A stroke occurs when the brain is deprived of blood and the oxygen it contains, after which brain cells rapidly perish, possibly threatening life or leading to loss of speech and/or paralysis and a requirement for long-term rehabilitation. A new study published in the journal Neuropsychopharmacology indicates that cannabis might lessen the risk of a stroke. 29 US states plus the District of Columbia, which is not a state, oh no, now permit cannabis for medical reasons, while five states allow it recreationally, but the federal government insists in the face of all evidence (here, for starters) that it has no proven medical benefits.
Now we have yet more proof, this time courtesy of a study by Dallas’ University of Texas which has concluded that the drug improves the flow of blood to the brain, lessening the risk of the clots that lead to a brain attack and so reducing the risk of a stroke. It was chronic users who had the most productive brain blood flow.
Dr Francesca Filbey, director of Cognitive Neuroscience Research in Addictive Disorders at the university’s Center for Brain Health, led a team which examined 74 cannabis users and 101 deprived people for 60 days. She commented that tetrahydrocannabinol (THC), the ingredient of cannabis which gets you high, certainly relaxes blood vessels and changes the brain’s blood flow. This study examined how extensive THC intake could affect the risk of a stroke.
This was accomplished by analysing the differences in regional brain blood oxygenation in oh-so-habitual cannabis users: people who took it on each of the 60 days prior to the study. They did, however, have to abstain from usage for the dreadful 72 hours beforehand to preclude the drug having acute effects.
Participants were subjected to magnetic resonance imaging while THC metabolite levels were gauged by urinalysis. The users displayed greater global oxygen extraction and cerebral metabolic rate of oxygen than the non-users. The more dope they took, the greater the effect. It was also found that blood flow in the putamen, the bit of the brain that does habits, learning and reward, was greater for users; this could be because blood vessels are dilated by THC or because it develops new circulatory pathways.
Dr Filbey remarked that with cannabis being the most oft-used illegal drug and its becoming more legal, its effects upon the brain were ever more relevant. Her team did not claim that cannabis usage directly reduced the risk of a stroke, so let’s do it for them.
Pick yer study
Of course, another study, this time presented at the American College of Cardiology’s 66th Annual Scientific Session in 2017, found cannabis to increase and not lower the risk of a stroke, but this was based on hospital discharge records and doesn’t reflect the general population since patients were already sick. We might prefer to listen to the 2016 study of 50,000 young Swedish adults which found “no evident association between cannabis use in young adulthood and stroke.” Or there was the 1975 study which found that daily intake of THC by young male volunteers diminished blood pressure and heart rate. Not to mention the 2011 study showing that ceasing cannabis use led to a rise in blood pressure and heart rate.