Marijuana and Stroke, May be Dangerous to Toke
Marijuana users may want to take notice of a potential health hazard related to their drug use: stroke. According to a new study, middle aged people who use marijuana are more likely to experience a stroke than their peers who don’t indulge. Previous research also suggests it may be dangerous to toke among even younger people.
Are young marijuana smokers at risk for stroke?
Stroke most often affects older people. In fact, 75% of strokes occur in people age 65 and older. That means 25 percent of the 795,000 strokes that occur each year in the United States are among younger people.
The most common type of stroke is ischemic, which basically means a blood clot blocks the flow of blood to the brain. The underlying condition contributing to this blockage is atherosclerosis, or fatty deposits accumulating in the blood vessels.
Other factors also may be involved in ischemic stroke, however, especially in younger people who often have stroke due to other causes. One of them may be marijuana use.
Although there may be a number of medical reasons to use marijuana, such as pain reduction, help with Crohn’s disease, and perhaps even type 2 diabetes, there can be downsides, as there are with drugs in general.
Results of the new study from the University of Auckland (UA) in New Zealand were presented at the International Stroke Conference. To arrive at their findings, the researchers evaluated 160 patients (age range 18 to 55) who had suffered a stroke (94% of participants) or a transient ischemic attack (TIA). Controls were 160 adult patients with no history of stroke.
Urine tests were used to identify the presence of marijuana. The researchers discovered that 16% of stroke patients were positive for marijuana use compared with 8% of controls. After researchers made adjustments for factors such as age, sex, and ethnicity, the only factor associated with the 2.3 increased risk of stroke or TIA they found was marijuana use.
According to P. Alan Barber, MD, PhD, professor of clinical neurology at UA, their finding “provides the strongest evidence to date” of a relationship between marijuana and stroke. It is not the only study, however, that has linked marijuana use with stroke.
In the December 2012 issue of Stroke, investigators from Cincinnati reported on stroke patients ages 18 to 54 from various years in the extended Cincinnati area: 1993 to 1994 1999, and 2005. They found that use of both cocaine and marijuana increased over the time of the study, and that 20 percent of those who had a stroke abused these illegal drugs.
A French study published in 2011 noted the incidence of stroke among 48 young adults. The authors reported that in 21% (10) patients there was stenosis (narrowing) of the brain blood vessels associated with use of marijuana.
A study published in the same year examined stroke among people aged 15 to 50 years in South Australia from January 2006 through June 2010. A total of 326 patients (184 males) were evaluated. Fifty-one of the patients used illicit drugs, mostly marijuana and amphetamines.
The bottom line
One problem with the newest study is that the authors did not know the cigarette smoking status of the controls. All but one of the stroke patients also smoked tobacco regularly. However, Barber stated that he believed the risk of stroke seen in the study was associated with marijuana use and not tobacco.
Use of marijuana remains a controversial topic, despite its acceptance for medical purposes in many states and its newly won limited legal status. Individuals who chose to use marijuana should be aware of the possible risk of stroke and healthcare providers should consider marijuana use as a contributor when accessing younger stroke patients.
Barber PA et al. Cannabis, ischemic stroke and transient ischemic attack: a case control study. International Stroke Conference 2013; abstract 147
De los Rios F et al. Trends in substance abuse preceding stroke among young adults: a population-based study. Stroke 2012 Dec; 43(12): 3179-83
Phillips MC et al. Ischaemic stroke among young people aged 15 to 50 years in Adelaide, South Australia. Medical Journal of Australia 2011 Nov 21; 195(10): 610-14
Wolff V et al. Cannabis use, ischemic stroke, and multifocal intracranial vasoconstriction: a prospective study in 48 consecutive young patients. Stroke 2011 Jun; 42(6): 1778-80