Source: TheEpochTimes.com
An animal study published in the journal Brain, Behavior, and Immunity found that a COVID-19 infection may leave behind certain proteins, which can trigger the process that causes cortisol levels to drop. This results in increased inflammation and immune overreaction to stress.
The effect on cortisol may underlie many changes associated with long COVID, which has many neurological and neuropsychological symptoms, such as brain fog, anxiety, sleep disturbances, fatigue, depression, and post-traumatic stress disorder.
“Our study suggests that low cortisol could be playing a key role in driving many of these physiological changes that people are experiencing with long COVID,” lead author Matthew Frank, a senior research associate with the Department of Psychology and Neuroscience at the University of Colorado at Boulder, said in a press release.
The discovery brings science one step closer to understanding long COVID, which affects 10 to 35 percent of people after contracting an infection with the SARS-CoV-2 virus, according to the researchers.
Lingering Proteins Link to Low Cortisol
Researchers in the study noted several earlier experiments that led to their recent investigation. Prior findings included:
- SARS-CoV-2 sheds antigens classified as spike proteins, referred to as S and S1.
- These proteins are immune-stimulating agents that may linger in the plasma and various organs of long COVID patients for an extended time following an infection.
- High plasma levels of S and S1 correlate with neuropsychiatric symptoms.
Based on the above, the researchers theorized that spike proteins may produce physiological effects that prolong the duration or increase the magnitude of the neuroinflammatory response to future stressors. To determine the effect of the proteins on the brain and nervous system, the researchers injected S1 into the spinal fluid of rats.
After seven days, compared to a control group, the rats given S1 showed a 31 percent decrease in corticosterone, a hormone similar to cortisol. The reduction was found in the hippocampus, a brain structure involved in learning, decision-making, and memory. After nine days the corticosterone levels dropped further to 37 percent.
Frank noted that nine days is a long time in the lifespan of rats since they usually live for only two to three years. He added that this drop has important health ramifications because of the multiple actions of cortisol:…