The bright side: COVID-19 mortality is low in sunny areas-consumer health news

Friday, April 9, 2021 (HealthDay News)-COVID-19 may have a new enemy, the Sun.

New studies suggest that sunny areas of the United States have lower COVID-19 mortality rates than cloudy areas, and that the sun’s UV rays may provide some form of protection against disease. ..

A Scottish research team led by Richard Weller at St. John’s Land, said the effect was not due to a better intake of vitamin D, a healthy “sunshine vitamin.”

“Effects appear to be independent of the vitamin D pathway,” the researchers reported, stressing that the study was not designed to prove a causal relationship.

However, the study authors concluded that “optimizing exposure to sunlight could be a public health intervention” if sunlight helps prevent severe COVID-19.

The new report was published on April 8th British Journal of Dermatology..

For this study, Weller’s group analyzed all COVID-19 deaths recorded in the US mainland from January to April 2020, and analyzed it for solar radiation in approximately 2,500 US counties over the same period. Compared with (UV) level data.

Studies show that people in areas with the highest levels of UVA exposure (95% of the sun’s UV light) are less likely to die from COVID-19 than people in areas with the lowest levels of UVA exposure. Shown by.

Researchers performed similar analyzes in the United Kingdom and Italy with the same results. Averaged from the results of the three studies, the Scottish team has a probability of death from COVID-19 of about 3 minutes for every 100 kilojoules (standard measurement) increased per square meter of sunlight in a particular area. Said that it decreased by 1.

Researchers sought to explain specific factors associated with the risk of coronavirus infection and death, such as age, ethnicity, wealth, population density, air pollution, temperature, and local infection rates.

The association between increased exposure to sunlight and reduced risk of death from COVID-19 was associated with vitamin D levels, as only areas with UVB levels that were too low to produce significant vitamin D in the body were included. I couldn’t explain it because it was high. Study, the author said.

So how does extra sunlight suppress COVID-19?

According to Weller’s group, one possible reason is that the skin releases a chemical called nitric oxide when exposed to sunlight. Studies in several laboratories have shown that nitric oxide can reduce the ability of new coronaviruses to replicate and spread. The authors of the study plan to follow up on further research on this theory.

A previous study by the same team found that increased exposure to sunlight was associated with improved heart health, lower blood pressure, and reduced heart attack. Since heart disease is a known risk factor for death from COVID-19, they suggested that previous studies may also help explain new findings.

Two COVID-19 experts in the United States agreed that the findings were interesting, but worth further research.

“This study does not establish a cause and effect, but at best shows a relevance,” said Dr. Robert Gratter, an emergency physician at Lenox Hill Hospital in New York City. He was not surprised that vitamin D did not bring any health benefits.

“Although there is evidence that vitamin D may have beneficial effects on immune function, certain antiviral effects have not been proven at this time,” Glatter said. “In fact, randomized controlled trials of people with moderate to severe COVID-19 who received high doses of vitamin D showed no effect.”

Dr. Ameshua Darja, a senior scholar at the Johns Hopkins Health Security Center in Baltimore, is a virus expert. He said the study raises interesting questions, but the nitric oxide hypothesis needs further research.

“If we put the links together to show the mechanism of how this is happening, we hope that this series of studies will proceed to show that there are also vitamin D-independent benefits of sunlight. “Adalja said.

For more information

The US Centers for Disease Control and Prevention COVID-19 prevention..

Source: Johns Hopkins Bloomberg, Baltimore, Maryland Senior Scholar, Health and Security Center, Graduate School of Public Health. Robert Glatter, MD, Emergency Doctor, Lenox Hill Hospital, New York City; British Journal of Dermatology, April 8, 2021; University of Edinburgh, News Release, April 8, 2021