The human body contains trillions of cells, each one of them acting like a mini factory where various chemical processes take place. Over time the cell’s components can wear out and production of related waste products can accumulate, leading to the build-up of unwanted molecules, which can damage some of the components of the cell.
Fortunately, the body has a vital process, called autophagy, in which cells can “clean out” any unnecessary or damaged components.
Lately the process of inducing autophagy has become the next trend in overall body health, but a word of caution, it is not as simple as it seems to be as many aspects are still unclear.
What is autophagy?
As cells are the basic building blocks of every organ and tissue in the body, each cell contains multiple parts that keep this mini factory functioning, for example one of the components in the cell is the mitochondria, which act like miniscule power stations that produce energy and are seen as the energy powerhouses of cells. Like a factory, the components in a cell require a great deal of resources to function. When resources are scarce, the internal components are recycled to provide essential building blocks to sustain vital functions. Over time, the multiple parts in the cell can become defective or stop working, ending up as litter inside an otherwise healthy cell.
To the rescue comes autophagy, described by the Cleveland Clinic as the body’s cellular recycling system. The amazing process of autophagy disassemble the litter, while repurposing the salvageable parts into new and usable cell parts. As too many junk parts can take up too much space in the cell and affect its functioning, autophagy helps the cell to discard the parts it doesn’t need. It also converts the clutter into useful cellular components, which optimizes the cell’s performance.
How autophagy works:
The origin of the word autophagy explains, in a nutshell, how it works. It is a combination of two Greek words – autos, meaning self, and phagomai, meaning to eat. Autophagy literally means “self-devouring”.
Autophagy-related proteins in the cell cause structures called autophagosomes to form and engulf the junk cell pieces in bubble-like structures before fusing with the cell’s waste disposal organelles, called lysosomes. Lysosomes are organelles that contain enzymes which can degrade and destroy molecules. The major function of the lysosomes is to “devour” (eat, digest, break down) the junk parts of the cell and then release the reusable bits, which are used as raw materials to make new parts in the cell.
The autophagy recycling process ramps up when cells are deprived of nutrients or oxygen, whenthe cell literally eats itself (using junk parts) to survive. The upside is that this process gets rid ofunwanted molecules and dysfunctional parts, such as misfolded proteins, damaged organelles, and pathogens in the cell, and can result in cells working more efficiently.
Research in the field of autophagy has revealed that autophagy is not a nonselective process for the destruction of unwanted cellular material as previously viewed, but it is now regarded as a fine-tuned mechanism, contributing to cellular homeostasis (maintaining internal stability) through selective degradation and recycling. When cells are starving, they seem to have mechanisms to control what they recycle, says Harvard.
Scientists agree that there is still much to learn about the regulation of the different types of autophagy involved in the different components of a cell. Degradation of the cellular structures through autophagy pathways has individually been named mitophagy (mitochondria), nucleophagy (nucleus), lipophagy (lipid droplets), pexophagy (peroxisomes), ribophagy (ribosomes) and reticulophagy (endoplasmic reticulum).
Mitophagy, for example, is an important quality control mechanism as healthy mitochondrial function is essential for cell survival. Mitophagy mediates the clearance of damaged mitochondria once they have played their part.
Importance of autophagy:
Autophagy is essential for the survival and functioning of cells, as it recycles damaged parts into functioning cell parts, while getting rid of nonfunctional cell parts that slow down the functioning of the cell and take up space. Autophagy also plays a role in destroying pathogens such as viruses and bacteria.
Aging decreases autophagy, which can lead toa build-up of cellular junk parts, leading to cells not functioning at their best.
Over the past 20 years scientists have discovered that autophagy is more than just the cell’s way of tidying up to survive and function properly, as they found that autophagy may also play an important role in responding to and even preventing disease. Several health conditions have been linked to problems with autophagy, such as kidney disease, liver disease, diabetes, heart disease, Parkinson’s disease, and Crohn’s disease. Studies on the effects of autophagy on cancer have indicated that it plays a complex role and may either help to stall the development of cancer, or promote the growth of cancer, depending on the stage of the tumor.
It must be noted that most of the studies on the relationship between autophagy and disease were performed on animals and not humans. More human studies are needed to determine how autophagy can influence the treatment of health conditions, and whether enhancing the process of autophagy could be used as a new treatment for different conditions.
Enhancing autophagy:
Autophagy can be enhanced or induced by various stress conditions for cells, such as exercise or when energy giving fuel is restricted through calorie restriction or fasting, causing the cell to “eat itself”.
- Exercise induces autophagy in muscle tissue, as autophagy markers increase immediately after short bouts of intense exercise or over the course of moderate-intensity training sessions. Exercise intensity was found to be more powerful at inducing autophagy.
- Calorie reduction of 10-40% of overall caloric intake is a potent autophagy inducer. Long-term calorie restriction of more than three years leads to an increased expression of autophagy genes.
- Both extended and intermittent fasting results in an increase in autophagy activity and an increase in the production of the autophagy gene. The current evidence suggests anywhere between 18 hours of fasting to 4 days, will trigger autophagy.
- Switching to a high-fat, low-carb diet changes the way the body burns energy from burning carbs to burning fat instead and can trigger autophagy.
Certain foods containing polyphenols (compounds found in plants) have been linked to enhanced autophagy, such as green tea, grape skin as found in red wine, nuts, berries, apples, onions, curcumin in turmeric, milk thistle, and soybeans.
Conclusion:
The inducing of autophagy has recently been promoted in certain circles as a health trend to get younger, healthier cells in the body. Autophagy activity of the body decreases with aging. In essence autophagy is an ultimate cellular detox! While autophagy is indeed beneficial for healthy cells, scientists do not have a full picture yet of the health implications of autophagy. Active autophagy has been shown to prevent an excessive inflammatory response causing tissue damage. Autophagy has also been shown to play an essential role in the various phases of wound healing.
References:
Autophagy. Published online and reviewed 23 August 2022. Cleveland Clinic. USA. (www.clevelandclinic.org)
Autophagy: Everything you need to know. Published online and reviewed 2 March 2020. Medical News Today. (www.medicalnewstoday.com)
Autophagy: What you should know before starting your fast. Published 10 January 2023. InsideTracker. (www.insidetracker.com)
Self-eating decisions. Published 16 July 2020. Harvard Medical School. (www.harvard.edu)
An overview of autophagy: Morphology, mechanism, and regulation. Published 20 January 2014. Antioxidants & Redox Signaling. (Journal). National Centre for Biotechnology Information. US National Library for Medicine. National Institutes of Health. USA. (www.ncbi.nlm.nih.gov)
7 Herbs that enhance autophagy and cellular healing. Published online. Dr. Jockers. (www.drjockers.com)
Autophagy and mitophagy in cellular damage control. Published 5 February 2013. Redox Biology. PubMed Central. National Centre for Biotechnology Information. US National Library for Medicine. National Institutes of Health. USA. (www.ncbi.nlm.nih.gov)
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