(CNN) Sautéed or blended into smoothies raw, the placenta is becoming an increasingly popular side dish for women after childbirth who are hoping it will help boost their energy and mood.
Some new mothers have the organ -- which develops in the uterus during pregnancy -- dehydrated and put into capsules that they can take in the weeks to months after giving birth.
Although placenta consumption has been recommended since at least the 1500s -- in ancient China, it was mixed with human milk as an antidote for exhaustion, there has been a resurgence in the practice in the last several decades, and especially in the last few years, in the US, Canada and Europe. It has been embraced by celebrities including January Jones and Alicia Silverstone.
Eating placenta purportedly offers new mothers numerous benefits: preventing postpartum depression, reducing pain and postpartum bleeding, increasing breast milk production and improving mother-infant bonding. Yet, very few studies have actually examined what kind of advantage the practice gives women, such as by comparing outcomes like mood between women who ate placenta and those who did not.
An article published Thursday in the Archives of Women's Mental Health surveyed the research to determine what can really be said about the benefits and risks of placenta consumption.
"I had started to have more postpartum and pregnant patients asking whether placenta capsules would interfere with the antidepressants they were taking (or thinking they would probably take after childbirth) for postpartum depression," said Dr. Crystal Clark, a reproductive psychiatrist and an assistant professor at Northwestern University Feinberg School of Medicine who co-authored the new article. Postpartum depression affects one in seven women and, as Clark explained, women were interested in supplementing antidepressant medications, which have been demonstrated to be effective, with the holistic therapy.
"When I first heard of this, my thought was, 'What is the placenta capsule?' That really got me thinking about this and how I can inform my patients about the benefits and risks," Clark recalled.
What Clark found was that there are "no good data" either for or against the therapy, Clark said.
Clark and her colleagues set out to look at all recent studies that addressed why women choose to consume their placenta, how it affects their health and what can be gleaned from studies that replicate the practice in lab animals such as rats.
For as long as placenta consumption has been practiced, Clark and her colleagues found only 10 studies that examined placentophagy, its technical term, published between 1950 and 2014 that could help answer their questions. One of the earliest mentions that the researchers found of mothers eating their placentas for health benefits was actually in a 1977 "Saturday Night Live" skit, Placenta Helper.
Among the academic reports of placentophagy, a small 1954 study found that 86% of mothers who ingested freeze-dried placental tissue said they felt "good" or "very good" in terms of their milk production. However, as Clark and her colleagues pointed out, this study did not look at the effects in women who did not consume placental tissue and whether their milk production was also improved. In a more recent 2013 study found, based on an Internet survey, 40% of mothers reported being in a better mood, which was the main reason (34%) they gave for eating their placenta.
The strongest evidence for a benefit of placentophagy, Clark said, comes from a series of experiments that found that lab rats that eat their placentas immediately after giving birth appeared to have less pain. However the way the placental tissue was prepared and consumed in these studies was different than what is typical in people. "It has been suggested that the pain-mediating factor was very sensitive to temperature, and would not last more than 24 hours at room temperature" whereas placentavores usually eat the tissue later, or do not keep it cool enough to preserve this factor, Clark said.
Despite the lack of strong evidence yea or nay for placentophagy, Clark does not necessarily recommend against the practice for her patients. "I just inform them that it might not do anything, but it's definitely her choice," she said. However, she said, "I would not recommend at this time that a woman forgoes iron capsules or antidepressants or other treatments for which there is evidence of benefit."
Going forward, Clark thinks there needs to be research on whether potentially beneficial components, such as estrogen, opioid and the "love hormone" oxytocin, are even present in raw placenta, as well as potentially harmful substances such as mercury, lead and bacteria. "We know that the placenta captures toxins," Clark said.
Sarah Moore, an independent perinatal counselor and childbirth educator in Brooklyn, New York, said that she is "very clear" that evidence in support of placentophagy is anecdotal, but she said "there is really good anecdotal evidence that people feel good doing it."
Moore makes placenta capsules for the women in her childbirth classes and for the doulas she works with. In the last few years, Moore said there has been an uptick in interest in the capsules. "There's been some celebrities talking about it and quite a few articles in mothers' magazines and online parenting groups looking at it," she said.
Moore charges $275 to make one placenta into 80 to 200 capsules (depending on the size of the placenta). She recommends women take two capsules three times a day for two weeks or more if they feel it is benefiting them. The process involves steaming the organ, dehydrating it "until it's really crispy almost like beef jerky," crushing it into powder and putting it into gel capsules, Moore said.
Although she mixes in ginger, lemon and red pepper, Moore said those ingredients act like preservatives and the capsules themselves don't really have any flavor.