News & Comment » Green Zone

The Straight Dope

Let's put some cannabis-related myths to the test


Separating fact from fiction.
  • Separating fact from fiction.

Maybe it was all those years of cannabis culture existing largely underground that led to the bevy of tall tales and myths associated with the substance. Or maybe people were just super high when they came up with some of these. Then again, there could be some truth to be found.

You've heard some of these, for sure, but let's dig in and find some reality.

HYPOTHESIS: Coughing after inhaling increases the effects of the pot

REALITY: There's nothing fun about a coughing attack, regardless of what brings it on. But that didn't prevent the spread of the dorm-room belief that coughing after smoking cannabis makes you much higher.

There is very little good science to be found on this one, but science does tell us that the coughing reaction is our body's way of trying to clear the lungs. The theory is that your lungs expand while coughing, and that lets more THC — the primary psychoactive compound in cannabis — into your system. That's not likely. What's more likely? A coughing fit makes it difficult to breathe, causing lightheadedness.

George Washington grew cannabis... fields of it

Yes, our first president did grow cannabis on his plantation at Mount Vernon, but according to his presidential library, it was industrial hemp. The hemp he grew likely had less than 0.3 percent THC levels. His cash crop was used for making everyday items like rope, paper and other necessary items.

So that monologue in Dazed and Confused about Martha loading up a big bowl for George when he got home every night is probably not accurate. This is not to say, however, that Martha wasn't a hip, hip lady in other ways.

Marijuana is the nation's biggest cash crop

This assertion has been widely stated, especially by those against cannabis prohibition who argued that the nation was missing out on enormous tax revenues. A 2006 report by the National Organization for the Reform of Marijuana Laws valued America's marijuana crop at $35.8 billion. The 2012 book Marijuana Legalization: What Everyone Needs to Know, however, found that the total was closer to about $4 billion, at most. The book argues that production and sales values of marijuana were often confused and overstated. But as more states legalize the production of marijuana, these statistics will be more closely monitored and evaluated, so someday we may have some definitive truth on this statement. (Corn crops are currently valued at about $50 billion.)

Using cannabis lowers your sperm count

You may remember hearing that smoking pot makes you less of a man by decreasing your, um, little men, if you will. A 2015 study from the University of Copenhagen found that men who used marijuana more than once a week had sperm counts 29 percent lower than the men in the study who didn't smoke.

The reason that this study and similar studies haven't been found to be definitive? The subjects who regularly used cannabis also tended to use other drugs, including alcohol, which could perhaps also lower sperm counts. ♦