My 15 year old rocker use to love to drink Mountain Dew, even though it made him bounce off the walls and never stop talking. Recently he has refused the beverage claiming that the yellow #5 dye in this soda will make his “balls shrink.” Is there any truth to this statement? Kids have drunk Mountain Dew for years–this is the first time I have ever heard this one! –Concerned mother

First thing you gotta do, ma, is give that kid a smack upside the head. Mountain Dew will make his “balls shrink”? The proper expression when one speaks to adults is “testicular atrophy.” See how far he gets asking the Pepsi company about shrinking balls.

Not that he’ll get real far no matter how he phrases this oft-heard story. A spokesperson for Pepsi, which makes Dew, denies that the product has–another euphemism coming up here–adverse effects on the human reproductive system. Likewise from Coca-Cola, maker of Mello Yello, which also contains FD&C yellow number five (hereinafter to be called by its common name, tartrazine). The Food and Drug Administration says pretty much the same thing.

But see, the problem is we’re asking the wrong question. We should inquire whether tartrazine has any adverse health effects, period. Unsurprising answer: you bet. I reviewed the medical literature and found nothing about tartrazine making your balls or any other portion of your anatomy shrink. But there does seem to be consensus that in some individuals it can cause hives, swelling, or asthma. A few researchers also think it can cause hyperactivity in kids. So if Mountain Dew made your 15-year-old rocker bounce off the walls, the cause might not have been strictly the caffeine.

Tartrazine is found in numerous food products, including canned vegetables, chewing gum, hot dogs, pasta, ice cream, and fruit juice concentrate. The stuff accounts for 85 percent of the food dye you consume each day. It’s used to improve (well, alter) the aesthetics of many foods sold to children–macaroni and cheese comes to mind–so kids typically get a lot more than adults.

How common is tartrazine sensitivity? The numbers in the literature are all over the place, but there does seem to be a close link between tartrazine and aspirin, which triggers asthma attacks in 10 to 16 percent of adults and 2 to 6 percent of children. As I read it, if you’re not sensitive to aspirin, you probably won’t be sensitive to tartrazine either. But if you are aspirin-sensitive and you get asthma attacks that aren’t provoked by aspirin or any other obvious cause, you might check the ingredients of stuff you’ve eaten lately and see if they include yellow number five.

How does white chocolate differ from regular chocolate, other than the color?

–Jared Anderson, Blacksburg, Virginia

Well, one distinction of some possible significance is that, legally, white chocolate doesn’t exist. True chocolate contains pulverized roasted cocoa bean, consisting of cocoa butter and cocoa solids. White chocolate contains no cocoa solids and thus technically is “white confectionery coating.” Beware–some white confectionery coatings don’t even contain cocoa butter and thus can be considered chocolate only by application of the homeopathic principle. Even in “real” white chocolate the chocolate flavor is subtle at best, being to real chocolate what American beer is to beer. But whatever floats your boat.

I’ve often wondered: what’s the difference between a philharmonic orchestra and a symphony orchestra?

–Formerkid, via AOL

My hypothesis going in was that a philharmonic orchestra had a guy named Phil playing the…ah, you don’t want to know. Suffice it to say there is no difference.

In your book The Straight Dope you state that Coca-Cola will dissolve aluminum. My question is this: How is it that this beverage is sold in aluminum cans without oxidizing them?


According to Coke, the cans are “coated with a very thin layer of a type of light, food-grade plastic material approved by the FDA.” Its effect on the size of your testicles I decline to say.

Art accompanying story in printed newspaper (not available in this archive): illustration by Slug Signorino.