Researchers at Baylor College of Medicine have investigated the
effect of infection with COVID-19 on the levels of oxidative stress,
oxidant damage, and glutathione, the most abundant physiological
antioxidant. Compared to healthy age-matched individuals whose samples
were taken before the pandemic started in 2019, patients hospitalized
with COVID-19 had significantly increased levels of oxidative stress and
oxidant damage, and markedly reduced levels of glutathione.
The results, published in the journal Antioxidants,
suggest that supplementation with GlyNAC, a combination of glutathione
precursors previously shown to reduce oxidative stress and oxidant
damage and increase glutathione as well as improve health indicators
such as inflammation, might be beneficial to COVID-19 patients. However,
GlyNAC supplementation has not as yet been studied in association with
“Increased oxidative stress and reduced glutathione levels are
associated with a number of conditions including ageing, diabetes, HIV
infection, neurodegenerative disorders, cardiovascular disorders,
neurometabolic diseases, obesity, and others,” said corresponding author Dr. Rajagopal Sekhar, associate professor of medicine in the section of endocrinology, diabetes, and metabolism
at Baylor. “We suspected that COVID-19 also might be affecting
oxidative stress and glutathione, and in this study we confirmed this in
adults hospitalized with COVID-19. We found that these defects occur in
all adult age groups including young people, and worsen with increasing
Sekhar and his colleagues worked with 60 participants (25 women, 35
men; age range 21 to 85 years old), who had been admitted to the
hospital based on a diagnosis of COVID-19. The team measured the levels
of oxidative stress, oxidant damage, and glutathione in the patients’
blood samples and compared them with those from healthy individuals.
The researchers organized the samples into three different groups,
according to the age of the COVID-19 patients: the 21- to 40-year-old
group, the 41 to 60 and the 61 and above. In earlier work, Sekhar’s
group had shown that in healthy adults, the levels of oxidative stress,
oxidative damage, and glutathione remain stable until people enter their
60s, when oxidative stress and oxidative damage begin to increase and
glutathione to decline. COVID-19 infection changed this pattern.
“We were surprised to see that the COVID-19 patients in the 21 to 40
and the 41 to 60 groups had much less glutathione and more oxidative
stress than the corresponding age groups without COVID-19,” Sekhar said.
“We knew that healthy people without COVID-19 above the age of 60 years
tend to be glutathione-deficient and have elevated oxidative stress.
However, when the 60-plus age group gets COVID-19, their glutathione
levels were much lower and oxidative stress was much higher than those
of a similar age but without COVID-19.”
“This is an important new discovery,” Sekhar said. “The finding that
younger people with COVID-19 also are glutathione-deficient and have
elevated oxidative stress and oxidant damage is really surprising
because we do not normally see these defects in younger age groups.
These defects appear to get progressively worse with increasing age, and
the oldest patients with COVID-19 had higher level of defects in these
outcomes. We propose that these changes might be involved in the
Oxidative stress results from the accumulation of free radicals,
highly reactive molecules that can damage cells, membranes, lipids,
proteins, and DNA. Cells in the body make glutathione to protect
themselves from oxidative stress. When cells fail to neutralize free
radicals, harmful cellular damage can occur and potentially affect many
“Our previous work has shown that increased levels of oxidative stress and reduced glutathione are not only present in older people, but also in people with HIV, a viral infection, and in patients with diabetes.
We also found that supplementing GlyNAC, a combination of glutathione
precursors, improved these defects in all these populations,” Sekhar
In addition, Sekhar’s work revealed that supplementing GlyNAC to
older people and HIV patients reversed other abnormalities including
inflammation, endothelial dysfunction, insulin resistance, and improved
muscle strength, exercise capacity, cognitive decline, gene damage, and
body composition. Some of these defects also have been reported in
patients with COVID-19.
“Based on our earlier findings on the effects of GlyNAC
supplementation in other populations and the current finding that people
hospitalized with COVID-19 had glutathione deficiency and increased
oxidative stress, we considered whether GlyNAC supplementation could
also combat these defects in COVID-19 and potentially be valuable in
helping the body fight this serious infection. The effects of GlyNAC
supplementation in patients with COVID-19 remain to be investigated in
future research studies,” Sekhar said.
Source: News Release
University of Washington School of Medicine/UW Medicine
January 3, 2022