Free radicals are molecules that are produced naturally as byproducts of cellular processes, like cell metabolism, but are unstable because they have unpaired electrons on their outside. They are normally neutralized, or made harmless, by antioxidants. However, when there is an imbalance in free radicals and antioxidants, the free radicals can cause damage. This condition is called oxidative stress.

Oxidative stress can be found in both ME/CFS and Long COVID, and it may contribute to other characteristics of the diseases like mitochondrial dysfunction and inflammation. Dr. Ron Davis, the Director of OMF’s Collaborative Center at Stanford University, and other members of OMF’s Scientific Advisory Board released a preprint on oxidative stress in ME/CFS and Long COVID. In their study, they found elevated levels of oxidative stress compared to healthy controls and connections to cognitive problems and the immune system. Read more in the preprint.