Is metaphor at play in the use of such things as hak'achu, quinoa, and askantuy larvae for increasing milk production in Ccachín? If so, what associations are made? Metaphoric connections are specific to the salient features of the items being compared, but taken together, there may be patterns.
One possibility is suggested by the milk-white brew made from askantuy larvae. Quinoa broth likewise has a white, creamy appearance. Color enters into humoral classification, and it may be metaphorically important in this context as well. Victor Turner suggests that the colors of red, white, and black universally signify blood, milk or semen, and feces respectively, with perception of the world referenced to what we subjectively know best – the human body . The contrast between white and red in several of the techniques used to suppress lactation in the Andes is intriguing in this regard (Table 2). Color alone, however, would not seem to sufficiently narrow the range of available alternatives. The milky-white secretions of pampa llank'u (milkweed), kiska qhana (sow thistle), and wach'anka (Euphorbia huachangana) are also put to medical use in Ccachín, but none of them are believed to enhance a woman's milk production. Pampa llank'u is rubbed on one's legs and other extremities when they hurt from the cold, kiska qhana is used as a tea for heart pain, and the milky liquid obtained from wach'anka makes a purgative used to treat drunkenness and a pesticide for rats and mice. Notably, however, thistle tea is used as a folk remedy for stimulating milk production in the U.S. .
A second possibility is that the qualities of wet and dry are salient. The dried hak'achu remains are reconstituted and served as broth. Drying and rehydrating are commonplace operations in the Andes. The Inca mummified their deceased rulers, and pre-Incan peoples are still believed to exist through their bones and mummified remains. Dried llama fetuses are "purified by the sun" and served to the mountain spirits [17, 18]. Potatoes are frozen and sun-dried as ch'uñu, where they are conceived as having an ambiguous "life-in-death" state of being . Meat is sun-dried as charki (a Quechua term that has made its way to the English language as "jerky"), and both ch'uñu and charki are reconstituted in water before serving. Villagers in Ccachín say that one should not throw corncobs out the door because the person who throws them out may swell up in the rain and dry up in the sun as the cobs do. The sympathetic associations have the effect of reinforcing a practical injunction in this case, as corncobs are used as scrub brushes, knife handles, and fuel for fires.
Both ch'uñu (freeze-dried potatoes) and khaya (freeze-dried oca) served in soups are used in one area or another of the Andes as galactagogues. The act of transforming ch'uñu, hak'achu, quinoa, and other galactagogues from a dry liminal state to a hydrated, life-giving one may be sympathetically linked to the hoped-for pattern in the breast. In reverse, when a woman needs to suspend lactation, a bit of milk from her breasts is swabbed in a wad of cotton and set out in the sun to dry (Table 2) [4, 7]. The logic of dehydration and reconstitution doesn't explain why hak'achu carcasses are used as galactagogues rather than those of the chiwanku thrush (Turdus chiguanco), however, or why quinoa is used instead of wheat or corn, so it cannot provide a full explanation of the practice.
The hak'achu is not the only bird dried and used for medicinal purposes in the Ccachín. The Andean condor scavenges carrion and soars on the winds sweeping up the east flank of the Andes. Correspondingly, it is associated with illnesses and death caused by the malevolent machu wayra winds (see Table 3). Condor feathers are toasted, ground, and brewed in the same manner as hak'achu. The broth or tea is used to treat respiratory diseases. One of my comadres made just such a tea from a single condor feather for her aging mother when the latter was gravely ill. Hummingbird carcasses are also dried and used in the Cusco area. With its rapid, blurry movement, the hummingbird is considered to be a messenger bird, usually an omen of death. Allen, for example, recounts an encounter with a hummingbird that was interpreted by her informants as portending the death of her grandmother . A soul may leave the body to visit faraway relatives through the medium of a hummingbird, especially during the eight days that the spirit stays near the family after a person's death. The roasted carcass of the hummingbird is used in treating fright in children and soul loss, and it may be substituted for condor feathers in some treatments when the latter are unavailable . The flesh of the chiwanku thrush is used in the Department of Huánuco for jaundice and other liver ailments. A metaphorical association between illness and treatment is suggested in this instance by the frequency with which this bird discharges its excrement .
