Science/Medicine : The enduring myth of Aphrodisiacs
Recent news stories have reported that marijuana sparks the sex drive by raising testosterone levels, tranquilizers prolong male “staying power,” substances isolated from human sweat enhance sexual desire, room deodorants intensify orgasms, neurotransmitter boosters extend arousal for hours and antidepressants “drive” women to new sexual highs.
In a society that asks medical science to cure everything from plagues to pimples and wrinkles, the search for better sex through chemistry is hardly surprising.
But are the stories true? Do genuine aphrodisiacs exist? The good news is that the answer is a qualified “maybe.”
“If you mean a substance that makes the object of your affection fall in a swoon into your arms, the answer is no,” said Dr. John Money, a medical psychologist at Johns Hopkins University School of Medicine who pioneered research in sexuality and drug use. But “if you mean some things in small amounts that enhance the intensity of sexual pleasure sometimes in some circumstances for some individuals--perhaps.”
The bad news is that for healthy men and women, shopping in Aphrodite’s drugstore for new sexual thrills carries serious risks--emotionally and physically.
To begin with, evidence of aphrodisiac effects lacks scientific credibility. It is largely, if not wholly, anecdotal, inferential, spotty and unconfirmed.
A few years ago, for example, experiments by Gian Luigi Jessa, a pharmacologist in Sardinia, created something of a sensation with reports that a diet free of tryptophan, a nutrient found in milk, cheese and other dairy products, caused lab animals to become oversexed, apparently by depleting them of serotonin, a brain chemical important in mental activity.
But no similar results have been reported in human or additional animal studies. And it’s not even clear that such experiments have been done.
There was another surge of interest caused by a report this year in the Canadian Journal of Psychiatry that three patients taking clomipramine, an antidepressant, experienced “irresistible sexual urges” and instant orgasms. And the American Journal of Psychiatry reported increased sexual desire in six of 13 patients on trazodone, another antidepressant. Less well publicized are the more numerous reports of suppressed sexual responses from these drugs.
Although research in aphrodisiacs is staffed by some notable psychiatrists, psychologists, pharmacologists, endocrinologists, chemists and neurologists, the fact is that precious few controlled clinical trials have ever been done, even with drugs that offer good leads. And they may never be done.
The scientific establishment generally condemns or ignores research on healthy people that suggests positive effects of a chemical on sexual performance. The reasons are partly ethical--giving drugs to healthy people carries risks--and partly cultural--there is great unease with the idea of encouraging sexual prowess.
“As a result,” Money said, “practically nothing is known about dosages, tolerance or the influence of age or gender or personality on the effects of any aphrodisiac.” And given the Puritan attitude toward sex in much of society, he added, “there is serious question about whether we’ll ever be allowed to find out.”
What credible scientific evidence there is on the influence of drugs and hormones on sexual behavior has been drawn from reported side effects of necessary drug therapy or from studies among people who are unhappy or sick, physically or emotionally--including drug addicts, prostitutes, transsexuals, the sexually disordered and people born with abnormal sex hormone and gender characteristics.
Examples:
European scientists have discovered that a few women taking bromocriptine mesylate, a fertility drug that acts on a gland at the base of the brain, report higher-than-ever interest in sex. The drug also reportedly increased sexual interest in a few men with abnormal levels of prolactin, a fertility hormone. But the drug has dangerous side effects and is at best prescribed only for women with pituitary tumors that cause infertility.
L-Dopa, a chemical building block of dopamine used to treat Parkinson’s disease, was incidentally found to restore sexual interest in about 1% of the victims of this palsy. A few scientists then tried it on non-Parkinson’s individuals as an aphrodisiac. But inconsistent results and side effects stopped the studies. One finding was that the drug seemed to have aphrodisiac effects only on those who needed it least.
Drugs commonly used to treat high blood pressure and depression have been reported in a few instances to arouse or sustain sexual pleasure.
PCPA, a drug that inhibits serotonin and is used to treat migraines, has increased sexual arousal in a few patients.
