To what extent can diet be helpful to support the immune system in the fight against coronavirus? A new piece is added to the puzzle thanks to the research published in the journal The American Journal of Clinical Nutrition by a team from the University of Surrey in late April (Zhang et al, 2020). In particular, scientists analyzed the role of selenium taken through the diet and the ability to fight the virus.
Selenium is an essential element taken with the diet, possible sources are, for example, seafood, meat, eggs, Brazil nuts and whole grain cereals. The link between a selenium deficiency and an increase in virulence of RNA viruses such as influenza A was already known. Not only that, benefits after taking selenium supplements had been observed in viral infections such as HIV and Hepatitis B. That's why researchers analyzed the role of selenium in regards to the novel coronavirus. For their analysis they made use of the amount of selenium found in the hair that, as shown by previous studies, is directly proportional to the selenium taken with the diet. For each Chinese city with more than 40 cases, the links between the amount of selenium, the cure rate, namely the cases considered cured, and the death rate were studied. What emerged was that in the areas with, on average, higher amounts of selenium intake the cure rate was higher. For example, the city of Enshi in the province of Hubei with its highest selenium intake has a healing rate three times higher than other cities in the same province. While in the areas with lower selenium intake, such as the Chinese province of Heilongjiang, the death rate could even be 5 times higher than in the other provinces.
The same scientists warn against overestimating these data, in fact the research is very limited and requires further investigation, because, for example, it did not take into account previous diseases or the age of people. In any case, for sure, as we have already seen thanks to previous researches, diet plays an essential role for the health of the immune system. For this reason, including selenium-rich foods in your diet is certainly a useful and beneficial choice.
