By Sally Squires
Tuesday, February 13, 2007
The strong desire for food and drink is undisputed. Just ask anyone who has experienced a heartfelt craving for a juicy burger, pizza or ice cream.
But what about the other side of the coin: Can certain foods and beverages increase your physical desire for other people?
That's the idea, of course, behind aphrodisiacs -- an eclectic group of foods and drink, from absinthe and chocolate to lentils, oysters, truffles and even the spice turmeric, that have been touted for thousands of years as ways to increase libido.
The name comes from the Greek words for lust (aphrodisia) and sexual desire (aphrodisiakos), which are themselves related to the name of Aphrodite, the Greek goddess of love and beauty.
The classical poets Ovid and Virgil wrote of aphrodisiacs. Look at the Bible and you'll find aphrodisiacs mentioned in the Song of Solomon as well as in ancient Arab, Chinese and Indian writings. Shakespeare described them. So did the Marquis de Sade. And in more recent culture, movies from "Tom Jones" -- based on Henry Fielding's 1917 novel -- to "Practical Magic" with Sandra Bullock and Nicole Kidman as witches, have featured aphrodisiacs.
But it turns out that there isn't much science behind this outpouring of art.
"The idea behind an aphrodisiac is that there is a compound that would make people feel instantly amorous or attracted to another person," notes Marcia Pelchat, a researcher at the Monell Chemical Senses Center in Philadelphia.
Scientists think that if such compounds exist they are likely to be pheromones -- substances that are smelled rather than eaten. Pheromones are inhaled through the nose, where they can rapidly affect the nervous system through the olfactory nerves. By contrast, compounds that are eaten or drunk must survive hostile stomach acids, be transported through the gastrointestinal tract and then move through the blood to the brain. Not only is this process more time-consuming, but it offers the body the chance to dilute or block the substance from ever reaching its target.
What intrigues researchers is that none of the purported aphrodisiacs works on a statistically significant percentage of those who take them -- a standard way to show the merit of a drug. There are also wide cultural differences in alleged aphrodisiacs, suggesting that the context in which they are taken is key. So while chocolate may be considered an emblem of love in Western cultures, stuffed snails are more likely to light personal fires in China, as Pelchat and her research assistant learned from a visiting Chinese scientist. "It didn't strike us as much of an aphrodisiac," she says with a laugh.
Part of what seems to play a role in the many purported aphrodisiacs is the well-known placebo effect. That is, if you believe it will work, it may. "It goes back to the idea of the mind being the sexiest organ," says Martha K. McClintock, head of the Institute for Mind and Biology at the University of Chicago.
To date, only one food has shown evidence of increasing sexual desire -- and it's not likely to be on the menu of a romantic dinner.
That ingredient? Mother's milk. (No, I am not making this up.)
McClintock and her colleagues tested the effects of having healthy women, aged 18 to 35, smell pads laced with mother's milk and underarm secretions from women who were exclusively breast-feeding their newborns.
The researchers included only participants who had normal menstrual cycles, did not use birth control pills or an IUD and were within 30 percent of their ideal body weight. None of the women had ever given birth. None of them smoked, had sinus problems or other conditions that might interfere with a sense of smell. And none knew the goal of the study or what they were sniffing and applying. All the women chosen to participate had the same reported level of sexual desire when the study began.
Over three months, the team had half the 47 participants rub the pads on the skin under their noses daily. They were also asked to reapply the pads after a shower, after exercise and after meals -- activities that might remove the pad's contents. The women answered a variety of daily questions, including ones that rated their levels of sexual desire and fantasies. The other half used pads containing nothing and answered the same questions.
Reporting in 2004 in the journal Hormones and Behavior, McClintock and her colleagues noted that the breast-feeding compounds "increased sexual motivation of women" by up to 24 percent.
Sexual fantasies also increased. Women exposed to breast-feeding compounds experienced a 17 percent increase in sexual fantasies compared with a 27 percent decrease in the control group. The researchers also found that participants with a regular sexual partner "experienced enhanced sexual desire, whereas those without one had more sexual fantasies," noted the team.
This is the first evidence "of a natural compound that increases human sexual motivation," McClintock says. Similar results have been found in rats.
Does that make something in mother's milk an aphrodisiac?
"If you define an aphrodisiac as something that increases sexual motivation, then this compound is an aphrodisiac," McClintock says. "If you mean that it has to increase sexual arousal, then we don't yet have data that it is an aphrodisiac."
And it also confirms what common sense probably already told you: that the only reason to splurge on oysters, truffles or chocolates is because you (or your loved one) like the way they taste.