Marijuana Use May Lower Sperm Counts 'Quite a Lot'

Smoking marijuana more than once a week may lower men's sperm counts by about a third, according to a new study. Researchers found that the men in the study who smoked marijuana more than once a week had sperm counts that were 29 percent lower, on average, than those who did not smoke marijuana, or used the drug less frequently. The researchers thought that amount of reduction in sperm count "was quite a lot," said study author Tina Kold Jensen, of the University of Copenhagen in