Naloxone, used to treat narcotic addiction by blocking the brain cell receptors that activate opiates, also stops the poisonous effects of narcotics, including suppression of sex drive. That knowledge led to tests of naloxone on eight healthy men. Three had a spontaneous erection. Similar studies in four women found that three claimed enhanced sexual pleasure.
Drs. John Buffum and David Smith reported in 1981 that an infertility drug called clominphene citrate improved sexual function in one man given the drug to treat liver disease and impotence, probably by correcting a sex hormone imbalance. And they also report that zinc given during blood dialysis to several men with a form of blood poisoning corrected the sexual impotence that resulted from their disease.
In 1984, French scientists reported that papaverine hydrochloride, a drug used to treat coronary spasms and stroke, could induce an erection, probably by sabotaging biochemical receptors in both brain and muscle cells.
What such experiences have to offer healthy individuals is at best unclear and at least cause for concern.
For the healthy, the notion of undergoing hemodialysis (oral zinc does not work), playing with hormone balances, risking organ damage from anti-hypertensive medication, taking powerful drugs that block brain cell activity or exploring the sexual unknown at the risk of equally unknown side effects hardly seems rational.
In general, legal drugs with aphrodisiacal side effects do not work on people with normal biochemistry, as was the case with L-Dopa.
Users of illegal or dangerous substances also have reported some aphrodisiac effects, but they are often considered less than credible. “Many,” Money quipped, “risk arrest if they were honest about their drug experiences or their sexual experiences.”
Some reputed aphrodisiacs can also cause serious damage. These include alcohol, barbiturates, marijuana, cocaine, “poppers” (amyl nitrite), LSD and other hallucinogens, amphetamines, MDMA (so-called Ecstasy), MDA and Quaaludes (methaqualone).
Experts on these chemicals point out that their physical and psychological effects can indeed produce intense feelings, sensations and sensitivity to the environment. They seem to lower inhibitions, relax muscles, enhance the senses, produce a sense of well-being and power, and distort unpleasant reality.
All these drugs have some dangerous side effects. Less well appreciated is the fact that they also produce counter-erotic effects with regular use or even moderate overdose.
In Shakespeare’s words, alcohol “provokes the desire, but it takes away the performance.” It is not a stimulant, but a central nervous system depressant.
Chronic high doses of amphetamines, including “speed,” break down blood vessels and brain cells that affect dopamine uptake, resulting in a burnout of the very sexual system first turned on and turned up by the stimulants.
Long-term use of cocaine and narcotics completely suppresses sexual interest, experts say.
Barbiturates, powerful sedatives, produce drowsy euphoria, excitement and emotional swings, but they eventually bring physical addiction, psychotic behavior and--when withdrawn--nausea, cramps, delirium, convulsions and the very conditions the drugs were meant to stop, such as anxiety, panic and loss of interest in sex.
What is the outlook for true aphrodisiacs in the future, a safe, effective means of initiating or enhancing erotic pleasure?
Brain and biochemistry are the targets of intense scientific investigation that is certain to unravel the precise pathways by which humans become sexually aroused. That would open the door to the synthesis of chemicals that play the same roles as nature’s means.
At the Monell Chemical Senses Center at the University of Pennsylvania, investigators have already filed patent applications to make four pheromones, hormone-like sexual aromas made by animals and, it appears, by humans.
Winifred Cutler, a biologist who helped conduct some of the studies, foresees a mass-produced male essence in creams or sprays that could change a woman’s sexual mood. But because there are more than 200 chemicals involved in male and female odors, a commercial “eau de male” is years off.
Scientists studying the sense of smell are also experimenting with odorants that evoke pleasant memories and could be tailored to help individuals associate past desire for sex with a particular scent.
A sex researcher at Brown University has shown that fear and anxiety triggered by stress and even horror movies prime many people for increased sexual response, possibly by sparking the release of brain chemicals involved incidentally in sexual arousal.