Given these and other associations based on the perceived traits of birds (the use of the talons of black-chested buzzard eagles, for example, is described in Table 3), it seems equally plausible that there is some trait of the Andean flicker that establishes a metaphorical association with milk or lactation. Hak'achu flesh is used as a meat in soups and stews in the Cusco area . Hak'achu blood is mixed with wine to treat heart problems, dropped in the ear to counter hearing loss caused by the wind, and taken as a drink to combat tuberculosis [4, 7, 13]. The feathers are used for cleaning teeth . In some areas of Cusco, a hak'achu's tongue is carried as a charm to help one find love . In Andean lore, the hak'achu carries the leaf of a secret plant in its beak to soften rock while boring its nest [7, 13, 20]. Perhaps because of this tenderizing effect, it's said that a woman pecked by the beak of a flicker will thereby become an adept and appreciated cook.
Tradition has it that the Inca learned the secret of this herb from watching the hak'achu, and applied it in their monumental architecture . In the 17th century, Padre Antonio de la Calancha wrote that thieves and delinquents at Potosí (Bolivia) used the herb to dissolve stone and metal bars to escape from the jails . Venero Gonzales  reports that the plant is often said to be manka p'aki (Eupatorium peregrinum, Eupatorium sternberginianum), which translates as "broken pot," further extending the metaphorical connections (manka p'aki also is used as a galactagogue in its own right in the Arequipa area). I suspect that this association of the bird with a magic herb traveled with the Spanish from Europe, where certain woodpeckers were believed to use moonwort (a fern) or "springwort" (an herb unknown to humans) to dissolve the materials people used to plug their nests with. The springwort legend appears to originate even further east, where it appears in the Arabian Nights, the Koran, and the Talmud . The association could have been reinvented in various cultures many times, however, from watching the behavior of the birds.
While there are several kinds of woodpeckers in the Andes, they have enough in common that beliefs seem to pass readily across species boundaries. Elsewhere in Peru, the heart of a woodpecker is added to wine to treat epilepsy, and the feathers are used in treatments to prevent spontaneous abortion and facilitate delivery . The association between woodpeckers and childbirth is notable, and the metaphoric connection to softening objects and opening/closing passages is clear.
The association between hak'achu and milk production has not been explained by my informants, for whom it is common knowledge and taken as a given, and the logic is not obvious to an outside observer from the characteristics of the bird. The bird's tongue, red nape, audible call, association with rocky terrain, and habit of making holes are the features highlighted in stories about the bird. The hak'achu favors the high puna grasslands where people pasture their cattle, although it's not the only bird to do so. The association with cattle, however, extends as far south as Argentina, where it is likewise considered to be the enemy of cattle rustlers. There may be a good practical reason: it is said that when thieves move among the herds, it alarms the birds and their calls warn the herders .
While humoral medicine is practiced in Ccachín with both humans and animals, and the hot/cold classification system central to it in part is metaphorically derived, I never heard the effectiveness of hak'achu explained in terms of its hot/cold properties. Several of the criteria used in hot/cold classification in the Andes would potentially apply to the use of flicker remains as a galactagogue, and it remains to be seen if it is interpreted in such terms in other Andean communities. The hot-cold classification system has its origins in the humoral theory of the Old World, where it was the protoscientific doctrine of the medical establishment at the time of the Spanish conquest, and it continues to be practiced throughout Latin America, especially in the mountain regions [23–25]. Ethnomedical practices in the Andes have various origins, both pre- and post-conquest, and many of these bits and pieces have gradually been integrated into the humoral model, serendipitously in some instances, assimilated by the model in others . But there is no attempt to integrate many practices, and they maintain a logic all their own.
Metaphorical associations aside, the question remains whether the techniques used in Ccachín to stimulate the flow of breast milk have the consequences ascribed to them, and if so, whether they are more likely to lead to the desired outcome than available alternatives.
