Strokes kill 140,000 Americans each year and nearly 800,000 suffer from an attack. But a promising study suggests that cannabis may lower a person’s risk of having a stroke.
The research, conducted at the Center for BrainHealth at The University of Texas and published in the journal, “Neuropsychopharmacology,” found marijuana improves oxygen and blood flow to the brain, reducing the risk of clots that cause a brain attack.
Dr. Francesca Filbey, the lead researcher and her team have discovered that the “primary psychoactive ingredient present in cannabis —tetrahydrocannabinol (THC) — relaxes arterial walls resulting in lower blood pressure and increased blood flow to tissues.”
The research team also claim that frequent cannabis consumers have the lowest risk for stroke because of their extremely efficient brain blood flow.
While the reason for the brain changes related to chronic marijuana use is unclear, Filbey said that these changes may reflect underlying differences in brain tissue metabolic rate.
“Past marijuana research has shown changes in cognitive functions such as memory and executive functioning. Our study seeks to understand the possible neurophysiological mechanisms that may drive these cognitive changes,” said Filbey, who is also Bert Moore Chair in BrainHealth and head of the cognitive neuroscience program in the School of Behavioral and Brain Sciences.
The study consisted of 74 cannabis users and 101 nonusers matched for age and IQ. All users reported at least 5,000 usages over their lifetime and daily use for 60 days leading up to the study. Participants were required to refrain from cannabis for 72 hours before the study to eliminate acute effects of the drug. Participants underwent magnetic resonance imaging, and THC metabolite levels were measured using urinalysis.
Filbey and her team found that cannabis users showed “higher global oxygen extraction fraction and cerebral metabolic rate of oxygen” compared to nonusers. Also, blood flow in the putamen — an area of the brain associated with reward learning and habit formation — was found to be greater in users than nonusers.
Increased blood flow in the putamen may either reflect the capacity of THC to dilate blood vessels or the development of additional circulatory pathways.
“Currently, cannabis is the most widely used illicit drug. As it becomes more widely legalized, understanding neurophysiological alterations and its effects on the brain’s health and performance are becoming increasingly relevant,” Filbey said.