The first study published in Cell & Bioscience last November found that drinking approximately one to two cups of coffee daily is enough to inhibit COVID-19 infections caused by different strains of SARS-CoV-2. In particular, it found that the consumption of coffee addressed infections caused by the original SARS-CoV-2 strain and its subsequent variants – the B117 alpha strain, the B16172 delta strain and the B11529 omicron strain.
The study authors from Taiwan examined coffee’s ability to fight off COVID-19 infection by purchasing three kinds of coffee – ground, instant and decaffeinated – from supermarkets. They discovered that all the coffee types they scrutinized possess the ability to inhibit viral infection in cells.
The study authors also found that adding milk or sugar does not impact coffee’s antiviral properties. Even decaffeinated coffee still has the capability to interrupt SARS-CoV-2 infection, which is important to know for caffeine-sensitive populations. Moreover, they mentioned in their paper that the optimal timeline for coffee to inhibit SARS-CoV-2 infection is within six hours after drinking.
According to the researchers, there are two ways coffee protects human cells against SARS-CoV-2 infection. First, compounds in coffee inhibit the spike protein’s ability to bind with human angiotensin-converting enzyme 2 (ACE2) in human cells. Second, they reduce the activity of transmembrane serine protease 2 (TMPRSS2) and cathepsin L (CTSL).
Taken together, drinking one to two cups of coffee as well as decaffeinated coffee daily can potentially reduce SARS-CoV-2 infection – including wild-type, alpha, delta and omicron variants, the researchers concluded. Another study by the same research team from Taiwan focused on the ability of Coffea arabica leaves to address SARS-CoV-2 infection. Their earlier study published in July 2022 in the International Journal of Biological Sciences found that C. arabica leaves can inhibit the entry of the pathogen behind COVID-19 and its various strains into human cells. This is because C. arabica leaf extracts have several phytochemicals that are also present in coffee beans, including chlorogenic acid, caffeine, quinic acid and mangiferin, which inhibit infection by preventing the viral spike protein from binding with ACE2 receptors in human cells and reducing the activity of TMPRSS2.
