Should Kombucha Have a Place in Your Pregnancy?
A review on the literature of fermented tea consumption during pregnancy.
When strolling the aisles in the refrigerated section of your local Whole Foods or other health food store, you will notice a colorful assortment of glass bottles that have gained recent attention and popularity in the holistic health community — I’m talking about kombucha. Ahh yes, kombucha. The refreshing, effervescent, probiotic “wonder” tea that boasts curative health properties for those who drink it. From Baschali et. al.’s (2017) study substantiating evidence of improved digestion, liver function, and body detoxification with regular consumption, to its supposed ability to eliminate cancer cells. This tea has made its mark in the alternative health sphere, and is only becoming more pervasive. Whether you like it commercially made, or prefer your home brew, accessing this miraculous health elixir is now as easy as taking a trip to the grocery store to buy a bottle or starter kit.
But what exactly is kombucha? What are the health claims? Are there any negative health effects? And, is it safe to consume during pregnancy? By drawing evidence from published literature and studies, I aim to answer all your burning questions on what we know and don’t know about kombucha consumption during pregnancy. (Disclaimer, there is a lot that we do not know about potential drawbacks and/or benefits of drinking kombucha while pregnant.) But, before you click out of this browser, numerous studies in expecting mothers have been performed on certain elements that compose the fermented beverage — such as the fermenting culture (SCOBY, which I will elaborate on later), probiotic content, and low-level alcohol dosage — that may help piece together the narrative of whether it is dangerous to mother or fetus. So, to begin understanding kombucha’s place in your pregnancy, I will start by answering the initial question: what exactly is kombucha?
Kombucha: What is it? How is it made?
Kombucha, a fermented black tea drink, has been culturally significant in the dietary and health practices of most Asian countries for many centuries. The process of making kombucha, at home or commercially, involves combining and fermenting a mixture of black tea, sugar, and a symbiotic consortium of acetic acid bacteria and yeast (SCOBY), then allowing to ferment for 10 to 20 days (Baschali et al., 2017) (Jayabalan et al., 2014) (Nummer, 2013). The SCOBY is the culture responsible for transforming the tea into a healthful beverage. The resulting liquid is a vinegary, semi-sweet beverage that is then drained off and can either be consumed immediately or bottled and stored in the refrigerator for later consumption. For continuous brewing, the SCOBY along with a portion of the reserved liquid can be used to make the next batch of kombucha by combining it with the black tea and sugar mixture. Now that we know what all goes in to the brew and how it is made, lets get in to some of the health benefits that have allowed kombucha such a persistent role in ancient and alternative medicine.
Kombucha: Are there any negative health effects?
As far as negative reports of regularly drinking kombucha, complications like upset stomach or allergic reactions linked to kombucha consumption have been reported, but no longstanding symptoms were observed with the cessation of its intake in these patients (Baschali et al., 2017). Several acute cases of hepatotoxicity and severe metabolic acidosis in the United States were linked to chronic kombucha intake, with one fatality in the 1990’s involving an immunocompromised HIV patient who passed merely 15 hours after consumption (Kole, Jones, Christensen, & Gladstein, 2009). Along this timeline, the Centers for Disease Control (CDC) (1996) released a statement recommending limiting kombucha consumption to 4 ounces per day in response to reports of severe lactic acidosis among two older individuals, resulting in death for one. Of these cases, both consumed a brew they made in-home daily, and both cases were using SCOBYs derived from the same parent (CDC, 1996).
While this evidence may make you write off kombucha for good, there are two important takeaways from these cases of hepatotoxicity and acidosis. The cases described involved both immunocompromised individuals and high levels of chronic consumption. So, if you are immunocompromised, regularly consuming copious amounts of the fermented tea, or both, that places you at a higher risk for these complications. Sticking to the CDC’s recommendations for consumption along with consulting a doctor to validate the capability of your immune system to handle regular intake of kombucha should ensure the safety of exposure levels in non-pregnant individuals. For expecting or new mothers, the best practice would be to take into account the state of your immune system along with that of your unborn fetus or infant in the case that you are breastfeeding. From this evidence, though, despite the maternal-fetal barrier, it could be assumed that direct fetal or infant consumption would not fare well for their health considering their size and underdeveloped immune system.
Kombucha: health claims
Many studies have been conducted on the health benefits of kombucha tea that speak to the positive advantages of consuming it under normal circumstances. A study conducted on the in vitro antioxidant activities of kombucha found that the beverage boasts a high flavonoid content that helps protect the body from free radicals, thus preventing the progress of many chronic diseases and/or cancers (Lobo et al., 2017). This study also compared the antioxidant activity of tea versus fermented tea, and suggests that fermented tea — or kombucha — has a “greater potential as a therapeutic agent than [regular] tea” due to secondary molecular reactions that increase antioxidant activity (Lobo et al., 2017). While herbal tea has historically had a place in holistic and ayurvedic medicine, this study confirms that fermented tea may possess greater health benefits for consumers. Though, unlike herbal teas, fermented tea poses an additional risk due to its acidic makeup and, in some cases, non pasteurization. Much like other health-products, it is up to the consumer — whether in conjunction with their doctor or not — to decide if a product should be added or sustained in their daily routine.
