COVID-19 and per capitagreen tea consumption: update

Abstract

Purpose: In spite of the development of numerous vaccines for the prevention of COVID-19 and approvement of several drugs for its treatment, there is still a great need in effective and inexpensive therapy of this disease. Pharmacological evidence suggesting the therapeutic potential of green tea catechins in amelioration/treatment of COVID19 is growing rapidly, however, there are only a few epidemiological studies addressing this possibility. The aim of this study was to provide update regarding ecological study assessing this issue as of January 2021. Methods: The methodological approach used in this report is similar to that described previously. Briefly, information about COVID-19 morbidity (defined as a total number of cases per million population) and mortality (defined as a total number of deaths per million population) for a specific date was directly obtained from Worldometers info. Coronavirus. Analysis was restricted to 134 countries or territories with at least 3 million population. Twenty-one of these countries/territories, with estimated per/capita green tea consumption above 150 g (annually), were considered as a group with the high consumption. Countries/territories with the estimated per/capita green tea consumption below 150 g (N=82) were considered as the group with low the consumption. Results: Pronounced differences in COVID-19 morbidity and mortality between groups of countries with high and low green tea consumption were found as of February 20, 2022. These differences were still observed in a subset of countries with HDI above 0.55. Moreover, in this restricted subset of countries, weak but statistically significant correlations between COVID-19 morbidity (or mortality) and per/capita green tea consumption were observed in a multiple regression model accounting for: population density, percentage of population aged above 65, and percentage of urban population. Conclusion: The obtained results provide additional, though indirect, support of the idea that green tea catechins can be useful for treatment/amelioration of COVID-19. These results are in line with emerging evidence from other studies, including pharmacological. Nevertheless, further research is necessary to directly validate or reject this idea.

Green Tea Consumption and the COVID-19 Omicron Pandemic Era: Pharmacology and Epidemiology

“…Pronounced differences in COVID-19 morbidity and mortality between groups of countries/territories with higher and lower green tea consumption were found as of 6 December 2022 ( Table S3 ). These results extend previous observations, reflecting the epidemiological situation in January 2021 [ 29 ] and before (September and November 2020) [ 20 , 21 , 29 ]. This consistency over a prolonged period may be an additional though indirect argument supporting the therapeutic potential of green tea catechins in the amelioration or treatment of COVID-19.…”

“…Although ecological studies, taken alone, could not confirm a causal relation, these studies are still considered as useful and widely used in the field [ 27 , 30 ]. Limitations and potential concerns relevant to our current ecological results have been discussed in more detail previously [ 21 , 29 ], and briefly outlined below. Indeed, there are many factors that can differentially affect COVID-19 morbidity and mortality in distinct countries (e.g., the percentage of older population; administrative strategies to prevent transmission; condition-specific mortality risks; HDI).…”

“…The information on ‘Worldometer’ is based on official daily reports and considered as a reliable source [ 27 , 28 ]. The methodological approach used in this report is similar to that described previously [ 21 , 29 ]. Nevertheless, some description of this approach is provided below with more details, and specific details of the current work are provided in Supplementary Materials .…”

“…Twenty-one of these countries/territories, with estimated per capita green tea consumption above 150 g annually, were considered as a group with high consumption. Countries/territories with estimated per capita green tea consumption below 150 g were considered as a group with low consumption (see [ 21 , 29 ]. for details).…”