Could consuming a cup of coffee be an effective way to protect yourself against infection with coronavirus?
What has not yet been proven in practice is at least very plausible, according to biochemical research.
A team led by chemistry professor Nikolai Kuhnert, including Dorothea Schmidt and Nicholas Ohl of Jacobs University, was able to show experimentally — in the laboratory — that the chemical compound 5-caffeoylquinic acid (or chlorogenic acid), which is found in coffee, inhibits the interaction by a factor of 50 between the SARS CoV-2 spike protein of the corona virus and the ACE-2 receptor, the docking site for the virus on the human cell.
A regular cup of filter coffee — in the laboratory setting, it comprised exactly 200 milliliters — contains about 100 milligrams of the 5-caffeoylquinic acid. Experiments in the laboratory showed that 5-caffeoylquinic acid in this concentration is high enough to prevent the docking of the spike protein to the ACE-2 receptor, and, therefore, also inhibit the infection process. To prove that this process works in practice as well, further research is required.
It also takes further studies to determine how long the inhibitory effect of 5-caffeoylquinic acid would last.
"As chemists, we cannot answer the practical question of whether drinking coffee could really serve as a preventive measure to protect against infection. But we can say it is plausible," said Kuhnert. "Many people drink coffee and that it has many other positive effects is well established," says the chemist. Regular coffee drinkers suffer less frequently from type II diabetes, for example, the scientific evidence for this is very good, he points out.
For their studies on the effect of 5-caffeoylquinic acid on spike protein and ACE-2 receptor, the team had to develop a new measurement technique: differential scanning fluorimetry, or nano-DSF. The team recently published a detailed description of this method in the journal Food & Function, titled: "Investigating the interaction between dietary polyphenols, the SARS CoV-2 spike protein and the ACE-2 receptor."
As a next step, the findings on the interaction between coffee and the coronavirus will now be communicated to researchers in psychology as well as social science.
"Epidemiological studies could determine whether regular coffee drinkers become more often infected with Corona or not," said Kuhnert.