For the most part, the prospects for chemical aphrodisiacs are weak, far away or unrealistic.
Even with drugs that have sex-enhancing properties, sex therapist and psychiatrist Helen Singer Kaplan noted, the chemical activity may differ from person to person and, at times, even in the same person as a result of psychological and physical factors.
For example, studies of users of LSD, often touted as a powerful erotic stimulant by “acidheads,” have found that the drug actually reduced sexual interest and performance.
Some experts label the search for chemical love as misguided socially, culturally, psychologically and biologically. Psychologist Robert Dain of the University of Texas Health Science Center in Dallas, for example, wonders why today’s liberated women do not find the whole notion as outmoded as keeping women out of the workplace.
“Did you ever notice,” he asked, “that typically it’s the male who wants the aphrodisiac--not for himself but his partner?” In one sense, he suggested, aphrodisiacs are little more than a kind of chemical rape, a means of manipulating women.
At the very least, drugs in the service of sex do seem to subvert or at least trivialize important aspects of sexual experiences, such as love, romance, commitment, trust and health. Nor do they encourage people to explore the richness of real life and the power of imagination and fantasies.
What still seems most true about aphrodisiacs is the observation made by the late Alfred Kinsey, the father of modern sex research, that the best, if not the only aphrodisiac, is the human mind.
WHAT MIGHT ENHANCE SEXUAL RESPONSE
The scientific establishment generally condemns or ignores research on healthy people that suggests positive effects of a chemical on sexual performance. What credible scientific evidence there is has been
drawn from reported side effects of necessary drug therapy or from studies among people who are under treatment for physical or emotional illness unrelated to sexual behavior.
REFRAINING FROM MILK AND DAIRY PRODUCTS
A few years ago, experiments by Gian Luigi Jessa, a pharmacologist in Sardinia, created a sensation with reports that a diet free of tryptophan, a nutrient found in milk, cheese and other dairy products, caused lab animals to become oversexed, apparently by depleting them of serotonin. But no similar results have been reported in human or additional animal studies. And it’s not even clear that such experiments have been done.
DRUGS AND HORMONES
In general, legal drugs do not show aphrodisiacal effects on people with normal biochemistry. Users of illegal or dangerous substances have reported some aphrodisiac effects, but they are often considered less than credible. For the healthy, using drugs meant for medicinal purposes may mean playing with hormone balances or risking organ damage.
ALCOHOL AND NARCOTICS
Alcohol, a central nervous system depressant, “provokes the desire, but it takes away the performance,” it has been written. Chronic high doses of amphetamines, break down blood vessels and brain cells that affect dopamine uptake, resulting in burnout of sexual response. Long-term use of cocaine and narcotics completely suppresses sexual interest, experts say.
AND WHAT WON’T . . .
Among the reputed aphrodisiacs that belong in the category of science fiction or wishful thinking, because there is ample scientific evidence that they do not work, are:
Spanish fly, or cantharides, made from the outer coat of a small beetle. Spanish fly irritates sensitive membranes and causes itching. The theory was that such an itch inside the vagina would feel better during intercourse. Not true. The facts are that Spanish fly produces a painful erection in some men and has killed some users by triggering convulsions and kidney failure.
Room deodorizers and liquid incense. When inhaled, the substances can dilate blood vessels in the genitals, causing congestion of blood there. But there is no scientifically known connection between congestion and prolonged or intensified orgasm. Here, as with many alleged aphrodisiacs, the effect may be one of expectation.
Ginseng. Its only value biologically is as a source of some vitamins. Its value as an aphrodisiac probably arose because the root from which it comes looks somewhat humanoid.
Nutmeg. Oddly enough, this spice is related to a group of chemicals similar to amphetamines, but about the only known effect when given in high enough doses to get one is hallucinations. At those doses, the drug causes all loss of interest in sex. Users get sick.
Chocolate. Is the candy you take to your sweetheart an aphrodisiac? Cocoa contains phenylethylalanine, a chemical that influences regulators of the brain’s pleasure centers.
