By Lori Wolfe, Certified Genetic Counselor at MotherToBaby North Texas

Did you know that the month of March is green tea month? Green tea has been said to have many health benefits, including: preventing memory loss, promoting bone health, decreasing risk of cancer, increasing dental health, reducing the chance of getting type 2 diabetes, and helping us lose weight. Green tea is loaded with nutrients and antioxidants, and has been said to be “the healthiest beverage on the planet.” So, given all of this wonderful news, who wouldn’t want to join Lucky the Leprechaun in the month of March and enjoy a cup of green tea?

As an information specialist with MotherToBaby, I recently had a pregnant mom named Lynn text me, asking: “Can you drink green tea if you take your prenatal vitamin later? How much does green tea impact folic acid absorption? I am in my first trimester and have had some green tea throughout pregnancy, and I am now worried about it impacting my folic acid absorption.” Wow, I thought, that is a great question! As the MotherToBaby specialist on the other side of the text, I started researching her questions so that I could give her the most up-to-date information out there.

First, let’s talk about folic acid: what is it and why is it important to pregnant women?
We all need folic acid every day in our bodies to help make new cells. Folic acid is a synthetic form of Vitamin B9, also known as folate. It is very important to take enough folic acid just before and during pregnancy. Many studies have shown that taking the recommended daily allowance of 400 micrograms per day during pregnancy reduces the chance that the baby will have serious birth defects of the spine and brain, called neural tube defects (NTD).

So what’s the connection between drinking green tea, folic acid, and pregnancy?
Green tea contains something called catechins, which have been shown to partially prevent the cells in the intestines from absorbing folic acid. Studies have shown that when women are drinking a lot of green tea, they have lower levels of folate in their system. That means there is less folic acid that can cross the placenta and get to the baby, and the baby can thus be at a higher risk for having a NTD. This can occur when a pregnant woman is drinking more than three cups of tea per day. Green tea and some forms of black tea such as Oolong tea can be high in catechins. Taking a daily prenatal vitamin has been shown to reduce this possible risk in heavy tea drinkers.

Another concern with drinking green tea during pregnancy is the caffeine content.
The good news is that green tea contains less caffeine than coffee (about 20 to 50 mg of caffeine per cup in green tea verses an average of 100 mg of caffeine per cup in coffee). Moderate levels of caffeine (about 200 mg/day) have not been shown to increase any risks in pregnancy. See our MotherToBaby fact sheet for more information on caffeine and pregnancy at https://mothertobaby.org/fact-sheets/caffeine-pregnancy/. Women may want to limit their tea consumption during the first trimester when the baby’s neural tube is developing to avoid the chance of decreasing absorption of folic acid. After this point, drinking one cup of green tea per day has not been shown to increase any risks for the baby.

I counseled Lynn that she can enjoy a cup of green tea now and then, as occasionally drinking green or black tea has not been shown to increase the risk for any problems during pregnancy. So, raise that cup of green tea along with Lucky the Leprechaun and enjoy “going green” in the month of March!

If you have questions about exposures during pregnancy or breastfeeding, contact an expert at MotherToBaby. You can reach us by phone at 866-626-6847 or by text at 855-999-3525. You can also email or live chat with us by visiting https://MotherToBaby.org.

Lori Wolfe, CGC, is a board certified Genetic Counselor and the Director of MotherToBaby’s North Texas affiliate. MotherToBaby aims to educate women about medications and more during pregnancy and breastfeeding. Along with answering women’s and health professionals’ questions regarding exposures during pregnancy/breastfeeding via MotherToBaby’s toll-free number, text line and by email, Wolfe also teaches at the University of North Texas, provides educational talks regarding pregnancy health in community clinics and high schools.

About MotherToBaby
MotherToBaby is a service of the Organization of Teratology Information Specialists (OTIS), suggested resources by many agencies including the Centers for Disease Control and Prevention (CDC). If you have questions about exposures during pregnancy and breastfeeding, please call MotherToBaby toll-FREE at 866-626-6847 or try out MotherToBaby’s new text information service by texting questions to (855) 999-3525. You can also visit MotherToBaby.org to browse a library of fact sheets about dozens of viruses, medications, vaccines, alcohol, diseases, or other exposures during pregnancy and breastfeeding or connect with all of our resources by downloading the new MotherToBaby free app, available on Android and iOS markets.

References:
Gunners, Kris, https://www.healthline.com, 1/17/18.

“Folic Acid, Key Points,” www.marchofdimes.org, 2/18.

Rongwei, Ye et al, “Tea Drinking as a Risk Factor for Neural Tube Defects in Northern China, Epidemiology, Volk 22, No 4, July 2011. Yazdy, Mahsa et al,
“Maternal Tea Consumption during Early Pregnancy and the Risk of Spina Bifida”, Birth Defects Research (Part A), Clinical and Molecular Teratology 94:56-76, 2012.

“Why to go Easy on the Green Tea During Pregnancy,” Neifeild, Rachel, RD. CDN, www.babymed.com, 2/23/18.