Scientists say the sleep aid melatonin may bolster people's defenses against the coronavirus by reducing inflammation
- Melatonin, a sleep hormone often synthesized into supplement form, shows potential in combating coronavirus, according to a new study.
- Researchers found that patients who took melatonin were significantly less likely to be diagnosed with COVID-19. This was particularly true for Black patients and those with diabetes.
- Previous evidence suggests melatonin can help with respiratory viruses by reducing inflammation. Clinical trials are underway to test whether it might lead to better coronavirus outcomes.
Melatonin, a hormone that regulates sleep cycles and is popularly used as an over-the-counter sleep aid, could help to make people more resilient to the coronavirus, a new study found.
For the study, published November 6 in PLOS Biology, researchers from Cleveland Clinic analyzed data from 26,779 patients (of which 8,274 tested positive for COVID-19) to try to identify links between easily-accessible medications and coronavirus outcomes.
The team was hoping to find possible candidates for repurposing already-available drugs as treatments to protect people from COVID-19 or lessen the blow of an infection, according to Dr. Feixiong Cheng, lead author of the study and assistant staff in Cleveland Clinic's Genomic Medicine Institute.
They found that people who reported taking small daily doses of melatonin — synthesized in labs and added to pills, powders, and even gummies — were 28% less likely to be diagnosed with COVID-19, the disease caused by the novel coronavirus.
That's promising data that, while lots of efforts are aimed at treating coronavirus patients, melatonin may potentially prevent people from getting sick in the first place by limiting how much the body overreacts to the virus.
"Its protective effects on virus infection is to target the host, not by promoting the host defense system against virus but by increasing the tolerance of the host to the virus," Cheng told Insider. "Increase in the tolerance of the host to the virus will reduce the tissues and organs damage of the host and allow the host to survive sufficiently long to develop adaptive immune response, particularly the specific antibody."
It could help by reducing inflammation
The researchers found no evidence that melatonin made a COVID-19 infection less severe — though that's something they are investigating in a series of clinical trials at the Cleveland Clinic.
Previous research on melatonin suggests it has benefits against other types of respiratory viruses similar to coronavirus by reducing oxidative stress and inflammation, as well as regulating the immune system. The latter could be particularly helpful for COVID-19 patients, since some severe cases of the illness are linked to an overactive immune response.
If melatonin does help to lessen COVID-19's effects, it could be something of a breakthrough, since there are so few available treatments, and melatonin is easy to access and produce, Cheng said.
"Importantly, the cost of melatonin is much lower than other drugs under ongoing COVID-19 trials, which will be great to fight the pandemic by accessibility to the general population."
Melatonin seemed most effective in Black people and people with diabetes
The researchers found doses between 2.5 mg and 10 mg to be optimal.
The most striking difference in outcomes was seen in Black participants of the study. Those that took melatonin were 52% less likely to be diagnosed with COVID-19, according to the study. Among study participants with diabetes, melatonin was linked to a 48% lower change of being diagnosed.
These numbers were small, however. While African Americans comprised about a third of all coronavirus patients, less than 1% of those took melatonin.
"We don't know the exact mechanisms behind why melatonin has more benefits in African American patients or individuals with diabetes," Cheng said. "Based on a previous COVID-19 genetic paper published in BMC Medicine, one possible explanation is the genetic factors may be associated with melatonin responses in different populations."
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