The Enigma of Placentophagia: To eat, or not to eat?

On monday, we had our second visit with the Doula, Jessica, to go over medical history, concerns, and things to think about over the next few months. Over the course of our talk, Chris revealed to Jessica that one of his biggest fears was that I would have terrible post-partum depression (PPD) after the baby was born (Except, he didn't say it like that, instead he said, "I'm afraid that she will go crazy". Isn't that adorable?). So, here's the crazy thing, Jessica asked if we had considered encapsulating the placenta after birth. To which we replied, "What the heck is that, and what does it have to do with PPD??". Very briefly, placental encapsulation in when the placenta is carefully dried out after the birth, pounded into a fine powder and then encapsulated into pill form. The idea is that your hormone levels go totally wacky aftery you give birth. So, you take these placenta pills in the few weeks after birth and the hormones and other substances even out your hormone levels and this is thought to reduce PPD, stimulate milk production, and generally just be good for you.

You probably have the same incredulous face that I had when I first heard of this idea. Needless to say, I COULDN'T WAIT to blog about this topic. Is this practice weird pseudoscientific crunchy granola hippy crap? Or is it an adaptive evolutionary behavior that has been lost in modern human society to the detriment of women and babies worldwide? The debate is fascinating, please read on.

The most striking piece of evidence in this debate is that almost all mammals immediately consume the placenta and amniotic fluid that is delivered during birth. This behavior is called placentophagy. This behavior is exhibited by rodents, cows, carnivores, horses, primates, apes, etc. etc. There are very few exceptions to this rule (e.g. aquatic mammals do not eat the placenta, and marsupials reabsorb the placenta rather than delivering it, and therefore cannot eat it). This behavior is remarkably evolutionarily conserved. Even our most closely related relatives, the higher non-human primates and apes, universally display placentophagy. In all of recorded anthropological studies, however, there is no mention of humans eating placentas. In modern cultures where what happens to the placenta is known, the placenta is usually burned ceremoniously (or unceremoniously, as the case may be). Or it may be buried to fertilize a tree, and the fruit produced by the tree is eaten. Or a piece may be dried and saved as a talisman. Other cultures, like in china, the placenta is dryed and used in traditional medicines. There is no recorded history of direct placentophagy in humans similar to what is displayed by animals (Ober 1979. Bull. N.Y. Acad. Med. 55;6, p591-599).

The lack of a mention of placentophagy in our most ancient writings isn't neccesarily proof that it did not happen. Birth practices have traditionally been shrouded in mystery. In fact, there is very little recorded history about birth, in general. Interestingly, the most direct references to the fate of the placenta is in strict taboos against eating the placenta. For example, in the bible, Deuteronomy (Chapter 28), there is detailed descriptions of the good things that will happen if the Israelites follow the laws and statutes of God, and the horrible punishments that will befall them if they choose not to do so. Verses 52 to 57 describe how if the people were to disobey God, the men will practice cannibalism and the, "tender and delicate women among you will consume the afterbirth for want of [more appropriate food]" (Ober 1979). The fact that this was considered taboo, indicates to me that there may have been tribes of early pagans that practiced placentophagy and early religions seized on the practice as a way of separating God-following humans from other animals (or to place other humans that did not follow that particular God on the same level as animals). This would not be the only example of a common practice being arbitrarily banned by "God". It seems that God bans things as a convenient way of separating in-groups from out-groups (eating pork, leaving your head uncovered, homosexuality, to name a few). If these speculations are true, it is possible that very early humans did practice placentophagy before the beginning of recorded history and have since lost the practice. I tend to think this is a likely scenario, given our common ancestory with primates, which would lend credence to the evolutionary argument for placentophagy, but this is very difficult to prove.

So regardless of the human question, to which we will return to later, we still have the enigma of almost universal consumption of the placenta by all other mammals. Why would any mammal eat the placenta? There are a few hypotheses to explain placentophagy. [I'm paraphrasing from a review written by Mark B. Kristal in Neuroscience and Behavioral Reviews (Vol. 4, p141- 150, February 1980).] The main explanations are that 1) mammals consume the placenta simply because they are hungry after the exertion of giving birth and need the extra nutrition, 2) the placenta is consumed to remove it from the nest where it might attract predators, and 3) the mother is responding to specific nutritional or hormonal needs that are satisfied by consuming the placenta. The hunger hypothesis is relatively easily disproved by the fact that given a choice between placenta and a variety of other foods shortly before birth and immediatly after, rhesus monkeys will exclusively eat the placenta. Similar behavior is found in rats. The prevention of predation hypothesis is attractive, but is also easily argued against. It still doesn't explain why the mother would eat the placenta. Why not bury it? or move away from the site of the birth? Or, in the case of tree-dwelling monkeys, why not drop the placenta out of the nest to the ground far below? Instead, tree-dwelling monkeys will keep the placenta around for a while and take an hour or two to finish eating it. In addition, mothers that have little risk of predation will also enthusiastically eat the placenta.

