In a finding that should give new ammunition to those fighting for the legalization of marijuana, a study has determined pot is far safer than alcohol, and is in fact 114 times less deadly.
That fact that you are far less likely to die from overdosing on marijuana than from alcohol is seen as likely to be cited by those who say marijuana should be legalized and controlled just as alcohol is.
In the study, led by British researcher David Nutt, the risk levels associated with substances including marijuana, alcohol, nicotine and illegal drugs such as heroin, cocaine, methamphetamines and ecstasy were compared using an approach known as the margin of exposure, which compares lethal doses of a substance with the amount normally consumed by recreational users of the substance.
The mortality risk represented by cannabis was approximately 114 times less than that of alcohol, the study found, and in fact pot was the single substance rated as "low risk" by the researchers.
Alcohol, along with heroin, cocaine and nicotine, was classified as "high risk," they reported in the journal Scientific Reports.
The new study is in line with previous research that suggested it would take more marijuana than a person could possibly smoke at one sitting for it to be lethal.
The U.S. Drug Enforcement Administration has estimated someone would have to consume "20,000 to 40,000 times as much marijuana as is contained in one marijuana cigarette" to ingest a lethal dose.
In contrast, 15 shots of alcohol over a 3 to 4-hour period could raise a person's blood-alcohol level to .34 percent, a potentially fatal level.
"Specifically, the [study] results confirm that the risk of cannabis may have been overestimated in the past," the researcher wrote. "In contrast, the risk of alcohol may have been commonly underestimated."
The study authors suggest alcohol and tobacco should be prioritized above marijuana in terms of risk management, and that governments, instead of maintaining current prohibitions against marijuana, should legalize and regulate its sale and use.
Those prohibitions have been based largely on anecdotal evidence rather than quantitative or qualitative analyses, the researchers say, meaning current classifications of marijuana are based more on "educated guesses" than on scientific data.
"The results [of the study] make perfect sense," says Nutt, chair of the neuropsychopharmacology department at Imperial College London. "The ultra-low mortality of cannabis has long been recognized with health harms greatly exaggerated."
He says he recommends marijuana be legalized at least for medical use, "as the clear harms are well outweighed by the health benefits."