Hundreds of plants are used as galactagogues worldwide, but the biochemical actions of only a few of them have yet been investigated. Some of those investigated have been found to have estrogenic, oxytocic, or other hormonal effects in lab conditions . Notably, the pharmacologically-active constituents of fennel – sometimes added to the corn-salt mix given to cows in Ccachín to promote milk production and used for the same purpose by women in some areas of Peru – are dianethole and photoanethole, polymers of anethole. Anethole is structurally similar to the catecholamines, which are believed to influence secretion of prolactin . In one study, fennel oil increased milk production and the milk's fat content for goats . On the other hand, mint (Mentha spp), also sometimes added to the corn-salt mix given to cattle in Ccachín, may reduce or dry up the milk supply in both humans and animals when taken in sufficient quantities [29, 30].
While there are not many data on the incidence of lactation failure in humans, it is considered to be rare, especially relative to the amount of cultural concern given to it in many societies [12, 31]. The critical importance of successful breast-feeding through human history has apparently selected against poor milk producers . The lactation process involves mother-infant interaction, and failure may be caused at either end. The infant's sucking affects the quantity of milk produced, and a variety of sucking and swallowing disorders (prematurity, cleft palate, etc.) can affect milk production. Given the importance of sucking, some have suggested that the spread of bottle-feeding and widely-spaced, scheduled breast feedings has led to an increased incidence of "insufficient milk syndrome" – real or perceived milk insufficiency . This pattern is most common in industrialized urban areas, but unlikely in Ccachín, where the single case of bottle-feeding I witnessed was for an infant whose mother had died soon after childbirth. There are anatomical, hormonal, nutritional, and pharmacological causes that can affect both the production and release of milk, but the literature has predominantly emphasized psychosocial interference with the release of milk, the so-called "let-down reflex" .
While unknown pharmacological effects of some of the galactagogues used in Ccachín can't be discounted, the effects of hak'achu broths, quinoa broths, and others as fluid supplements, as nutrient supplements, and as reassurance on the let-down reflex are the most probable and the best understood.
A positive relationship between milk production and drinking fluids is often hypothesized. It's also backed by anecdotal evidence. A woman I rented a room from in Cusco, for example, reported noticing a difference in her own milk flow depending on her fluid intake. Various investigators, however, have found that variation in water intake within wide limits has no physiological effect on the volume of milk produced, and this is consistent with the anti-diuretic effects of prolactin, one of the principal controlling pituitary hormones . The widespread belief that fluid intake affects milk yields emerged either as a response to extreme conditions (severe enough to affect health in general), or is another instance of likeness substituting for correlational likelihood (fluid in, fluid out). As Orlove notes, the rural Andean practice of serving boiled soups and stews in the early morning and late afternoon has the adaptive benefit of providing sufficient water to avoid the risks of dehydration in the dry season, while reducing the danger of ingesting parasites from contaminated water sources . These preferences seem generally sufficient in themselves to ensure that a nursing mother receives enough fluids. In any case, the belief in the importance of increased fluid intake while lactating does not explain why particular broths are considered more effective in stimulating milk production than others.
A common thread linking many of the galactagogues in Ccachín is their high protein content. Quinoa averages 16% protein by weight, compared to 8–12% for corn, the staple cereal in Ccachín. Its protein quality is close to the FAO standard, comparing well with milk and meat. Quinoa is high in such essential amino acids as lysine and tryptophan . Corn, on the other hand, is notably deficient in these limiting amino acids. Hak'achu has been hunted for its meat since Incan times, if not before, though in Ccachín its use is exceptional and it is not thought of as a game dish. Askantuy larvae are used medicinally rather than as a food source, but another larvae, wayt'ampu (Metardaris cosinga) is recognized for its nutritional value and is said to be a brain food .
The maternal causes of lactation failure and the effect of dietary supplements are not well understood. Studies of the lactation performance of both well-nourished and malnourished women in recent years have found a surprising consistency in daily milk volumes, and it appears that physiological mechanisms exist to compensate for inadequate maternal nutrient intake, with cumulative long-term nutritional cost born by the mother . The threshold level below which a woman is unable to produce a normal quantity of milk appears to be quite low. One study in Gambia found that there was no significant decrease in milk volume when caloric intake fell to 1200 kcal/day, 70% of the women's average consumption. One of the best studies we have of the seasonal fluctuation in caloric intake in the Andes, conducted in Nuñoa (Puno) in 1985, shows a fluctuation of between 1250 calories pre-harvest and 1900 calories post-harvest for women in their childbearing years . This is above the 1200 kcal/day threshold, though whether this threshold holds in a high mountain environment is an open question. On the other hand, studies in Nigeria and India have shown significant increases in milk output when women are given a protein supplement increasing their protein intake from 50–60 grams/day to 100 grams/day . According to one of the most comprehensive nutritional studies we have for the Southern and Central Andes, the Encuesta Nacional de Consumo de Alimientos of 1971–1972, annual per capita calorie and protein consumption for households that consumed primarily traditional foods varied from 2045 calories and 56 grams of protein/person/day for low income households to 2716 calories and 83 grams of protein/person/day for high income households . However, these statistics are for adults of both sexes combined, and valuable as they are, a one-year study does not adequately capture the susceptibility of highland populations to environmental fluctuations.
