Experimental studies have shown that green tea components and theanine prevent influenza infection, while clinical evidence remains inconclusive. Researchers at the University of Shizoka in Japan undertook a study to ascertain if green tea catechins and theanine could prevent the flu and human spirit.
Led byKeiji Matsumoto, PhD, of the Department of drug evaluation and informatics, the researchers conducted a double-blind, randomized, placebo-controlled trial of 200 health care workers for five months from November 2009 through April 2010 in three health care facilities for senior citizens. The group that received green tea and the inane capsules and the control group received a placebo.
The primary outcome was the incidence of clinically defined flu infection. Secondary outcomes were laboratory-confirmed influenza measured viral antigen and the time for which the patient was free from defined influence and affection, meaning the period between the start of the intervention. In the first diagnosis of influenza infection, based on clinically defined influenza infection.
The researchers reported that eligible health care workers were enrolled in randomly assigned to an intervention; 98 were placed in the experimental group receiving the green tea and the inane and 99 were in the placebo group.
The rate of clinically defined influenza was significantly lower in the group receiving the supplements. Only four participants developed the flu, 4.1%, compare with 13 participants in the placebo group, 13.1%. The incidence of influenza infection that was confirmed by laboratory tests was lower in the green tea group. One participant in that group, compared to five in the placebo group were diagnostically confirmed, but this difference was not considered to be statistically significant.
The time from which the patient was free from clinically defined influenza infection was significantly different between the two groups.
The researchers conclude that health care workers for the elderly, benefited from taking green tea catechin and theanine because it may be an effective prophylaxis i.e., it is preventative for influenza infection.
Source: BMC Complementary and Alternative Medicine