A sign of the increasing acceptance of marijuana is the growing number of facilities dispensing medical marijuana in Los Angeles. Those who frequent these dispensaries often tout the drug’s benign side effects, asserting that long-term marijuana use has no lasting impact on an individual’s health. However, a number of studies report that the habit is indeed harmful to one’s health. Recent studies have reported that marijuana use in the teens lowers IQ; however, a new study by researchers affiliated with the University of Auckland in New Zealand reported a much more serious health hazard: an increased risk of stroke. They presented their findings at the International Stroke conference 2013, which runs from February 6 through February 8 in Honolulu, Hawaii.
The researchers found that marijuana may double the risk of ischemic stroke and transient ischemic attack (TIA) in young adults, including individuals who had no risk factors for one of these cardiovascular events. The study’s lead author, Dr. P. Alan Barber, a professor of clinical neurology at the University of Auckland, noted that he became interested in studying a link between stroke and marijuana after some of his younger patients suffered a stroke. The patients were young and did not have any stroke risk factors such as high blood pressure, elevated blood pressure, or any indicators of poor health. However, they suffered a stroke while smoking marijuana.
The researchers conducted what they describe as the first case-controlled study of its kind. The study group comprised 160 ischemic stroke/TIA patients between the ages of 18 to 55 (average age: 45); they all had their urine samples screened when they entered the hospital. For a control group, the investigators examined urine samples of 160 control subjects who had been admitted to the hospital for other medical reasons. Of the 160 stroke patients, 16% tested positive for marijuana use within the past couple of days, compared to only 8.1% of the control group. The stroke patients were matched to the controls and had no differences in age, mechanisms for stroke, or other vascular risk factors. Despite the link between marijuana and a stroke or TIA, the researchers found one confounding factor: almost all of the 16% of stroke patients who were marijuana users, almost all of them smoked tobacco regularly; thus, the increased risk might be due to a combination of exposure to cannabis and tobacco smoke. Another limitation of the study was that the urine samples for the control subjects were obtained without the patients’ consent; therefore, the researchers only knew their age, sex, and ethnicity.
The researchers note that further research is needed to clarify the relationship between marijuana and stroke. Complicating this research is the fact that a joint may carry varying amounts of cannabis and may contain other drugs, which could increase stroke risk.
According to the Centers for Disease Control and Prevention (CDC), stroke is one of the leading causes of death in the United States, killing close to 130,000 Americans each year. Most individuals who experience a stroke are over the age of 65; thus, this study of stroke among young adults is extremely disturbing.