What does autophagy mean?
Autophagy is the biological process by which a cell digests and recycles its own components. Derived from Greek roots meaning 'self-eating,' the term describes how cellular structures called lysosomes break down damaged proteins and worn-out organelles, converting them into raw materials the cell can reuse. Far from being destructive, this internal housekeeping is essential: it helps cells survive starvation, clears out malfunctioning parts, and supports immunity and healthy aging. In its broader original sense, autophagy can also refer to an organism's consumption of its own tissue under extreme conditions such as famine. The word entered mainstream awareness after molecular biologist Yoshinori Ohsumi won the 2016 Nobel Prize in Physiology or Medicine for uncovering the mechanisms of autophagy in yeast, and it has since become common in discussions of fasting and longevity. It remains primarily a scientific term, formal in register.
nounThe process by which a cell breaks down and recycles its own damaged or redundant components through the action of lysosomes. More broadly, it can refer to an organism's consumption of its own tissue.
- (Cell biology) The regulated process by which a cell degrades and recycles its own cytoplasmic components via lysosomes.
- (Broader biology) The consumption of an organism's or cell's own tissues, as in extreme starvation.
"During periods of starvation, cells rely on autophagy to recycle their own components for energy."
"Fasting is thought to trigger autophagy, prompting cells to clear out damaged proteins and organelles."
"In prolonged starvation, the body may resort to autophagy, breaking down its own tissue to sustain vital functions."
The plural is grammatically valid but rarely used; the singular covers most contexts since the process is discussed as a general phenomenon.
"Different stress conditions induce distinct autophagies within the cell."
Your cells literally eat themselves to stay alive — and the scientist who figured out how, Yoshinori Ohsumi, won the 2016 Nobel Prize in Physiology or Medicine for it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of autophagy
Autophagy comes from the ancient Greek roots 'autos' meaning 'self' and 'phagein' meaning 'to eat,' so it literally means 'self-eating.' It was coined in the early 1960s, around when scientists first observed cells engulfing their own contents under the electron microscope. The same Greek elements appear in other English words: 'auto-' in autobiography and autonomy, and '-phagy' in words like sarcophagus, which originally meant flesh-eating.
Related word forms
How autophagy is actually used
A technical term used chiefly in cell biology and biomedical writing; it has gained wider currency in popular health and wellness media discussing fasting. Plural 'autophagies' exists but is rare.
Easily confused with autophagy
Apoptosis is programmed cell death that eliminates the whole cell, whereas autophagy is a recycling process by which a cell digests and reuses parts of itself while typically surviving.