Expert: Dr. Kristina Conner - 7/28/2006

Question
I've heard that drinking green tea can hamper the absorption of folic acid and iron. Pregnant women are advised not to drink green tea because of the risk of birth defects (i.e. spina bifida). I am NOT pregnant and am not concerned about that particular aspect at this time. However, I am concerned how drinking green tea can affect my health in terms of folic acid and iron. I do know that green tea does have many health benefits. What I'd like to know is its effect on iron and folic acid. I realize that drinking 1 or maybe 2 cups per day of green tea would be okay (I'm guessing). But how many cups a day of green tea is too much? Also, what are the pros/cons of decaf and regular green tea? Another question - I know that folic acid is needed in the development of a fetus. However, what about a normal, fully grown person? What is the benefit of folic acid then? Thank you so much, in advance, for your help! I want to drink green tea because of its antioxidant power (for stress), so I need to know this! Thanks again!  

Answer
Bonnie,
Green tea can decrease the absorption of iron, folic acid, and other nutrients, due to the tannins in them (also with black tea).  It's often recommended that people do not drink much tea during meals, for that reason.  1-2 cups of green tea daily is probably not enough to significantly impair absorption, but to be safe, you could just drink it between meals.  During pregnancy, the need for folic acid is increased in the 1st trimester, but again, 1-2 cups probably wouldn't decrease absorption, especially if drunk between meals, and folic acid levels should be ok if the diet is rich in folic acid with supplemental folic acid.  The caffeine is not desirable during pregnancy, but it is much less than coffee or soda, so it's a better option than those.  Green tea is safe even in high doses unless people are sensitive to caffeine, but a typical amount is 1-3 cups a day (even 3 cups a day is less caffeine than 1/2 cup coffee).  I wouldn't suggest decaf teas, because the processing may be detrimental.  But you can decrease the caffeine by reusing the tea leaves, which lowers the caffeine but increases the antioxidant content with each successive steeping.  
In adults, low levels of folic acid have been associated with increased risk of heart disease.  So, it's important for everyone to get enough folic acid.  Foods are a good way to ensure high folic acid status, and are highly nutritious foods as well.  This includes dark leafy greens, nuts, beans, whole grains.  For women, when pregnancy does happen, folic acid is needed so early in  fetal development, but many women don't know they're pregnant until after this crucial phase.  That's why it's highly recommended to take a folic acid supplement or multivitamin for all women who may become pregnant.  
Thanks for your questions.  
In health,
Dr Conner