Viruses differ from bacteria as they require living hosts to survive and multiply, while bacteria are microorgansisms capable of surviving in a wide variety of environments. The most common viral infections include chickenpox, influenza and the common cold; however, viruses are responsible for more serious conditions such as HIV/AIDS. MedlinePlus reports viruses are difficult to treat, as medications are typically unable to reach the virus. The active compounds within black tea may be able to help treat certain viral infections; however, always discuss the use of black tea with your doctor if you're taking medications or undergoing treatment.
Black Tea Active Constituents
Black tea is the term used to describe tea leaves that have undergone full oxidation, and feature a wilted, rolled or bruised appearance. While black tea is derived from the same plant as green and white tea, the concentration of several active constituents in black tea are weakened due to the oxidation process. The most potent compounds within black tea include polyphenols, alkaloids, tannins, carbohydrates, proteins, chlorophyll and various trace elements. Polyphenols are believed by researchers to be the primary constituents responsible for black tea's health benefits. While some of the polyphenols in black tea are weakened due to the oxidation process, the prolonged oxidation enhances the theaflavin and thearubigin polyphenol concentrations.
Black Tea Effectiveness
Researchers believe that antiviral activity within black tea can be attributed to polyphenolic compounds, which act as antioxidants within the body. The USDA National Agricultural Library cites a study published in the "Molecular Nutrition & Food Research" journal where researchers at the USDA Western Regional Research Center found polyphenol compounds in black tea inhibited viral binding and promoted cell self-defense mechanisms. Initial studies found black tea, as well as green tea, may be able to possibly protect the body from viruses such as influenza, herpes simplex virus, epstein-barr virus and HIV-1. While these studies are promising, further research is required to determine the true effectiveness of black tea as an antiviral agent.
Dosage Recommendations
MedlinePlus suggests consuming anywhere from one to four cups of freshly brewed black tea per day. Discuss the ideal dosage of black tea with your physician, as this beverage contains anywhere from 40 to 120 mg of caffeine per 8 oz. Thus, if you're sensitive to caffeine you may require lower doses.
Safety Considerations
Black tea is considered safe for most; however, consuming more than five cups of tea per day may cause adverse side effects. These side effects may include nervousness, vomiting, headache, diarrhea, mental confusion, dizziness, irregular heartbeat and irritability. Pregnant and breastfeeding women should not consume more than two cups of black tea per day. Those with certain medical conditions, such as anxiety, glaucoma, diabetes, heart problems and high blood pressure, and those taking certain medications should discuss the use of black tea with their physician, as this beverage has the potential to aggravate symptoms or dilute medication effectiveness.
References
- MedlinePlus; Viral Infections; July 2011
- Mayo Clinic; What's the Difference Between a Bacterial Infection and a Viral Infection; James M. Steckelberg, M.D.; October 2009
- National Cancer Institute; Tea and Cancer Prevention: Strengths and Limits of the Evidence; November 2010
- "Molecular Nutrition and Food Research" Journal; Overview of Antibacterial, Antitoxin, Antiviral, and Antifungal Activities of Tea Flavonoids and Teas; October 2006
- MedlinePlus; Black Tea; June 2011
