Black tea is made from the fermented leaves of the Camellia sinesis plant, which also yields green, white and oolong teas. As tea leaves ferment, their chemical and pharmaceutical properties change slightly. Black tea has a high concentration of tannins, which are acidic compounds with nutritional and medicinal properties. Served hot or cold, black tea is popular throughout the world. In general, low to moderate amounts of black tea are regraded as safe for pregnant women.
Tannins Explained
Tannins encompass a wide range of compounds found in many foods and beverages. Known for their potent astringency, tannins create a flavor that might be described as bitter, earthy or puckery. Tannins are responsible for bitter flavor of black tea, green tea and coffee. It also occurs in fruit juices and wines; "dry" wines have higher tannin content that affects their flavors. They also occur in most legumes, such as peas and beans, which are considered safe and healthy for pregnant women.
Tannin Safety
Tannins are safe to consume in the amounts commonly found in food. Nova Scotia Environment, or NSE, notes that these compounds even occur naturally in well water. While tannins may cause an unpleasant taste, color or odor, NSE ultimately classifies them as "benign" when they come from natural sources. However, the regular or excessive consumption of tannins in tea may cause some health-related problems. During pregnancy, when maternal health is critical for the well-being of the unborn baby, women are likely to be most concerned about the tannins' effects on the human body.
Pregnancy Risks
When used excessively, black tea can have side effects for both a pregnant women and her unborn child. According to the National Institutes of Health, tannins in tea can worsen iron deficiency anemia. This is of particular concern during pregnancy, when sufficient levels of blood iron are essential for a child's neurological development and for the mother's general well-being. Additionally, caffeine in tea may cause other side effects, including miscarriage and low birth weight. For this reason, the NIH urges expectant mothers to drink no more than two cups of black tea per day.
Other Complications
Tannins in black tea can cause drug interactions, which increase the risk of drug-related side effects for both the mother and child. Black tea tannins can decrease the absorption of tricyclic antidepressants such as amitriptyline and imipramine, which are sometimes used during pregnancy to treat depression and related conditions. Tannins can also reduce the absorption of phenothiazines, a class of drugs used to treat allergies and mental illnesses. If you are pregnant and taking medication, talk to your health-care provider about any foods and drinks that you should avoid.
Member Comments