Autophagy allows your body to break down and reuse old cell parts so your cells can operate more efficiently. It’s a natural cleaning out process that begins when your cells are stressed or deprived of nutrients. Researchers are studying autophagy’s role in potentially preventing and fighting disease.

What is autophagy?

Autophagy (pronounced “ah-TAH-fah-gee”) is your body’s process of reusing old and damaged cell parts. Cells are the basic building blocks of every tissue and organ in your body. Each cell contains multiple parts that keep it functioning. Over time, these parts can become defective or stop working. They become litter, or junk, inside an otherwise healthy cell.

Autophagy is your body’s cellular recycling system. It allows a cell to disassemble its junk parts and repurpose the salvageable bits and pieces into new, usable cell parts. A cell can discard the parts it doesn’t need.

Autophagy is also quality control for your cells. Too many junk components in a cell take up space and can slow or prevent a cell from functioning correctly. Autophagy remakes the clutter into the selected cell components you need, optimizing your cells’ performance.


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Why is autophagy important?

Autophagy is essential for a cell to survive and function. Autophagy:

  • Recycles damaged cell parts into fully functioning cell parts.
  • Gets rid of nonfunctional cell parts that take up space and slow performance.
  • Destroys pathogens in a cell that can damage it, like viruses and bacteria.

Autophagy plays an important role when it comes to aging and longevity, too. As a person ages, autophagy decreases, which can lead to a build-up of cellular junk parts and, in turn, cells that aren’t functioning at their best.

What happens during autophagy?

Autophagy-related proteins (ATGs) make autophagy possible. ATGs cause structures called autophagosomes to form. Autophagosomes carry the junk cell pieces to a part of the cell called a lysosome. A lysosome’s job is to digest or break down other cell parts.

Imagine lysosomes — part of a cell — eating other parts of the cell. The word “autophagy” is a combination of two Greek words translated to mean “self-devouring”:

  • “Autos” means self.
  • “Phagomai” means to eat.

Lysosomes eat the junk cell parts and then release the reusable bits and pieces. The cells use these raw materials to make new parts.


What causes autophagy?

Autophagy occurs when your body’s cells are deprived of nutrients or oxygen or if they’re damaged in some way.

Think of it this way: Autophagy is a recycling process that makes the most of a cell’s already-existing energy resources. The process ramps up when your body has to make the most of these resources because your cells aren’t getting them from an outside source.

With autophagy, a cell essentially eats itself to survive. The bonus is that this survival process can lead to cells that work more efficiently.

Can you induce autophagy?

You can induce autophagy by stressing your cells to send them into survival mode. You can induce autophagy through:

  • Fasting: Fasting means that you stop eating for a certain amount of time. Fasting deprives your body of nutrients, forcing it to repurpose cell components to function.
  • Calorie restriction: Restricting your calories means decreasing the number of energy units, or calories, your body consumes. Instead of depriving your body of calories completely (as with fasting), you limit them. This forces your cells into autophagy to compensate for the lost nutrients.
  • Switching to a high-fat, low-carb diet: This type of diet, commonly referred to as a keto diet, changes the way your body burns energy, so that instead of burning carbs or sugar for energy, it burns fat instead. This switch can trigger autophagy.
  • Exercise: Exercise stimulates processes that increase the activity of ATGs, such as stressing your skeletal muscles. Exercise can induce autophagy, depending on the type of exercise you’re doing and its intensity.

Still, being able to induce autophagy doesn’t mean you should. For instance, fasting, calorie restriction or switching to a keto diet may not be safe if you’re pregnant, breastfeeding or if you have a condition like diabetes. Similarly, you shouldn’t begin a vigorous exercise routine without consulting a healthcare provider.


How long do you have to fast for autophagy to occur?

Studies involving animals suggest that autophagy may begin between 24 to 48 hours of fasting. Not enough research has been collected on the ideal timing to trigger human autophagy.

Talk to a healthcare provider if you’re considering significant changes to your diet, like fasting. While fasting may be a good option for some people, it may put others’ health at risk. Don’t risk it.

What is the relationship between autophagy and disease?

Scientists once thought of autophagy as housekeeping — your cells’ way of tidying up to survive and function correctly. Within the past 20 years, scientists have discovered that autophagy may also play an important role in preventing and responding to disease.

For instance, studies have shown that problems with autophagy may be associated with:

Problems with autophagy are also associated with cancer. “Junk” accumulating in a cell may increase the risk of errors in a cell’s genetic material or DNA. Genetic mutations, or changes, in cell DNA can lead to cancer cells forming.

Still, autophagy isn’t a clear-cut harmful or beneficial process concerning disease prevention or treatment. For instance, some studies have shown that autophagy may prevent tumors from forming in the early stages of cancer. Other research has shown that autophagy may encourage tumor growth by helping cancer cells function more efficiently.

Also, most studies about the relationship between autophagy and disease haven’t been performed on humans. Most testing has studied animals, like mice or rats, who (like all mammals) experience autophagy.

As scientists collect more evidence about the relationship between autophagy and disease, we’ll get a clearer idea of how this process may play a role in certain conditions and long-term health.

A note from Cleveland Clinic

Recent conversations about autophagy often frame it as a health trend — a process to get younger, healthier cells. In reality, autophagy isn’t that simple. Autophagy is indeed essential for healthy cells. It’s also true that problems with autophagy are associated with some diseases. Still, there’s not enough research to support inducing autophagy as a wellness strategy. Depending on your health, fasting, reducing your calories, making drastic changes to your diet or taking on a rigorous exercise routine may be dangerous. Speak to a healthcare provider if you’re curious about making any lifestyle change that can disrupt your body’s natural processes.

Medically Reviewed

Last reviewed on 08/23/2022.

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