As with the quantity of protein, the quality of protein and non-protein nitrogen compounds in the milk may be affected by maternal nutrition under threshold conditions, but the effect seems to be minor in magnitude. Most studies show that the protein content of human milk is relatively constant regardless of maternal nutrition . Overall then, existing research on the effect of maternal nutrition on milk volume is inconclusive, with limited evidence that substantial protein supplements can affect milk production and supplements of protein and vitamins can affect milk quality under certain conditions. Given our current knowledge, it seems unlikely that traditional high-protein food supplements for nursing mothers in the Andes can be related to any observed increases in milk production, except perhaps at certain undetermined threshold conditions. Such supplements, of course, promote good nutrition, and in so doing, prevent illness, fatigue, and general states of unwellness that can stress and strain long-term nursing. The cumulative deterioration of nutritional status through maternal depletion can shorten the lactation period .
Unlike areas of the world where dietary taboos while nursing severely limit a woman's protein intake, dietary practices in the Andes contribute to a mother's general health. Except for quinoa, the local grain with the highest protein content, however, it's hard to explain the specificity of some of the more exotic local galactagogues used as protein supplements. Any domestic or game animal protein should do, and unlike hak'achu and askantuy, many of the alternatives are available in significant quantities. Hirschkind reports that chicken is an indispensable ingredient in the soup prepared during the forty-day post-partum diet used by women in Cañar province of the southern Ecuadorian highlands, and guinea pig soup is consumed by the women of that area during lactation to help them produce plenty of milk as well . Chickens and guinea pigs are not only very ready sources of protein in Ccachín and many other rural villages in Peru as well, they are raised primarily by women. On the other hand, neither hak'achu nor askantuy are consumed as standard fare, and the beliefs about their value as galactagogues may have emerged under conditions of environmental stress.
Psychological and social factors
Under normal conditions, the probable explanation for the positive effect of most milk-producing treatments in the Andes is psychophysiological. Indeed, among health domains, lactation is a sphere where social and psychological factors play an exceptional role. Emotional responses appear to play a key role in the success and failure of lactation in both nursing mothers and dairy animals; so much so that lactation has sometimes been termed a "confidence trick" . Apprehension and anxiety inhibit milk secretion by interfering with the let-down reflex. Sufficient milk is available, but it doesn't reach the infant. Emotional upset triggers a vicious cycle as lactation failure increases anxiety and doubt during subsequent feedings. At the same time, breast engorgement interferes with an infant's ability to suckle and poor milk drainage increases the probability of bacterial infection, all further contributing to lactation failure. The consensus of contemporary Western medical opinion seems to be that most galactagogues work as confidence inducers, reinforcing the let-down reflex.
High-protein animal products are coveted in Ccachín, and the etiquette of their meal-time distribution can influence one's self-esteem and emotional well-being, beyond their positive nutritional effects. People often talk about who gets the most and the best portions of meat in Ccachín. Hak'achu flesh and some other local galactagogues are not served in sufficient quantities to have much impact on general nutritional levels, but have an advantage over more mundane protein sources for emotional impact in their exceptional character. Their specialness and rarity single them out. A parallel can be drawn here to the use of woodpecker-scalp headbands by natives of Northwest California in their Jumping Dance . Such headbands were regarded as treasures and used in shamans' fees, bride prices, injury compensations, and other exchanges. The rarity of the scalps contributed to their value, and the dance gave their owners an opportunity for their public display. The expressive and sociocultural characteristics of the bird's use as a galactagogue could help explain any psychophysiological effectiveness that it has for human populations.