Aging is characterized by rising levels of oxidative stress, the presence of oxidative molecules and the damage they cause to molecular machinery in cells, and rising levels of chronic inflammation, an inappropriate and harmful overactivation of the immune system. It is noted that these two aspects of aging and age-related disease appear to go hand in hand, when one is elevated, so is the other. Why is this the case?
The obvious place to start any such investigation is the mitochondrion. Every cell is populated by hundreds of mitochondria, responsible for packaging chemical energy store molecules in a process that produces reactive oxygen species (ROS) as a byproduct. While the cell uses ROS production as a signaling mechanism under normal circumstances, dysfunctional mitochondria produce too great a flux of ROS. Equally, mitochondria are also involved in many other vital cellular processes. For example, there are well-mapped pathways of protein interactions that lead directly from mitochondrial activity to the activation of inflammatory signaling on the part of their host cell.
This is the explanation for the observation that inflammatory disease is accompanied by oxidative