BERKELEY, CA - MARCH 25: Medicinal marijuana user Dave Karp smokes marijuana at the Berkeley Patients Group March 25, 2010 in Berkeley, California. California Secretary of State Debra Bowen certified a ballot initiative late yesterday to legalize the possession and sale of marijuana in the State of California after proponents of the measure submitted over 690,000 signatures. The measure will appear on the November 2 general election ballot. (Photo by Justin Sullivan/Getty Images)
A new study out of New Zealand is a real harsher: cannabis users double their risk of stroke, according to Dr. P. Alan Barber of Auckland.
People aged 18 to 55 who had a stroke "were 2.3 times as likely to test positive for marijuana in their urine than those who didn't have a stroke," according to Everyday Health.
The study does not prove that smoking pot "will cause a stroke," the news source reported. But Barber points out that "a lifestyle that includes cannabis use is closely associated" with a stroke.
Unknown in the study is whether tobacco played a role in stroke risk. In fact, the study did not look at tobacco use -- a very unhealthy habit -- at all. This is a "major problem with the study," according to the news source.
A total of 16 percent of stroke patients tested by Barber for drug use tested positive for cannabis; 8 percent of patients tested who had not had a stroke were cannabis-positive, according to the study.