Men who were heavy marijuana smokers in their teenage years may not live as long as those who did not use the herb when they were young, a new study has found.
Scientists from the Karolinska Institute in Stockholm examined data from more than 45,000 men in Sweden who underwent mandatory military training between 1969 and 1970 and were followed for the study until 2011.
During the 42-year study period, about 4,000 of the men died. The researchers found that those who were heavy marijuana users in their late teens were 40 percent more likely to die by age 60 than those who had never used the drug.
“Heavy use” was defined as using the herb more than 50 times.
The researchers also found that the risk of death from suicide or an accident was directly proportional to the level of marijuana use the men had indulged in as teens.
The findings were published online in the American Journal of Psychiatry on Friday.
The study nevertheless did not prove definitively that early and heavy marijuana use led to an early death.
While a previous study of the same group of men showed no link between marijuana use and death, this new study covered a longer period (42 years), by which time the men had reached ages when the harmful effects of previous marijuana use, including cancer, lung and heart disease, were more likely to have developed, the researchers indicated.
Addiction expert Scott Krakower told CBS News that marijuana users generally had poorer health, and other studies had found early heavy marijuana use was linked with lung cancer and heart problems.
“Marijuana users generally may have poorer diets and they might be tobacco smokers. There’s an increased linkage between weed and tobacco,” said Krakower.
Dr Kevin Hill, a member of the American Psychiatric Association’s Council on Addiction Psychiatry, told the network: “One of the key messages from a study like this comes down to two words: ‘dose matters.’”
Heavy use of marijuana at a young age was linked to poor psychological health and cognitive problems, which may in turn lead to poor food and health choices, Hill said.
