Mitochondria are one of the types of organelles (cell equivalent to organs) found within our cells. They’re often referred to as the “Powerhouse of the Cell” because of their role in metabolizing food into usable energy. But they may also play a role in aging.
There has to be considerable amount of communication between the nucleus (which controls the cell and houses your DNA) and the mitochondria. Over time, this communication can break down, and this may be what leads to aging (or at least an element of aging).
It makes a certain sense that mitochondria would be important- energy generation is an essential function. Diseases of the mitochondria are severe. But- watch the whole thing:
Trego's Mountain Ear 