Green Tea for Flu Prevention – Is it an Effective Solution?

By Mike Barrett
Updated October 21, 2023

This article has been reviewed for factual accuracy on October 21, 2023.

green tea leaves

Green tea, a popular beverage consumed worldwide, has long been associated with numerous health benefits. Could protection from the flu be one of them?

Green Tea Catechins and Influenza Prevention

A review and meta-analysis published in the National Center for Biotechnology Information (NCBI) delves into the potential of green tea catechins in preventing influenza virus infection.

The study, titled “Anti-Influenza with Green Tea Catechins: A Systematic Review and Meta-Analysis,” aimed to consolidate existing research on the topic of green tea and flu to provide a comprehensive understanding of green tea’s role in influenza prevention.

Key Findings

  • The review acknowledges the controversial nature of the topic. While several studies have reported the potential benefits of green tea catechins in preventing influenza, the evidence remains inconclusive.
  • The meta-analysis involved a rigorous examination of various studies, considering factors such as the type of green tea catechins, the dosage, and the duration of consumption.
  • The results indicate a potential protective effect of green tea catechins against influenza. However, the extent of this protection and its comparison to other preventive measures, such as vaccines, was not explicitly addressed.

Here is the conclusion:

“Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.”

The findings suggest that green tea catechins might play a role in influenza prevention, though the researchers do call for more rigorous and comprehensive research to validate the findings.

Green Tea Consumption May Prevent Influenza in Children, Study Suggests

Japanese kid and green tea

Another study, this one conducted in Hangzhou, China, has also shed light on the potential benefits of green tea consumption in preventing influenza. This one focused more on the flu affecting elementary school children.

Here are the key findings and insights from the study:

  • Did it work?: The study found a significant inverse relationship between the consumption of 1–5 cups of green tea almost daily and the incidence of influenza infection in schoolchildren.
  • Mechanism Behind the Benefits: Previous research has highlighted the antiviral effects of green tea catechins and the immune-boosting properties of theanine. Experimental studies have shown that tea catechins can inhibit the influenza virus by binding to its molecules and preventing it from attaching to cells.
  • Unexpected Findings: The study also found that general preventive measures like influenza vaccination and hand hygiene were not associated with a reduced incidence of influenza, which was unexpected.
  • Safety Concerns: While green tea is globally recognized as a healthy beverage, the study raised concerns about the potential adverse effects of excessive green tea consumption. High levels of green tea consumption have been linked to liver damage in some cases. Additionally, caffeine, a component of green tea, can have toxic effects in children when consumed in large amounts.
  • Regional Specificity: The study was conducted in one of Japan’s highest tea-producing regions, where both adults and children have a habit of drinking green tea after meals. The daily green tea consumption levels of the children in the study were comparable to average Japanese adults.
  • Limitations: The study had several limitations, including potential biases, the specific geographical setting, and the inability to account for all confounding factors.

The study suggests that consuming 1–5 cups of green tea daily might offer protection against influenza infection in elementary schoolchildren and provides a promising avenue for further research into the potential health benefits of green tea, especially in the context of influenza prevention.