The other day, when I told my boyfriend, Sean, that I was going to be doing a little research on aphrodisiacs, he was surprisingly keen to help out. "I'll buy the bacon," he said.

"Bacon is not an aphrodisiac," I said.

"Wanna bet?" he challenged.

Sean loves bacon—and, come to think of it, it did seem to put him in the mood for love. (On reflection, I realized that I had unconsciously begun incorporating it into more and more meals, wrapping thin strips around chunks of cod and adding crispy bits to pasta sauces).

But can food produce sexual desire? Or, to put it another way, do aphrodisiacs actually exist? Many people think so. An online poll conducted by sex therapist Linda De Villers found that strawberries, ice cream, pasta, and whipped cream are the four foods most commonly associated with lust. But according to Martha Hopkins, coauthor of The New InterCourses: An Aphrodisiac Cookbook, there are no real aphrodisiacs. "Still," she laughs, "whatever makes you groan when you eat it counts."

If you think about it, a greasy slab of cured pork belly is no odder than many other foods that have historically been considered aphrodisiacs: asparagus, artichokes, avocadoes, bananas, black beans, chili peppers, figs, licorice, and pine nuts have all been hailed for their ability to arouse desire. The Aztecs called the avocado tree a "testicle tree" because its fruit hangs in pairs. In renaissance Europe, women were forbidden to eat artichokes, which according to legend had been created when the Greek god Zeus transformed a young maiden into the spiky vegetable. As a result, they were prescribed to men to improve their bedroom performance. Of history's most famous aphrodisiacs, only chocolate and oysters still hold claim to their sensual reputation.

Over time, different foods acquired reputations as sexual stimulants for two reasons. In some cases, it physically resembled a sex organ (avocados and carrots look like male genitalia; oysters and figs are reminiscent of female private parts). In others, the food mimicked the fire of passion; chili peppers, for example, may cause sweating and increased heart rate and circulation, just as sexual intercourse does. Spanish fly, one of the world's most celebrated aphrodisiacs, can cause genital burning, which is sometimes considered synonymous with sexual excitement. (Unfortunately, that burning is caused by an acidlike juice, cantharidin, which is highly toxic.)

While the physical suggestion of sex may be enough for some, modern research shows that some classic aphrodisiacs can stimulate desire— and increase performance. Oysters, for example, contain high levels of zinc, which has been associated with increased sexual potency in men; the eighteenth-century womanizer Casanova was said to have eaten 50 oysters for breakfast with his mistress in a bathtub built for two. And the fibrous tissue of Asia's prized aphrodisiac, the rhino horn, contains both calcium and phosphorous— minerals that, when deficient (as they often were in ancient times), can lead to muscle weakness, fatigue—and therefore a preference for quickies rather than slow, sensual sex. (It also conveniently resembles an erect penis.)