The Legend: Marijuana seeds contain some substance that, when smoked, will leave a man sterile.
Status: False
Analysis:
Exactly what is it in those seeds that would leave a man sterile? According to Michael Tierra in his book Planetary Herbology, marijuana seeds are 19% protein, 31% lipids, choline, trigunelline, zylose, inositol, phytin and various enzymes. There is virtually no THC in cannabis seeds, which is why they remain legal to buy and sell. Lipids are fats and oils. Choline and inositol are part of the B Vitamin complex, they're nutrients. Zylose is a sugar. Trigunelline and phytin are types of salt. There doesn't seem to be anything there that would inhibit sperm production or health.
There seem to be many pot-smoking cultures with healthy birthrates, including our own here in the U.S. As marijuana use, and presumably the practice of smoking seeds, steadily increased in this country, peaking in 1979, there was a concomitant rise in the rate of teen pregnancy, (U.S. Teen Pregnancy Statistics, 2006). We would not see that trend if marijuana seed smoking was reducing fertility in males.
There is some research that suggests that sperm motility can be temporarily affected by the THC content of smoked marijuana, (Whan et. al., 2006), but other research shows that sperm motility is effected just as much by the tightness of a man's underwear, (Sanger & Friman, 1990).
