Why regular exercise reduces systemic inflammation and promotes a healthy immune system may soon come into focus—and offer insight into how much and what type of exercise may help.

Numerous studies have shown that exercise can have an anti-inflammatory effect, but pioneering research by Duke University scientists in Chapel Hill, North Carolina, may point to the underlying mechanisms.

According to findings reported in Science Advances (2021; 7 [4], abd9502), muscles that experience exercise appear to have an innate ability to reduce inflammation. Scientists conducted the study with lab-grown engineered human muscle and sought, in particular, to examine the role of a pro-inflammatory molecule, interferon gamma, that has been associated with muscle wasting and dysfunction.

“We know that chronic inflammatory diseases include muscle atrophy, but we wanted to see if the same thing would happen to our engineered human muscles grown in a Petri dish,” said lead study author Zhaowei Chen, PhD, a postdoctoral researcher in biomedical engineering. “Not only did we confirm that interferon gamma primarily works through a specific signaling pathway, we showed that exercising muscle cells can directly counter this pro-inflammatory signaling independent of the presence of other cell types or tissues.”

“When exercising, the muscle cells themselves were directly opposing the pro-inflammatory signal induced by interferon gamma, which we did not expect to happen,” said senior investigator Nenad Bursac, PhD, professor of biomedical engineering at Duke University. He added, “There are notions out there that optimal levels and regimes of exercise could fight chronic inflammation while not overstressing the cells. Maybe with our engineered muscle, we can help find out if such notions are true.”

See also: Inflammation: Obesity, Diabetes, Aging and Exercise