such as diet and exercise.
The study “does not prove that if you choose to use marijuana you are more likely to die of cardiovascular disease," said Dr. Vinay Prasad, associate professor of medicine at Oregon Health & Science University. "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."
Further research will be needed to confirm whether or not cannabis use is in fact responsible for an increased death risk from high blood pressure. Yankey recommends that researchers undertake “purposeful designed follow-up studies to assess the relationship between marijuana use and cardiovascular mortality.”