Uncovering the Truth About Bacteria and Heavy Metals in the Placenta

Uncovering the Truth About Bacteria and Heavy Metals in the Placenta

Recent news stories, blog posts, and online articles have claimed that “science fails to see benefits of eating placenta.”¹ Many of these articles have been fueled by papers published by researchers at Northwestern University. Courtney Durfee of the Association for the Placenta Arts Preparation (APPA) gave a thoughtful review to the two papers, viewable here.

Some of these articles include forceful concerns of heavy metals and harmful bacteria.  A recent NY Times article states that “….the placenta is not sterile, and several studies found that the organ was contaminated with bacteria as well as selenium, cadmium, mercury and lead.”¹ The article links two NIH studies as references, we will address both along with taking a deeper look at these worrisome statements.

We should begin with talking about how the placenta works and some of its roles to the mother and fetus.  The placenta is often referred to as a filter; this isn’t an ideal term for the placenta considering its function in the body. As consumers we use filters in daily life to remove unwanted particles and toxins then throwing them into the trash once they have reached capacity.  The placenta does not function as a filter in this sense, a more suitable way of viewing it would be as a gatekeeper between the mother and fetus.  The placenta’s job is to keep the maternal and fetal blood separate, at the same time allowing nutrients to pass to the fetus, gas exchange to occur, and allowing waste from the fetus to pass through to the mother.  The placenta does prevent some toxins from passing through to the fetus but they are not stored in the placenta.  Toxins in the body and waste from the fetus are processed by the mother’s liver and kidneys for elimination.

Now that we have a better understanding of how the placenta works lets take a look at “the heavy metals found in the placenta.”  The NIH study linked in the NY Times article reviewed past studies of mercury, cadmium, and lead levels found in the placenta worldwide.²  For a better understanding of what the data means we will focus on the most recent numbers listed for the United States.  Starting with mercury, the review did not find a notable amount of mercury in the placentas of mothers giving birth in the US.  Next, cadmium levels in the US showed an average of 4.4 ng/g with the highest levels reported from urban areas and levels two to three times higher amongst women who smoked during the pregnancy. The average placenta weighs 550 g, which would result in an average of 2.42 µg of cadmium in the entire placenta.  The FDA does not regulate the levels of cadmium in food products.  According to the European Food Safety Authority the average adult can consume 170 µg of cadmium per week safely, which is approximately 24 µg a day.³ So even if the mother were to consume the entire placenta in one day, the amount of cadmium would be significantly lower than the amount deemed safe by the EFSA.  Lastly, the most recent US study in the review shows lead levels in the placenta averaging 5.1 ng/g.  For a bit of perspective about what this number means, the FDA recommends that the level of lead should not exceed 100 ng/g in candy.4   Note: the NY Times article states that selenium is also found in the placenta, the linked research article did not take a look at or review any studies that referenced selenium.  Selenium is not a metal; it’s a mineral and one that is shown to have positive effects on the body and developing fetus.  A study conducted in 2012 showed a correlation between delivering SGA infants (small-for-gestational-age) and lower levels of selenium in the placenta.5

These three metals cross the placental barrier to the developing fetus and also once the baby is born through breast milk. The consensus amongst medical professionals is that the benefits of an infant consuming breast milk greatly outweighs any risks that these heavy metals may or may not have on the developing infant.6  These heavy metals are a part of our environment, foods, and have become something that our bodies contain.  One could also suggest that the benefits of placenta consumption outweigh any minimal risks to the mother.

Now, lets address “the placenta is not sterile and is contaminated with bacteria.”  Yes, the placenta is not sterile, no part of our body is.  There are very few things that exist in the world that are sterile and they are often created by man to be this way for a short period of time.  Our world is full of bacteria, many of which are beneficial.  In a study, also funded by the National Institute of Health, Dr. Kjersti Aagaard of Baylor College of Medicine states “the infant is exposed to several environmental sources of bacteria in the early neonatal interval through the maternal vaginal canal and feces, swallowing and breathing, skin to skin contact, maternal breastmilk, etc.”  She reports that exposure to the bacteria during and immediately following the birth process is beneficial to building a microbiome.7   Some believe this process is so vital that researchers are now studying the use of vaginal swabs to ‘seed’ babies born by C-section and telling new moms to skip that first bath on the day of birth.   So yes, your placenta and baby have been “contaminated” by the bacteria in and around your vagina during birth.

There are lots of good this bacteria exposure can do, can some bacteria that the placenta is exposed to be harmful?  While there have been no research findings that suggest there are harmful bacteria routinely contained within the placenta prior to birth, it is possible that the placenta can come in contact with bacteria that may pose a risk for illness if consumed.  If opting to have your placenta encapsulated it important to find a Certified Placenta Arts Specialist trained in Food Safety.  Just like with the foods we eat, proper handling, storage, and processing are key steps to the mother’s safety.  There are times when its not advisable for a mother to consume her placenta, such as when an intrauterine infection is present, and these concerns should be discussed with their doctor or midwife at the birth.

We agree whole-heartedly that more research about human placenta consumption and encapsulation is needed.  We are excited to know that there will be more information available in the coming years.  In the meantime, we hope to see more news articles that are not fear-based but focus on education.  Information that supports mothers wishing to consume their placenta, to keep any risks associated minimal and that reinforces the proper steps for safety.  We encourage women to do their research and ask qualified professionals questions to ensure that they are making informed decisions about their care and the handling of their placenta following the birth.

Post written and researched by Nikole Keller of APPA


  1. http://well.blogs.nytimes.com/2015/06/09/science-fails-to-see-benefits-of-eating-placenta/?_r=1

  2. http://ehp.niehs.nih.gov/1204952

  3. http://www.efsa.europa.eu/en/efsajournal/pub/1975.htm

  4. http://www.acs.org/content/acs/en/pressroom/presspacs/2014/acs-presspac-september-3-2014/lead-and-cadmium-found-in-some-chocolate-bought-in-brazil.html

  5. http://onlinelibrary.wiley.com/doi/10.1111/j.1740-8709.2012.00430.x/abstract

  6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569122/

  7. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0036466

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