Mitochondrial dysfunction in aging is a signaling crisis, not an energy crisis

Old mitochondria produce less ATP. But cells have excess capacity—drop ATP by 30% and most cells still function fine.

The real problem is signaling. Mitochondria regulate calcium, ROS, and apoptosis. When they dysfunction, they send 'danger' signals that trigger cell cycle arrest and inflammation.

The energy shortfall is a side effect. The signaling corruption drives aging.