"It’s long been known that cells accumulate flotsam from the wear and tear of everyday living. Broken or misshapen proteins, shreds of cellular membranes, invasive viruses or bacteria, and worn-out, broken-down cellular components, like aged mitochondria, the tiny organelles within cells that produce energy, form a kind of trash heap inside the cell.
In most instances, cells diligently sweep away this debris. They even recycle it for fuel. Through a process with the expressive name of autophagy, or 'self-eating,' cells create specialized membranes that engulf junk in the cell’s cytoplasm and carry it to a part of the cell known as the lysosome, where the trash is broken apart and then burned by the cell for energy.
Without this efficient system, cells could become choked with trash and malfunction or die. In recent years, some scientists have begun to suspect that faulty autophagy mechanisms contribute to the development of a range of diseases, including diabetes, muscular dystrophy, Alzheimer’s and cancer. The slowing of autophagy as we reach middle age is also believed to play a role in aging."