An international team of researchers led by Professor Margaret Rayman at the University of Surrey has found a link between the rate of curing COVID-19 and the regional selenier status in food in China.
When their findings were published in the American Journal of Clinical Nutrition, researchers used data (through February 18) to investigate possible links between the levels of selenium in the body and the cure or death rates of people with the COVID-19 virus in China.
Selenium is an essential trace element derived from food (i.e. fish, meat and cereals) and has been shown to affect the severity of a number of viral diseases in animals and humans. For example, selenium status in HIV-infected people has proven to be an important factor in the progression of the virus to AIDs and death from the disease.
It is well known that China has populations with both the lowest and highest selenier status in the world, due to geographical differences in soil. These differences affect how much of the trace element enters the food chain.
Margaret Rayman, professor of nutritional medicine at the University of Surrey, said: “Given the history of viral infections related to selenicures, we wondered whether the occurrence of COVID-19 in China might be related to the belt of selenier deficiency that extends from the northeast to the southwest of the country.”
When examining data from provinces and municipalities with more than 200 cases and cities with more than 40 cases, the researchers found that areas with high selenium levels were more likely to recover from the virus. For example, in the city of Enshi in Hubei province, which has the highest selenium intake in China, the healing rate (percentage of COVID-19 patients declared “cured”) was almost three times higher than the average of all other cities in Hubei province. By contrast, in Heilongjiang province, where selenier intake is among the lowest in the world, the death rate of COVID-19 was almost five times the average of all other provinces outside Hubei.
The researchers also found that the healing rate of COVID-19 in 17 cities outside Hubei was significantly associated with selenier status (measured by the amount of selenion in the hair).
Kate Bennett, a medical statistician at the University of Surrey, said: “There is a significant link between selenium status and the cure rate of COVID-19, but it is important not to overestimate this finding; we were unable to work with data at an individual level and were unable to take into account other possible factors such as age and underlying disease.”
Ramy Saad, a doctor at the Royal Sussex County Hospital in Brighton who is currently completing an MSc degree in nutritional medicine at the Department of Nutritional Sciences in Surrey, said: “The correlation we have established is compelling, especially given previous research on selenium and infectious diseases. Therefore, a careful and thorough assessment of the role that selenials can play in COVID-19 is certainly justified and can help guide ongoing public health decisions”.