This leaves the third hypothesis, that for some reason, the placenta becomes extremely attractive and tasty to the mother immediately before or during birth, likely for evolutionary reasons, in which mothers that ate the placenta produced young that survived better than mothers that shunned the placenta, thus conserving the trait. The reasons that placenta-eating might be evolutionarily adaptive stem from the fact that the placenta contains a variety of hormones, including progesterone, estrogen, and prolactin that have positive effects on the mother and/or babies. Studies show that ingestion of the placenta has a profound effect on the production and presence of these hormones in the blood of the mother. In one study, pregnant rats were either allowed to consume the placenta or the placenta was removed before the mother could consume it. Mothers that were prevented from eating the placenta showed a dramatic increase of progesterone levels on days 6 and 8 following birth. On the other hand, mothers that were allowed to eat the placenta maintained relatively steady levels of progesterone, they also showed an early boost of prolactin production that was absent in the non-placenta eaters (Blank and Frieson 1980. J. Reprod. Fert. 60, p273-278). These results are relevant because the fluctuation of progesterone levels following birth is hypothesized to be a risk factor for the development of PPD in humans. Also, an early boost of prolactin, a lactation hormone, could stimulate more efficient milk production in the placenta-eaters. In another study, when foster rat pups were given to a lactating female they had a much better chance of surviving when the placenta was still attached, presumably due to the beneficial hormonal effects of consuming the placenta in the mother (Deneberg et al. 1963. J. Reprod. Fert. 5, p131-141). More recent work from Kristal's group at the University of Buffalo shows that placentophagy in rats enahnces opioid-mediated pain suppression (DiPirro et al., 2004. Brain Research) and opioid activity in a certain part of the brain, in addition to suppressing pain, also stimulates maternal behavior (Neumann et al. 2009, Brain Research). These data, although limited mostly to rats, indicate that placentophagy can alter hormone levels and prodcution, induce maternal behaviors, increase lactation, and suppress pain. Even with all these beneficial effects, there doesn't seem to be an enormous deficit in maternal behavior if the placenta is removed before eating, indicating that it is not an essential factor in proper rearing of pups. Nevertheless, there do not seem to be negative effects associated with placentophagy.

If you have read up to here, I applaud and thank you! Annnnd you are probably thinking, "OK, now what about all the human studies?"  There are none. There are absolutely zero studies where placentophagy has been studied with any sort of rigor in humans. Ok, there is one study, but it's somewhat fluffy, according to Kristal:

"In 1954 a group of women that had recently given birth were fed disguised freeze dried placenta [the women did not know that they were ingesting placenta]. Apparently, 86% of the subjects showed improved milk production and flow, whereas among control subjects, fed beef treated identically to the placenta, only 33% showed improvement. Further more, the authors classified more than a third of the placenta-improved subjects, but none of the beef-improved subjects, as having an "extremely strong" positive reaction. (Soyková-Pachnerová et. al., 1954. Gyneacologia, 138: 617-627"

Even with this relative lack of human-based studies, there is an extremely vocal and adamant movement towards encouraging placentophagy in humans. This is not all fringe either, it has even been popping up in USA today articles! These people, like my Doula, believe that consuming placenta pills after their birth prevents depression, enhances milk production, and makes them feel better. The personal testimonials are very interesting. Momaroo talks about her first experience with Placenta pills. She says that after the birth of her first children, she had debilitating PPD, but with her most recent pregancy, she has had much better symptoms. She says that even with being sleep deprived she feels cheerful and maternal, which is a complete turn-around from how she felt in the weeks following her first births. Of course these testimonials don't prove much of anything, but I doubt these women are lying about their personal experiences. Perhaps there is some sort of placebo effect that reduces the PPD? There is no way to know without randomized, controlled studies. My question is that with PPD being such a prevalent and horrible condition (almost 25% of women will experience moderate to severe PPD), why isn't this easy and inexpensive solution being taken seriously?

I would love to see continued research done on this. The animal data is encouraging, but this topic is vastly under researched. I have trouble believing that mere yuckiness factors and general prejudice against natural birth practices would prevent science from moving forward on something so important!