Tea is appreciated all over the world for its qualities as a mild physical stimulant, and its psychological value as a soothing, relaxing beverage for its aficionados. It looms large in the traditional medicine and folklore of Asia, and modern medicine is beginning to take an interest in its potential healing ability. Unfortunately, for a small number of people tea provokes an allergy or intolerance.
Tea is made by drying and -- in the case of black tea -- fermenting the leaves of a shrub, camellia sinensis, that's native to China. A relative of the flowering garden camellia, tea plants flourish in semitropical and warm temperate regions around the world. Tea leaves contain a large number of complex organic molecules called phytochemicals, which have been the subject of scientific research for their potential health benefits. The tannins that give strong tea its mouth-drying astringency are among those that have attracted attention from researchers. However, they can also cause adverse reactions in come sensitive individuals.
Tea and Allergies
A food allergy occurs when your body mistakes a harmless food item for a dangerous infection. It responds by creating antibodies and histamines to deal with the perceived threat, which in turn provokes allergy symptoms. A sensitivity, or intolerance, produces symptoms without involving the immune system. Food allergies to tea are extremely rare. Tea allergy usually takes the form of respiratory issues or skin problems for people who work in tea packing or processing, who become sensitized to it over an extended period.
The tannins in tea are a group of phenolic compounds, complex organic chemicals. Many of the phenols in tea leaves are oxidized during the curing process, giving black tea its rich flavor and full body. The tannins remain unchanged, making the tea slightly but pleasantly astringent. Black tea contains lots of tannins, especially strong black tea. A small number of people have an intolerance for tannins. If you suspect that you're reacting to the tannins in black tea, consult your physician for testing. You may need to avoid other foods or beverages containing tannins, as well.
If your doctor's testing doesn't reveal a sensitivity to tannins in other foods and beverages, you'll need to seek out other explanations. Begin by trying another brand of tea, to rule out any potential triggers related to the first company's production process. Buying tea grown in a different region can also rule out environmental factors, such as a spray used in one growing region. If you consistently react to black tea, try drinking oolong. It's only partially fermented, so it contains fewer of the compounds formed by fermentation and oxidation. You also might be able to drink green or white tea.
- University of Kentucky Cooperative Extension Service; Kentucky Kitchens: Tea Time; Janet Tietyen, Ph.D., R.D.
- "European Journal of Clinical Nutrition"; Black Tea -- Helpful or Harmful? A Review of the Evidence; E.J. Gardner, et al.; June 2007
- MedLine Plus: Black Tea
- AllAllergy: Tea
- Palomar Community College; Major Types Of Chemical Compounds In Plants & Animals Part II; Wayne Armstrong
- USDA Agricultural Research Service; Brewing Up the Latest Tea Research; Rosalie Marion Bliss; September 2003
- Chinese-American Tea Association: Guest Research Library