aphrodisiacs

aphrodisiacs the name applied to substances producing sexual desire. It is doubtful whether any such substances exist; rather, substances are known which promote sexual activity if the desire is present. The search for and promotion of substances with presumed aphrodisiac activity is of ancient origin. The Roman empress Livia (58 bc–29 ad) used Spanish Fly to doctor the food of other members of the Imperial family, in the hope of promoting sexual indiscretions which could then be used for political advantage. In 1772, the Marquis de Sade laced sweets with Spanish Fly to give to young women. Toxic effects followed and the Marquis was eventually brought to trial for poisoning. Spanish Fly refers to beautiful, iridescent green insects, Cantharis vesicatoria, which contain cantharidin, which is both a vesicant (causes blisters) and a diuretic. The dried beetles were simply ground to a powder and used to adulterate food or drink to be consumed by the victim. Cantharidin was quite useful for the removal of warts, but its use as an aphrodisiac probably relates to the irritation caused to the genito-urinary tract, especially the urethra, so that victims become more aware of their sexual organs. Rhinoceros horn has been considered through the ages to have magical properties, either fashioned into objects or powdered and consumed. Cups made of rhino horn were expected to protect the drinker against poison, and powdered horn was reputed to be useful for many disease states, including impotence, and for promotion of sexual activity. Any effects of rhino horn are almost certainly placebo effects, of which scarcity, improbability, and high cost play a part. Trade in rhino horn is now banned world wide. The mandrake root is also reputed to have aphrodisiac properties.

A number of foods are reputed to have aphrodisiac properties, including asparagus, caviar, eel, garlic, ginseng, honey, lobster, oysters, peaches, and truffles. Many of these foods are exotic, and any effect they have on sexual desire is more likely due to the setting in which they are presented.

In much of the above account the receivers of the supposed aphrodisiac were unaware what was being offered to them. In recent times therapeutic strategies have been developed to assist those who have sexual desire but lack the ability to perform. Male impotence affects large numbers of men from age 40 onwards, because of the inability to maintain an erection. In some instances, for example paraplegics, the nerve pathways from the brain to the penis are interrupted, so that desire cannot lead to an erection. A breakthrough in understanding occurred when it was realized that, to obtain an erection, the penile muscles, especially of the blood vessels, need to relax. This allows the blood spaces to fill causing swelling, the resulting tumescence compressing the veins, preventing venous drainage. Papaverine and phenoxybenzamine, an α-adrenoceptor blocking drug, were amongst the first to be used. The former is a spasmolytic, (a smooth muscle relaxant), whereas phenoxybenzamine prevents vasoconstriction by blocking the effects of sympathetic vasoconstriction and so allowing the filling of the blood spaces. For the latter an intact sympathetic outflow is needed. These agents have widespread activity throughout the body and therefore have to be injected, locally, into the penis. An alternative approach is to increase levels of cyclic AMP locally in the penis, again causing muscle relaxation. This has been achieved by using an inhibitor of phosphodiesterase (which breaks down cyclic AMP). The penile tissue is particularly rich in a particular phosphodiesterase, PDE5, so a specific inhibitor of PDE5 was developed which can be taken orally, namely sildenafil citrate (Viagra). An erection is obtained only when sexual stimulation is present; the drug is therefore useful in male erectile dysfunction, but only if other pathways are intact. Whether phenoxybenzamine or sildenafil should be described as aphrodisiacs is arguable.

Finally, a word about alcohol. In Macbeth, Shakespeare wrote of alcohol ‘Lechery it provokes and improvokes. It provokes the desire but takes away the performance.’ Clearly alcohol reduces inhibitions, causing Ogden Nash to note ‘Candy is dandy, but liquor is quicker.’ Scientific research has shown alcohol raises testosterone levels in women — a hormone linked to libido in both sexes.

A great variety of odours have been found to increase penile blood flow, including liquorice, lavender, and pumpkin pie.

Alan W. Cuthbert

See also impotence; libido; sex hormones.