Across fertility forums green tea has been popularized as a way to increase cervical mucous, as well as a coffee substitute, due to its lower caffeine content. Research has shown too much green tea may be bad for your baby’s neural tube development in the first month of pregnancy. There are many studies that show green tea to be effective for a variety of health issues, but the research sends a clear message; too much green tea should be avoided while trying to conceive, and during the first trimester of pregnancy.
A study published in 2008 showed that green tea consumption lowers the body’s ability to absorb folic acid. This is very important information for women who are trying to conceive or are pregnant in their first trimester. Folic acid is important for the proper development of the neural tube, which has been shown to help prevent spina bifida.
The study showed that both green and black tea inhibited folic acid (folate) absorption in the intestines.
The open-labeled randomized cross-over study, was to test the interaction between tea and folic acid (0.4mg and 5mg). Healthy human volunteers were used in the trial. Subjects ingested 0.4mg folic acid tablets with water, green or black tea (0.3g extract/250ml) or 5mg folic acid tablets with water or green tea (0.3g extract/250mg). The subjects blood was then tested over an 8 hour period. Serum folate analysis was carried out.
Results showed that 0.4mg folic acid dose, green and black tea reduced the mean Cmax (peak serum concentration) of serum folate by 39.2% and 38.6%, and the mean AUC0 —> ∞ (mean concentration levels of a therapeutic agent in the body) by 26.6% and 17.9%. The 5mg folic acid dose results showed the mean Cmax of serum folate was reduced by 27.4% and the mean AUC0 —> ∞ was decreased significantly by 39.9% by the co-application of green tea. The results suggest an in vivo interaction between tea and folic acid, even low concentrations of green and black tea extracts, which yielded decreased bioavailabilities of folic acid.
Folic Acid is Important for Embryonic Neural Tube Development
As the embryo develops, the neural tube is what becomes the central nervous system, comprised of the brain and the spinal cord. Spina bifida is a disorder in which the neural tube is not closed completely, resulting in a protrusion and/or exposure of the spinal column on the back of the baby. There are different degrees of severity of spina bifida malformations.
Different parts of neural tube close on the 23rd and 27th day gestation, in the first trimester of pregnancy. There is no one single cause of spina bifida, but it has been found that by getting at least 800mcg of folic acid a day may greatly prevent spina bifida.
1-2 in 1000 pregnancies worldwide result in spina bifida. Folic acid supplementation lowers the risk of spina bifida or other neurual tube defects, including the severity of neurual tube defects by 70%.
How Green Tea May Affect Folic Acid Absorption
Another study published in the March 2005 Cancer Research, showed that ECGC, catechin (a natural antioxidant) present in green tea, has higher amounts of ECGC (Epigallocatechin-3-Gallate; antioxidant) than black tea, about 5 times higher. ECGC inhibits the enzyme dihydrofolate reductase (DHFR), which cancer cells need to be able to grow. ECGC is the target of anti-cancer drugs. The researchers found that the green tea catechin is similar to the anti-cancer medication methotrexate. Methotrexate works by preventing cancers cells from making DNA by inhibiting the DHFR enzyme. The ECGC kills cancer cells in the same way as the methotrexate. The main difference is the strength in which ECGC binds to cells compared to methotrexate. ECGC binds weakly to healthy non-cancerous cells, so those cells are not affected like healthy cells exposed to methrotrexate.
ECGC’s binding to DHFR might explain why women who drink large amounts of green tea while trying to conceive and into early pregnancy, may have an increased risk of having a child with spina bifida, or other neural tube disorders. As discussed previously, Folic acid aids in normal development of the embryonic neural tube and protects against spina bifida. It does this by enabling the production of the enzyme DHFR. Doctors agree that a cup or two of green tea a day is not likely to be a problem, consuming large amounts of green tea could decrease the activity of DHFR, increasing risk of neural tube defects.
Ways to Ensure You are Getting Enough Folic Acid in Your Diet
Whole food should be the number one choice for getting enough folic acid!
- Sunflower seeds
- Garbanzo beans
- bell peppers
- collard greens
- romaine lettuce
If you are a woman who consumes more than 1-2 cups of green tea, it may be a good idea to cut back or cut it out completely while trying to conceive. Be sure you are taking a whole food multivitamin and consuming a wide variety of foods that supply adequate amounts of folic acid in your diet.
1. Influence of green and black tea on folic acid pharmacokinetics in healthy volunteers: potential risk of diminished folic acid bioavailability; N. Ceren Alemdaroglu1, Ulrich Dietz2, Siegfried Wolffram3, Hildegard Spahn-Langguth4, Peter Langguth1; Biopharmaceutics & Drug Disposition; Volume 29, Issue 6, pages 335–348, September 2008