What is the Definition of Autophagy?

Intermittent fasting is known for its many health benefits including weight loss, glucose regulation, lower blood pressure, and more.

Another reason fasting is beneficial is because it stimulates autophagy. But what is the definition of autophagy?

What Is Autophagy?

“Auto” means self and “phagy” means eat. So, the actual definition of autophagy is “self-eating.” This may sound like a weird and undesirable process, but autophagy is actually beneficial!

Our body naturally has trillions of cells and autophagy is a process we evolved to have so that our bodies can ensure our cells are working correctly. During this process, our bodies will get rid of abnormal, old, or malfunctioning parts of cells and then “recycle” the functional parts of them to create new cells (1).

Think of autophagy as a kitchen renovation. You break it down, recycle some of the parts, get rid of items that aren’t working, and then you have a brand-new kitchen that works better!

This process helps ensure that your body’s systems are running smoothly and helps improve your overall health by improving brain function, decreasing inflammation, decreasing risk for type 2 diabetes, and decreasing risk for heart disease (2).

But let’s dive into the biology of autophagy.

Types of Autophagy

There are three different types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy.

Let’s define all three.

Macroautophagy

Macroautophagy is the most common type of autophagy that cells rely on the most.

This process takes place in the parts of the cells found in the cytosol also known as cytoplasmic matrix (a fluid found inside the cells) that surrounds your cells organelles (the “organs” of your cells).

During this process, dysfunctional or broken parts of the cell are engulfed by something called an autophagosome. The autophagosome will then bring these damaged parts of the cell to a part of the cell called the lysosome. The lysosome will then destroy the broken parts.

Once destroyed, the broken-down products are put back into the cytosol to be used again (3).

Microautophagy

Microautophagy is similar to macroautophagy in that the lysosome still destroys broken cellular parts. The main difference is that in microautophagy, the lysosome engulfs the broken cellular parts directly.

In other words, there is no autophagosome or other carrier to bring the damaged parts to the lysosome.

After being broken-down, the destroyed products are released into the cytosol to be recycled for other cellular parts (4).

Chaperone-Mediated Autophagy

The last type of autophagy is called chaperone-mediated autophagy.

During this process, a special protein called the hsc70 chaperone will find damaged proteins in the cytosol. Once it does this, it will bind, which is a fancy work for “stick” or “place” certain materials to the broken part to mark it as a target.

Once this happens, the targeted damaged part will be brought to the lysosome to be destroyed.

After they are destroyed, the parts are placed back into the cytosol where they are reused to make other cellular parts (5).

Intermittent Fasting and Autophagy

You are now probably wondering how intermittent fasting causes autophagy and that’s a good question!

During intermittent fasting, you extend the period of time where you are not eating. This means that you are not giving your body nutrients or calories to be used for energy.

When this happens, your body tries to preserve what it has and will stop making new cellular parts and instead, break down and/or recycle old and damaged parts. This means autophagy will begin to take place.

When your body has a constant supply of nutrients, your cells are able to constantly build new parts of the cell and it has no need to recycle.

How Long Do You Need to Fast to Start Autophagy?

Unfortunately, there is no clear answer here.

One reason is because most studies investigating this have been done in animals like mice or rats. This means that the findings may not directly apply to humans.

Another reason is that there are many other things like activity level, overall health status, and more that can influence how quickly autophagy kicks in.

What we do know is that the longer you fast, the more likely there will be significant autophagy. But don’t use that as a reason to start a long-term fast when you aren’t ready.

There is a good chance any form of fasting may initiate autophagy and even if it doesn’t with you because of your unique body, fasting can help with other aspects of your overall health. What’s important is that you find an intermittent fasting schedule that works for you and allows you to look and FEEL your best.

Bottom Line

The definition of autophagy is that it is a normal bodily process that helps your body to get rid of and re-use old and damaged cellular material. This process helps to promote better health while decreasing your risk of certain diseases.

If you want to kick-start processes related to autophagy, intermittent fasting can help you do that!

Interested in learning more about autophagy, read this article here!