What is autophagy?

Is it good to go without eating from time to time? We know that to stay healthy, the body must constantly receive the nutrients it needs. But recent science says that occasionally not eating is also good. It allows various bodily problems to resolve themselves — the human body is even protected from life-threatening diseases like cancer. To understand how this works, you need to know about the process called autophagy, or self-consumption. The word autophagy comes from the Greek words 'auto' and 'phagy' — the first meaning self, and the second meaning eating.

Autophagy is a bodily process by which cells use their own waste to produce energy. It also helps rid the body of damaged and dying cells. In simple terms, when the body faces a shortage of food or nutrition, or needs to survive in an adverse environment, the body's cells use their own waste to generate energy, and at the same time kill off dying and damaged cells to build new ones in their place. The autophagy process occurs when food intake is periodically withheld — as happens during fasting. At that time, due to a lack of nutrition, cells use their own internal waste, which cleans out the inside of the cell. Dying cells are also killed off, and new cells are formed in their place. In this way, the body's cells gain new life.

Autophagy continuously creates new cells in the human body through the destruction of inactive ones. Scientists first noticed this phenomenon in 1960. At that time, they observed how a cell forms a membrane inside itself to trap garbage or damaged material, then moves it into a recycling chamber called the lysosome. But the central mystery was how this organelle breaks down proteins and other substances to regenerate energy. It was Yoshinori Ohsumi who revealed exactly that. The Japanese scientist Ohsumi was the first to discover how this process works inside a cell. In the 1990s, working with yeast, he identified the gene that plays the key role behind autophagy. Although he discovered the autophagy gene in yeast cells, the same mechanism works in higher organisms, including humans. This process operates not only in humans but also in plants and insects. This discovery earned him the Nobel Prize in Medicine in 2016. He currently works as a professor at the Tokyo Institute of Technology.

The autophagy process operates through the breakdown of protein and the formation of new cells in place of damaged ones. This is a natural process of the body. When a cell moves toward dying, the autophagy process accelerates and its scope widens. In this process, the cell uses the waste left inside it to generate the energy needed to carry out repairs. Here, the decay and reuse of these cellular components is much like the cell eating itself. Although this may seem abnormal at first glance, it is actually a natural process in living organisms and also a natural protective mechanism through which the body deals with hunger, bacteria, and viruses. Various malfunctions in autophagy are believed to cause diseases like diabetes and Parkinson's in the body. This process is so important that its failure is even thought to be a cause of age-related diseases like dementia.

Autophagy and cell death:

In certain situations, autophagy is also used to kill cells. This is called programmed cell death, or PCD. This form of cell death is called autophagic cell death. The targeted cells that are killed are referred to as undergoing apoptosis.

In fact, as soon as a cell dies, a new cell is needed there. So along with the loss of a cell, the formation of a new one must also be carried out smoothly. Autophagy maintains the balance between these two tasks — on one hand, unnecessary and damaged cells are destroyed, and on the other, the formation of new cells continues.

Autophagy and stress:

Autophagy helps cells survive in conditions caused by nutritional deficiency or an adverse external environment.

The autophagy process increases when an organism is in adverse conditions, such as during a prolonged period without food. At such times, due to a lack of nutrition, cells generate energy using their internal waste material or disease-causing bacteria. They also kill off damaged and dying cells to complete the formation of new ones — this is how cells gain new life. This process begins in exactly those cells where cellular stress starts. Cellular stress refers to a state where, due to a lack of nutrition, cell growth halts and vitality begins to run out. On one hand, cells are destroyed; on the other, the formation of new cells begins. In this situation, autophagy continues to maintain balance between the two.

Alongside keeping the body healthy, this process also protects organisms from premature aging. Autophagy is at its highest during fasting — that is, when you go without eating for a long, continuous stretch (usually a large part of the day). Scientists hope that, since problems with autophagy cause diseases like diabetes, Parkinson's, and even cancer, this discovery could be used to develop treatments for diabetes, genetic disorders, and many other hard-to-cure diseases.

Source: Google, Kalerkantho, News Medical.