On a cellular level, aging is related to your mitochondria. Mitochondria are tiny organelles inside your cells that extract energy from the food you digest and create a chemical called adenosine triphosphate, or ATP, which stores energy for cellular function. They’re essentially the power plant of the cell. As you get older, though, your mitochondria begin to falter. This leads to an increase in reactive oxygen species, also known as free radicals. These damage your cells and cause widespread chronic inflammation, laying the groundwork for degenerative diseases like cancer.