Certain people, such as healthcare workers, the young and the elderly, and people with chronic health conditions such as diabetes or lung disease, are at greater risk of getting the flu than others. This study looked at the effect of green tea extracts in helping prevent flu in Japanese healthcare professionals who care for the elderly.
In this study, 200 healthcare workers were randomly assigned to receive capsules of a green tea extract that contained compounds known as catechins (378 mg per day) and theanine (210 mg per day) or placebo for five months. The majority of participants had also been vaccinated against the flu.
Results showed that the incidence of influenza in the green tea group was significantly lower compared with the placebo group (4 versus 13 people were diagnosed with the flu).
Prior studies have also shown that green tea may help prevent influenza, and the authors of this study comment, “The consumption of tea extracts including catechins and theanine has also been reported to enhance systemic immunity and prevent the occurrence of upper respiratory tract infection and influenza symptoms in healthy adults.” Larger research trials are needed to confirm these study findings.
The influenza virus is a cause of serious illness and even death, so it is important to take preventive measures to stay well:
(BMC Complement Altern Med 2011:11:15)