The Dew rumor's recent growth spurt may be partially due to a surge in the popularity of the drink itself. According to figures compiled by Beverage Digest, as of this writing Mountain Dew is the fastest-growing soft drink in the U.S.
As I mentioned earlier, the spread of these tall tales among young people has some health care officials worried. The state of Wisconsin warned parents, for example, that the notion that Mountain Dew functions as a spermicide could spark a rise in the number of unwanted pregnancies if it goes unchallenged. Marjorie Saltzman, a longtime Planned Parenthood volunteer in Portland, Oregon, has lobbied PepsiCo to address the misinformation through advertising or special warning labels so far without success, she says (the company claims it has never received a consumer inquiry or complaint in connection with the rumor).
To its credit, PepsiCo has responded forthrightly to questions from the press, but its PR folks would do well to resist the temptation to adopt a dismissive attitude toward this urban legend. Granted, it's a "schoolyard tale" with no foundation in fact, comparable to Elvis sightings and the like, but bumping into a dead rock star at the 7-11 has never, to my knowledge, resulted in an unwanted pregnancy.
Just because a rumor is silly doesn't mean it's harmless.