Cannibalism: A Perfectly Natural History(60)

Of course I kept on reading.

Throughout the article there were quotes from several women, each of whom was enthusiastic about having consumed her own placenta. “Perfect,” “beautiful,” “precious,” gushed one woman who had tried it. I also learned that while some moms preferred their placenta raw, others favored placenta-flavored smoothies, placenta jerky, and even a particularly apt version of a Bloody Mary. For those turned off by the idea of turning their placentas into a food item, or even handling the organ themselves, there were professional placenta-preparers who could be hired to procure the placenta from the hospital or accept its delivery by mail. These folks would then transform it into a bottle of encapsulated nutritional supplements, thus placing the whole placentophagy experience on a par with popping a Flintstones vitamin (that is, of course, assuming the character-shaped pills were actually made out of Pebbles or Bamm-Bamm). On that note, the article included a handy section (more color photography) for those readers wondering how these “happy pills” were made.

STEP 1: DRAIN BLOOD AND BLOT DRY . . .

STEP 5: GRIND IN BLENDER AND POUR PLACENTA POWDER INTO PILL CAPSULES.

From a biological viewpoint, the first question is, obviously, what is the function of a placenta? As a zoologist I was interested in determining what other mammals (besides white middle-class Americans) ate their own placentas and why they did it.36 There were claims from some midwives and alternative-healthcare advocates extolling the therapeutic benefits of placenta consumption. What were these supposed benefits and, more importantly, was there any proof that they existed? I was also interested in determining whether additional human body parts had been (or were being) ingested for medicinal reasons. Finally, there was the question that had been worming around my brain from the very moment I’d finished the Abrahamian article: What did placenta taste like? Given its bloody, glandular appearance, my initial guess was calves’ liver.

As it turned out, I was wrong.

But first things first.

Advocates of placentophagy are likely to find it more than coincidental that the word placenta is derived from the Greek plakous, or “flat cake.” The Latin term placenta uterina, or uterine cake, was coined by the Italian anatomist, Realdo Colombo. Tempering any culinary-related enthusiasm is the likelihood that the 16th-century scientist was referring to the flattened or slab-like nature of the roughly discus-shaped organ and not its potential as a base for chocolate frosting and candles.

The placenta is the organ that gives more than 9 out of 10 mammals (or roughly 4,000 species) their name—placental mammals. Also known as eutherians, the oldest placental mammals date from around 160 million years ago. Mouselike, they generally kept out of sight while the dinosaurs ran the show. But using their relatively larger brains and enhanced thermoregulatory abilities, they carved out slender niches of their own. Then, approximately 65 million years ago, as the planet underwent cataclysmic environmental changes (including those initiated by a six-mile-wide meteor striking near the current Yucatan Peninsula), the mammals hunkered down and survived. Once the dust settled, and many of our favorite kiddie toys had taken on new roles as fossils, the mammals exploded in diversity, speciating and spreading rapidly across a planet suddenly filled with evolutionary opportunity—a.k.a. open jobs.

Within approximately 10 million years of the dinosaurian demise, mammals diversified into all of the existing mammalian orders—rodents, bats, carnivores, primates, etc. Some took to the air while others returned to the water—each group evolving and passing on its own suite of adaptations, like wings or fins, to supplement basal mammalian characteristics like hair and bigger brains. Many of these species went extinct themselves. Others thrived, eventually outcompeting many of the non-mammalian vertebrates that had also survived the great die-off. And except in isolated regions like Australia and South America (which were effectively isolated from the expansion of the terrestrial placentals), the eutherians even outcompeted the older, non-placental mammals—the marsupials and the egg-laying monotremes.37

The organ that gives placental mammals their name is transient in nature, undergoing its entire rapid development only after conception. The tissue is derived from the fetus, as opposed to the mother, and in humans it has an average diameter of about nine inches. Thickest at its center (up to an inch), it thins out toward the edges and weighs in at just over a pound. The placenta functions as an interface between the mother and the developing fetus, connecting it to the mother’s uterine wall but acting as a buffer as well. The organ itself is richly vascularized, which gives it its dark reddish-blue to crimson color, which relates to the placenta’s life-support function: carrying oxygen and nutrients from the mother to the placenta and then from the placenta to the fetus via the umbilical artery. Structurally, most of the placenta is composed of cells called trophoblasts, which have a dual role. Some form small cavities that fill with maternal blood, thus facilitating the exchange of nutrients, waste, and gases between the fetal and maternal systems. Other trophoblasts specialize in hormone production. Waste products and carbon dioxide travel from the fetus back to the placenta via the umbilical vein. A sheath of connective tissue binds and protects both umbilical vessels, and together the entire structure is known as the umbilical cord.38



The placenta has additional functions, which include the production and release of several hormones, including estrogen (which maintains the uterine lining during pregnancy) and progesterone (which stimulates uterine growth as well as the growth and development of the mammary glands). It also prevents the transfer of some, but not all, harmful substances—bloodborne pathogens for one—from the mother to the developing fetus. Finally, the placenta secretes several substances that effectively cloak the developing fetus from the mother’s immune system—similar to the way in which immunosuppressant drugs prevent the body from rejecting a transplant.