Objectives: Several lines of emerging pharmacological and epidemiological evidence imply that overall risks related to COVID-19 may be reduced by green tea catechins. Therefore, it may be expected that: (i) higher green tea consumption is associated with lower COVID-19 morbidity and/or mortality; (ii) countries with higher per/capita green tea consumption would be less affected by COVID-19. The aim of this study was to assess the second possibility.
Study design: This was a cross-sectional study.
Methods: Among countries with at least 3 million population (n=134), countries with relatively high (above 150 g) per/capita green tea consumption have been tentatively identified (n=21); (ii) normalized to population values of COVID-19 cases (morbidity) and deaths (mortality) for groups of countries with high and low per/capita green tea consumption were compared.
Results: Striking differences in COVID-19 morbidity (and mortality) between groups of countries with higher and lower green tea consumption. The differences were still observed after the adjustment for the onset of the disease. Besides, preliminary analysis using multiple linear regression approach suggests that the associations are present at the level of individual countries.
Conclusion: Evidence supporting the idea that green tea constituents could reduce overall risks related to COVID-19 has been obtained. The results are promising and are in line with emerging evidence from other studies including pharmacological ones. Nevertheless, because of limitations of this study the idea still should be considered as a hypothesis requiring further assessment.
Green tea consumption and cognitive function: a cross-sectional study from the Tsurugaya Project