SCOBY health effects on pregnancy:
Despite its flat, smooth, floating cellulose appearance similar to a mushroom, the SCOBY is actually from an unrelated group of fungi (Jayabalan et al., 2014). While cited as safe for human and animal consumption, the microbial makeup of scobys tend to vary in the bacterial and yeast strains present (Jayabalan et. al., 2014). One study by Murugesan et al. (2005) actually introduced the SCOBY biomass as part of broiler chicks’ diets, and found that the tea fungus contains “179.38 g crude protein, 120 g crude fiber, 4.82 g phosphorus, 6.56 g calcium, and 8.92 MJ metabolizable energy per kilogram of biomass”. That is one nutrient dense biomass! Due to its nutritional content and supposed healing The problem of safe exposure and/or consumption, however, does also lie in the health of the SCOBY. While uncommon under normal fermenting conditions, there is a potential for mold growth on the SCOBY surface that would contaminate both the SCOBY and kombucha batch, making them unsafe for consumption. Dr. Jackson Kung’u (n.d.) from the Mold and Bacteria Consulting Laboratories mentions some of the adverse pregnancy and fetal health effects of mold toxin (mycotoxin) exposure and The problem of safe exposure and/or consumption, however, does also lie in the health of the SCOBY. While uncommon under normal fermenting conditions, there is a potential for mold growth on the SCOBY surface that would contaminate both the SCOBY and kombucha batch, making them unsafe for consumption. Dr. Jackson Kung’u (n.d.) from the Mold and Bacteria Consulting Laboratories mentions some of the adverse pregnancy and fetal health effects of mold toxin (mycotoxin) exposure and consumption. This evidence supports a link between mycotoxin exposure during pregnancy to complications like fetal malformation, pregnancy loss, or stillbirth (Kung’u, n.d.).
The problem of safe exposure and/or consumption, however, does also lie in the health of the SCOBY. While uncommon under normal fermenting conditions, there is a potential for mold growth on the SCOBY surface that would contaminate both the SCOBY and kombucha batch, making them unsafe for consumption. Dr. Jackson Kung’u (n.d.) from the Mold and Bacteria Consulting Laboratories mentions some of the adverse pregnancy and fetal health effects of mold toxin (mycotoxin) exposure and consumption. This evidence supports a link between mycotoxin exposure during pregnancy to complications like fetal malformation, pregnancy loss, or stillbirth (Kung’u, n.d.).
Probiotic health effects on pregnancy:
Probiotics are often the selling point of kombucha due to the general belief that they promote and sustain a healthy microbiome. Lactobacillus, a specific probiotic strain present in most kombucha drinks, is highly revered in probiotic selection for its high tolerance to stomach acid and bile, antimicrobial activity, and antibiotic resistance (Fijan, 2014). Several studies have been conducted on probiotic supplementation during pregnancy looking for any negative health outcome for mother or child. One study found that administering the Lactobacillus rhamnosus strain to mothers during pregnancy resulted in lower scores of postpartum anxiety and depression than their cohorts who received a placebo (Slykerman et al., 2017). Another study looked at infant’s development of atopic eczema among mothers who received probiotic supplementation during pregnancy. They found that infants’ whose mothers were provided probiotic supplementation had a reduced risk of developing atopic eczema, and probiotic use was associated with “enhancing the immunoprotective potential of breast milk” (Rautava et al., 2002). Though the evidence does not conclusively confirm the safety of drinking kombucha while pregnant, it suggests that the probiotic element present in the fermented tea is considerably safe, if not beneficial, to pregnant women and infants — unless one is especially immunocompromised.
Low-level alcohol health effects on pregnancy:
Most commercially sold fermented teas contain alcohol and acetic acid levels lower than 1%, but with longer fermentation can range up to 3% (Nummer, 2013). Effects of alcohol consumption on a fetus have been reviewed and reported, but low-levels or trace amounts of alcohol exposure during pregnancy have confounding results. One study found that the data on low-to-moderate drinking — less than 32 g per week — was inconclusive in making any recommendations (Mamluk et al., 2016). They found that the women who either abstained from drinking or drank less than 32 g per week had no identifiable differences in risk of preterm delivery or low birth weight, whereas women who drank more than 32 g per week had much more elevated risks (Mamluk et al., 2016). This evidence argues that consuming alcohol at such low levels does not, in fact, increase an expecting mother’s risk for preterm birth or low infant birth weight compared to women who did not have any alcohol exposure. While this seems comforting, another study claims that even at low doses, alcohol exposure negatively affects a child’s mental development and behavior later in life (Sood et al., 2001). They also found that the behavioral effects were pronounced even in mothers who consumed as little as one drink per week (Sood et al., 2001). With this countered evidence, the only thing safe to say is that health effects of low-level alcohol exposure — as low as 1% — during pregnancy are nuanced and not fully understood.
