It is not proved that wine or tannins are beneficial to prevent covid-19

You have sent us a message through our WhatsApp number (+34 666 908 353) in which it is ensured that tannins, a compound of wine, are beneficial to prevent covid-19. Moreover, the message cites one of the researchers of the study who, while waiting for the right drugs to be developed, supposedly recommends taking products with tannins, such as wine, bananas or tea. This is MISLEADING. The research exists and was published in December 2020, but their conclusions are valid only in the in vitro experiments and so far there is no evidence that they can be extrapolated to a real scenario.

“The tannic acid, which is found in grapes and wine, inhibits two key enzymes of coronavirus. On contact, the latter can no longer penetrate human cells […] The researcher […] recommends citizens to consume feed and drinks rich in tannins to reinforce their immunity. This is the case of grapes, wine, bananas, tea and vegetables”

The research in question was published last December in the journal American Center of Cancer Research and Mien-Chie Hung (cited in the viral message) is, effectively, one of its authors. The scientists explain how they observed in vitro that tannic acid, a chemical compound found in grapes and other fruits that is said to have antioxidant and astringent properties, interacted with two proteases (an enzyme that breaks protein bonds) of SARS-CoV-2, inhibiting their activity and preventing "virus entry into cells". The study, however, was carried out at the molecular level and in the laboratory, and the results cannot yet be extrapolated to a real-life scenario. That is, drinking wine has not been proven to help prevent coronavirus disease.

Despite this, wine websites and some mainstream media have interpreted the results as indicating that this trial supports the hypothesis of a protective effect of wine compounds against covid-19 and that the same researcher Mien-Chie Hung "recommends citizens to consume foods and beverages rich in tannins to boost their immunity", such as "grapes, wine, bananas, tea and vegetables". The study does not say this, which has not yet been proven.

The study, in fact, does not encourage anyone to consume products rich in tannic acid or tannins. What it points out is a possible long-term research line studying whether the usage of tannic acid to develop anti-COVID-19 therapies is feasible, due to its promising “capacity to inhibit enzymes essential for the SARS-CoV-2 infection”.

Wine is always not recommended

It is quite common to see studies in the media in which a previously unknown property of an alcoholic beverage, such as wine, is supposedly discovered. Health authorities advise against its consumption, because the few benefits it may have are outweighed by the prejudices. The World Health Organisation (WHO) published a document advising against drinking wine or any other alcoholic drink as a covid-19 treatment: "Alcohol has both short- and long-term effects on almost every organ in your body. Overall, the evidence suggests that there is no safe limit and, in fact, the risk of damage to your health increases with each alcoholic drink you have," they indicate.