Green Tea Lowers Flu Risk: Early Clinical Evidence

One early trial using green tea against the flu involved gargling three times daily with a weak solution of green tea (50 mg of catechins per cup, of which 60% was EGCG). The theory was that since the throat was a major infection site of influenza, gargling could stop the flu virus there. The theory was right: 1.3% of garglers contracted the flu vs. 10% of the control group. In another more sophisticated trial on 97 healthy adults, a proprietary blend of theanine and green tea polyphenols (apparently worth about 10 cups of green tea per day, but exact amounts were not disclosed) was used for three months during flu season. This trial was randomized, double-blind and placebo controlled. The supplement takers experienced 32% less illnesses and 35% fewer "symptom days." However, participants were included in the statistical analysis even if their compliance (actually taking the green tea pills) was only 70%.