Kombucha: What’s the verdict?
Unfortunately, the jury is still out on whether or not kombucha exposure is safe during pregnancy. The efficiency of the maternal-fetal barrier would need to be assessed further before making any definitive conclusions about its safety. However, the evidence cited suggests that drinking kombucha as an immunocompromised individual may have negative health outcomes, or even prove fatal. For a fetus or infant who is considered fairly immunocompromised, direct consumption — without the placental or breastfeeding barrier — would not be advised. Until more studies are done on the topic, the best practice would be to consult with your doctor before consuming kombucha during your pregnancy. To completely avoid exposure, simply forgo the fermented beverage during your pregnancy and while breastfeeding.
References:
Baschali, A., Tsakalidou, E., Kyriacou, A., Karavasiloglou, N., & Matalas, A. (2017). Traditional low-alcoholic and non-alcoholic fermented beverages consumed in European countries: a neglected food group. Nutrition Research Reviews, 30(1), 1–24. doi:10.1017/S0954422416000202
Centers for Disease Control and Prevention. (1996). CDC editorial note. Journal of the American Medical Association, 275(2), 97–98.
Fijan, S. (2014). Microorganisms with claimed probiotic properties: An overview of recent literature. International Journal of Environmental Research and Public Health, 11(5), 4745–67. Retrieved from http://ezproxy.lib.utexas.edu/login?url=https://search-proquest-com.ezproxy.lib.utexas.edu/docview/1525757727?accountid=7118
Jayabalan, R., Malbaša, R. V., Lončar, E. S., Vitas, J. S. and Sathishkumar, M. (2014). A Review on Kombucha Tea — Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus. Comprehensive Reviews in Food Science and Food Safety, 13(4), 538–550. doi:10.1111/1541–4337.12073
Kole, A. S., Jones, H. D., Christensen, R., & Gladstein, J. (2009). A case of Kombucha tea toxicity. Journal of Intensive Care Medicine, 24(3), 205–207. doi: 10.1177/0885066609332963
Koster, J. A. (2015). Permaculture and Kombucha: The Ethics of Scoby. Permaculture Research Institute. Retrieved from https://permaculturenews.org/2015/09/02/permaculture-and-kombucha-the-ethics-of-scoby/
Kung’u, J. (n.d.). Can Black Mold (Stachybotrys chartarum) Affect Pregnancy? Mold & Bacteria Consulting Laboratories. Retrieved from https://www.moldbacteria.com/mold/can-stachybotrys-chartarum-black-mold-affect-pregnancy.html
Lobo, R. O., Dias, F. O., & Shenoy, C. K. (2017). Kombucha for healthy living: Evaluation of antioxidant potential and bioactive compounds. International Food Research Journal, 24(2), 541–546. Retrieved from
http://ezproxy.lib.utexas.edu/login?url=https://search-proquest-com.ezproxy.lib.utexas.edu/docview/1914809022?accountid=7118
Mamluk, L., Edwards, H. B., Savović, J., Leach, V., Jones, T., Moore, T. H. M., . . . Zuccolo, L. (2016). Effects of low alcohol consumption on pregnancy and childhood outcomes: A systematic review and meta-analysis. The Lancet, 388. doi:10.1016/S0140–6736(16)32250–4
Murugesan G. S., Sathishkumar M., Swaminathan K. (2005). Supplementation of waste tea fungal biomass as a dietary ingredient for broiler chicks. Bioresource Technology, 96(16), 1743–8. doi:10.1016/j.biortech.2005.01.006
Nummer, B. A. (2013). Kombucha brewing under the food and drug administration model food code: Risk analysis and processing guidance. Journal of Environmental Health, 76(4), 8–11. Retrieved from http://ezproxy.lib.utexas.edu/login?url=https://search-proquest-com.ezproxy.lib.utexas.edu/docview/1449819709?accountid=7118
Rautava, S., Kalliomäki, M., Isolauri, E. (2002). Probiotics during pregnancy and breast-feeding might confer immunomodulatory protection against atopic disease in the infant. Journal of Allergy and Clinical Immunology, 109(1), 119–121. doi: 10.1067/mai.2002.120273
Slykerman, R. F., Hood, F., Wickens, K., Thompson, J., Barthow, C. . . .Mitchell, E. (2017). Effect of Lactobacillus rhamnosus HN001 in Pregnancy on Postpartum Symptoms of Depression and Anxiety: A Randomised Double-blind Placebo-controlled Trial. EBioMedicine, 24, 159–165. doi: 10.1016/j.ebiom.2017.09.013
Sood, B., Delaney-Black, V., Covington, C., Nordstrom-Klee, B., Ager, J., Templin, T. . . .Sokol, R. J. (2001). Prenatal Alcohol Exposure and Childhood Behavior at Age 6 to 7 Years: I. Dose-Response Effect. Pediatrics, 108(2). doi: 10.1542/peds.108.2.e34
