New research suggests marijuana users have significantly lower levels of blood flow in the brain compared to nonusers.
The findings point to a higher risk of memory loss and the development of brain conditions like Alzheimer’s, Daily Mail reported.
The researchers at Amen Clinics looked at brain scans from patients from California, Georgia, New York, Virginia and Washington from over a 20-year period. All of the 1,000 marijuana users had lower blood flow levels than the control group of nonusers, noted the study, which was published in the Journal of Alzheimer's Disease.
“As a physician who routinely sees marijuana users, what struck me was not only the global reduction in blood flow in the marijuana users brains, but that the hippocampus was the most affected region due to its role in memory and Alzheimer's disease,” said co-author Dr. Elisabeth Jorandby.
Previous studies found that marijuana could protect brain cells by helping them grow and shielding the brain from stress, Medical Daily reported.
“Our research has proven that marijuana users have lower cerebral blood flow than nonusers,” Jorandby added.
The study found the right hippocampus is the most affected among marijuana smokers. The right hippocampus is a crucial part of the brain in the development of Alzheimer's.
“This work suggests that marijuana use has damaging influences in the brain -- particularly regions important in memory and learning and known to be affected by Alzheimer’s,” said Jorandby.
The study noted that moves to legalize medical marijuana may be moving faster than research supports.
“The media has given the general impression that marijuana is a safe recreational drug, this research directly challenges that notion,” added Dr. Daniel Amen, who founded Amen Clinics.
A separate study published earlier in November found more evidence about the impact of long-term marijuana use on dopamine levels.
“The dopamine system is central to learning and motivation. We conclude that long-term cannabis use in people is linked to blunting of the dopamine system,” said Professor Oliver Howes of Imperial College London, according to Sci-News.
Many questions about the effects of marijuana on the brain remain to be explored.
“We urgently need to better understand how cannabis affects the brain, to help policy makers and individuals make informed decisions,” Howes added.