Marijuana Kills! But Not Very Often. Especially When Compared to Alcohol and Tobacco.


Heritage Foundation

In a new Heritage Foundation video, anti-pot activist Kevin Sabet bravely tackles "the myth that marijuana doesn't kill." Although cannabis consumers (unlike drinkers) do not die from acute overdoses, he says, "marijuana does kill people" through suicide, chronic obstructive pulmonary disease, car crashes, and other accidents. 

I won't say Sabet is attacking a straw man, since overenthusiastic cannabis fans have been known to say that "marijuana doesn't kill anyone" (although the top Google result for that phrase is an article by Sabet explaining why that's not true). But I will say that Sabet manages to obscure the fact that marijuana does not kill people very often, especially compared to the death tolls from legal drugs such as tobacco and alcohol, which is the relevant point in evaluating the scientific basis for pot prohibition. Let's take a closer look at the four ways that marijuana kills, according to Sabet: 

Suicide. Some research does find a correlation between suicide and marijuana use, but that does not mean the relationship is causal. A longitudinal study published by The British Journal of Psychiatry in 2009 reached this conclusion:

Although there was a strong association between cannabis use and suicide, this was explained by markers of psychological and behavioural problems. These results suggest that cannabis use is unlikely to have a strong effect on risk of completed suicide, either directly or as a consequence of mental health problems secondary to its use.

Furthermore, there is some evidence that letting patients use marijuana for symptom relief reduces the risk of suicide. Still, if reefer has ever driven anyone to kill himself, that would be enough to prove Sabet's point. You can't say it has never happened!

Chronic obstructive pulmonary disease. "You can't say that smoking a crude plant, a leaf, is good for your lungs," Sabet says, "and so we know that COPD and marijuana are inextricably linked." 

Here is how the American Thoracic Society summarizes the evidence regarding marijuana and COPD: 

Heavy marijuana smokers also are likely to develop lung damage because marijuana smoke contains many of the same harmful chemicals as tobacco smoke. We do not know if smoking a small amount of marijuana (for example, light users who smoke an amount equal to 1-2 joints a month) over a long period of time increases your risk for developing COPD. We do know that in some people (especially those with lung problems), smoking marijuana can make their breathing worse. 

A 2012 study of 5,000 young adults who were followed for two decades, reported in The Journal of the American Medical Association, found that "occasional and low cumulative marijuana use was not associated with adverse effects on pulmonary function." Donald Tashkin, a UCLA researcher who has studied the health effects of marijuana use for many years, told Web MD "the main thrust of the paper has confirmed previous results indicating that marijuana in the amounts in which it is customarily smoked does not impair lung function." 

Assuming that heavy pot smoking causes lung damage, people can avoid that risk by using vaporizers or consuming cannabis in the form of edibles. In that sense it is clearly not true that "COPD and marijuana are inextricably linked." 

COPD kills more than 120,000 Americans a year. According to the CDC, it is "almost always caused by [cigarette] smoking." Neither the CDC, the American Lung Association, nor the National Heart, Lung, and Blood Institute mentions marijuana consumption as a risk factor. Yet Sabet is sure at least a few of those COPD deaths can be blamed on pot, although he does not hazard an estimate. By contrast, he notes that the CDC attributes 480,000 deaths a year to cigarette smoking, which causes not just COPD but a laundry list of ailments, including lung cancer and heart disease. 

"Saying marijuana has never contributed to death or never killed anyone is like saying tobacco hasn't killed anyone," Sabet says at the beginning of the Heritage Foundation video. What he means, he says, is that tobacco smokers, like marijuana smokers, do not die from acute overdoses. But given the enormous gap between tobacco-related fatalities and marijuana-related fatalities, the comparison is reckless. 

Car crashes. "Marijuana is the second most implicated drug in drunk or drugged driving accidents," Sabet says. That is misleading, because "implicated" means a driver killed in a crash tested positive for traces of marijuana, which does not necessarily mean he was under the influence at the time of the crash, let alone that marijuana contributed to the accident. Marijuana can be detected in blood and urine long after its effects have worn off. 

Marijuana does impair driving ability, but not as dramatically as alcohol does, which is why legalization might actually reduce traffic fatalities, assuming that more pot smoking is accompanied by less drinking. "Researchers have now said that [marijuana] doubles the risk of a car crash," Sabet says. By comparison, research indicates that a blood alcohol concentration of 0.10 percent quintuples the risk of a car crash. 

According to the National High Traffic Safety Administration (NHTSA), drunk driving kills about 10,000 people a year. How many people does stoned driving kill? "That's difficult to say," said a NHTSA official who testified at a House hearing on the subject this year. "We don't have a precise estimate." The most he was willing to affirm was that the number is "probably not" zero. 

Other accidents. Sabet says "there are a number of, you have to imagine, injuries in other accidents that result from marijuana that just aren't tallied." Well, yes, since they aren't tallied, you do have to imagine them. But if stoned falls from ladders and so forth were a major cause of death in America, someone probably would be counting them. The CDC, for example, counts about 7,500 deaths from alcohol-related falls each year. It attributes another 8,000 or so deaths to alcohol-related suicide, about 1,600 to acute alcohol poisoning, and some 38,000 to chronic diseases caused by excessive alcohol consumption. All told, it puts alcohol-related deaths (including car crashes) at 88,000 annually. 

What is the comparable figure for marijuana? Tellingly, Sabet does not have one, but he wants you to know it is more than zero. To recap, these are the annual death tolls from three of our most popular drugs, the first two of which happen to be legal: 

Tobacco: 480,000

Alcohol: 88,000

Marijuana: > 0 

"You can't say marijuana doesn't kill anybody," Sabet declares. No, but you can say that marijuana's relative hazards have nothing to do with its legal status.