What is autophagy and can I switch it on myself?

Autophagy is your cells' own clean-up process. Damaged proteins and worn-out cellular components are wrapped in small pouches, broken down, and recycled as building materials. This is no marginal emergency process: it is a continuous quality-control system that keeps your cells running.

The most potent known way to stimulate autophagy is a lack of food. When few nutrients are available, an energy sensor inside the cell activates a trigger molecule that sets autophagy in motion. When nutrition is plentiful, a growth signal does exactly the opposite: it actively blocks that same trigger molecule. Fasting or an extended period without eating therefore acts, biologically speaking, as a direct on-switch for this process.

Physical exercise also activates a switch in the cell nucleus that instructs the cell to increase its clean-up capacity. This has been demonstrated in cell and animal research, but how strong this effect is in humans, and which type or duration of exercise produces it most reliably, has not yet been well mapped out.

Several substances have been linked to autophagy in research, including resveratrol, quercetin, and curcumin. They may work through an enzyme that puts the cell into 'clean-up mode'. However, almost all the supporting evidence comes from cell cultures and animal research, not from large studies in humans. You cannot currently say with certainty that a supplement reproduces these effects in you.

Important: more autophagy is not always better. During a heart attack, autophagy is protective in the oxygen-deprived phase, but in the recovery phase too much of the same process can actually kill cells. The process is tightly regulated and context-dependent. Anyone thinking about influencing autophagy for medical reasons would do well to discuss this with a doctor.