What is autophagy?

Autophagy, also known as autophagocytosis; is a process that occurs naturally within the body and is designed to clean out damaged cells. It is an evolutionary self-preservation mechanism that enables the body to eliminate damaged, dysfunctional cells and then recycle useful parts for cellular repair and cleanup. It is a complete, orderly cycle of cellular degradation and renewal that also ensures the removal of debris and the optimal functioning of renewed cells.

The term autophagocytosis is derived from the Ancient Greek words autóphagos, which means “self-devouring”, and kýtos, which means “hollow.”

If you’re interested in autophagy and how you can use fasting to induce it, there’s other crucial information you need to be aware of. Here, we discuss autophagy extensively, including its benefits and potential, as well as its relationship to fasting.

Effects of autophagy on health

Originally, autophagy was considered a primordial degradation pathway designed to protect the body against starvation.

However, further studies reveal that autophagy not only ensures survival during times of want but also plays a critical role in maintaining homeostasis in non-starved cells. It is an adaptive response to different stressors, such as oxidative stress, infectious agents and toxins that accumulate in the cells.

Research shows that autophagy plays a crucial role in maintaining liver health and preventing the development of certain liver conditions. These include Wilson’s disease, nonalcoholic fatty liver disease and alcohol- and drug-induced liver injury.

Since autophagy is intended to be a beneficial process for the body, any defects or problems with it could be potentially deleterious to health. In fact, defects in autophagy have been linked to certain medical conditions, such as neurodegenerative diseases (e.g. Alzheimer’s disease and Parkinson’s disease), metabolic disorders and cancer.

For example, one recent survey on autophagy research found that autophagy performs a dual role in cancer development. Autophagy can help arrest the development of cancer cells but could also promote tumor growth depending on what stage it is in. Moreover, genetic or inborn errors in autophagy are also known to lead to autoinflammatory and neuroinflammatory diseases.

Today, interest in autophagy continues to grow as modulating it offers the potential of treating these diseases. With the anti-aging benefits of autophagy, scientists continue to study the possibility of using it as a therapeutic pathway for the prevention and treatment of age-related medical conditions like cancer and cardiovascular disease.

How autophagy works at a molecular level

Autophagy and fasting

It is widely accepted that starvation triggers autophagy in the body. But can fasting lead to the same biological response?

Dietary manipulation through intermittent fasting has been studied for its potential to suppress tumor growth and for cancer treatment. The effect of ketosis has also been studied in relation to autophagy in brain cells. Short-term fasting has also been linked to neuronal or brain cell autophagy. Moreover, both fasting and calorie restriction have been found to induce autophagy in different tissues and organs.

Fasting or going without food for several hours or even days can trigger autophagy as it puts the cells under stress, so they respond to it the way they would to starvation. By limiting the frequency of your food intake, your cells will get fewer calories than they normally need to function the way they usually do.

When food is limited, the cells are forced to make more efficient use of their own resources. The stress of fasting would then induce autophagy, causing the cells to seek out damaged and dysfunctional cells, clean them out and recycle usable parts. However, most research on autophagy involves the use of animals such as lab mice and monkeys, so scientists are still unsure about which specific cells are triggered in humans in response to fasting.

That being said, the benefits of fasting, particularly in relation to autophagy are worth pursuing. But how do you achieve a state of autophagy through fasting?

Considerations when fasting to induce autophagy

While waiting for the results of an ongoing exploratory clinical study on the effects of fasting on autophagy in humans, it is widely accepted that it takes around 12 to 16 hours of continuous fasting to activate autophagy.

However, it may require two to four days of fasting for humans to experience significant autophagy. This means that in order to achieve maximum autophagy benefits, you need to deprive yourself of food for longer. Results can also vary based on each person’s metabolism.

Autophagy is believed to be induced by considerable reductions in the level of glucose and insulin in the body. In animal studies, autophagy has been observed after 24 hours of fasting, which then peaked at around 48 hours.

It must be noted, however, that to date, there are no conclusive studies on humans that provide information on the optimal period of fasting designed to achieve autophagy. Moreover, attempting to induce autophagy every day may not be beneficial to one’s metabolism.

Therefore, you should always discuss your attempts to fast for the purpose of triggering autophagy with your doctor or healthcare provider.