Japanese University Confirms Tea Kills COVID19

On November 27, 2020, Nara Medical University (奈良県立医科大学) reported initial research findings that green tea sold on the Japanese market could reduce COVID-19 virus infectivity in laboratory conditions. After mixing the virus with green tea for one minute, the virus's infectivity dropped by 99%. The research was led by Dr. Hisakazu Yano (矢野寿一). Importantly, this is first-stage laboratory research — the findings have not yet been tested on human consumption of tea against the virus.

The research team tested 10 types of bottled tea — both green tea and black tea — and found that loose-leaf black tea was the most effective at reducing the virus's infectivity. After one minute of contact, the virus's infectious capacity dropped to 1/100 of original levels. After 10 minutes, it dropped to 1/1000. Results varied between different brands of tea, which is why the university was considering publicizing the specific brand names involved after contacting the tea manufacturers.

Dr. Yano's working hypothesis is that catechins (the antioxidant compounds found in tea) attach themselves to the protruding spike proteins on viruses, reducing the virus's ability to infect cells. This mechanism has already been demonstrated in human studies on influenza — consuming tea has been shown to reduce influenza infectivity through catechin action. The team is studying whether the same mechanism applies to COVID-19. The hypothesis is biologically plausible but not yet confirmed in clinical trials.

No — this research is a first-stage laboratory study, not a clinical recommendation. The findings show that tea can reduce virus infectivity in a test tube, but they do not demonstrate that drinking tea protects humans from COVID-19. Vaccines, masks, and standard public health measures remain the established protective tools against the disease. The tea research is scientifically interesting and worth monitoring, but it should not be interpreted as a substitute for established preventive measures or medical advice.

Research on tea and influenza is more developed than on COVID-19. Studies have shown that the catechins in tea — particularly EGCG — can reduce influenza virus infectivity in humans when consumed regularly. The proposed mechanism involves catechins binding to viral surface proteins, similar to the hypothesis being tested for COVID-19. This established research is part of why the Nara team and other researchers think the same approach may apply to coronaviruses, though direct confirmation requires further study.