The findings suggest they have narrowed arteries, similar to patients with high blood pressure and dementia, and could help explain reports that heavy marijuana users have trouble on memory tests, said the researchers at the National Institute on Drug Abuse in Baltimore.
Ronald Herning and Jean Lud Cadet tested 54 marijuana users, who smoked anywhere between two and 350 joints a week, and 18 non-smokers.
They found that blood flow improved in people who smoked up to 70 marijuana cigarettes a week -- people they defined as moderate users -- after a month of avoiding cannabis.
Heavy users, who smoked up to 350 joints a week, saw no change in blood flow even after a month, the researchers said.
The NIDA is telling us 70 joints a week is moderate use and 350 joints a week is heavy use. How could anyone smoke that much pot? Why would anyone want to smoke that much pot? Is it even physically possible? These researchers might need to scan their own brains.