Autophagy is a natural recycling and detox process that occurs in our cells that comes from the Greek words for "self" (auto) and "eating" (phagy). Intermittent Fasting, by its nature, creates a state of energy deprivation. When the body senses that it's running low on external sources of energy (like food), it turns inward for fuel. This is where autophagy kicks in. In the absence of a constant supply of nutrients, cells initiate autophagy to recycle internal components and maintain essential functions. Essentially, fasting puts cells in survival mode, triggering this self-cleansing process.
What Does Autophagy Do?
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Recycling Process
Autophagy is not just about waste removal; it's a sophisticated recycling system. This cleanup process includes cellular recycling of our damaged cells into functioning components. The body naturally identifies what could be reused and repurposed into new cellular structures. These broken-down components are repurposed to build new cell parts, making it essential for cellular maintenance, repair, and survival.
Autophagosomes engulf and sequester these marked cellular materials, and fuse with lysosomes, which contain powerful enzymes that break down the enclosed contents into their basic building blocks.
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Junk Removal
During autophagy, older and weaker cells begin to break down while damaged or dysfunctional proteins and organelles are removed. This process functions as a highly efficient garbage disposal mechanism, selectively targeting and eliminating cellular waste, damaged organelles, and toxic protein aggregates that can accumulate over time.
As cellular structures degrade and autophagy begins, autophagosomes form and fuse with lysosomes to begin the degradation of cellular waste. Nonfunctional cells that have become damaged or are performing poorly are culled and removed. The body's natural turnover of cellular structures uses autophagy to eliminate toxins, pathogens, and dying cells to regenerate newer, healthier cells.
Autophagy + Fat Metabolism
Autophagy supports the selective degradation of fat stores as important mechanism for regulating lipid metabolism. The metabolism of fat is essential for maintaining energy balance, and disruptions in autophagy can impact fat metabolism, potentially contributing to metabolic disorders and obesity.
Lipophagy
Lipophagy is a specialized form of autophagy that focuses on the breakdown and degradation of lipid droplets within cells. Lipophagy helps release fatty acids from the lipid droplets, making them available as a source of fuel for various tissues and organs.
Science Behind The Function:
Lipophagy involves the formation of autophagosomes that envelop lipid droplets, which are subsequently delivered to lysosomes for degradation. During fasting or periods of calorie restriction, the body faces a reduced influx of nutrients, including dietary fats. In response to this nutrient scarcity, the hormone glucagon becomes elevated, while insulin levels decrease. This hormonal shift signals the body to shift its energy source from glucose to stored fat.
How It Applies To Fasting:
Lipophagy is essential for mobilizing stored fat reserves and plays a crucial role in energy homeostasis, making it an integral part of how the body responds to fasting and periods of calorie restriction. Intermittent fasting may stimulate lipophagy as a means of mobilizing stored fat for energy during fasting periods, helping with weight loss and lipid metabolism.
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Natural Renewal
A Body Cleansing Mechanism
Autophagy enables the removal + recycling of damaged or cellular components as part of the body's natural renewal process
Autophagy + Cellular Recycling
Understanding the different forms of autophagy is crucial, not just for scientific research but also for potential therapeutic applications. These mechanisms are involved in numerous physiological processes, including aging, immune response, and the body’s ability to combat various diseases. Enhancing or regulating these autophagic processes could lead to breakthroughs in treating conditions like cancer, neurodegenerative diseases, and metabolic syndromes.
Macro-Autophagy
Macroautophagy, often referred to simply as autophagy, is a cellular process crucial for maintaining cellular health and homeostasis. This type of autophagy is often simply referred to as "autophagy" and is crucial for responding to starvation and stress conditions.
Science Behind The Function:
In this process, cellular debris and dysfunctional organelles are enclosed in a double-membraned vesicle known as an autophagosome. These vesicles envelop and sequester damaged organelles, protein aggregates, and other cellular components. The autophagosomes fuse with lysosomes, an organelle filled with enzymes, leading to the degradation and recycling of the contents providing the cell with essential building blocks.
How It Applies To Fasting:
During fasting, autophagy is upregulated as a survival mechanism. When the body is in a state of nutrient deprivation, it enters a mode that promotes the breakdown of cellular components to generate energy. When the body is in a state of .deprivation, such as during fasting or caloric restriction, it enters a mode that promotes the breakdown of cellular components to generate energy.
Micro-Autophagy
Microautophagy is a less complex but equally important process. This method is more straightforward and is primarily involved in the routine maintenance of cellular homeostasis, managing the turnover of cellular components.
Science Behind The Function:
Microautophagy directly internalizes cargo through invagination, or "turning inside out", of the lysosomal membrane. Instead of forming an autophagosome, micro-autophagy causes the lysosome itself to engulf small portions of cytoplasm, or even entire organelles, directly through its membrane. This process helps maintain cellular homeostasis by selectively removing specific organelles and proteins as needed.
How It Applies To Fasting:
During fasting or periods of nutrient scarcity, cells increase their reliance on microautophagy to recycle cellular components and conserve energy. This process selectively targets and degrades damaged organelles, protein aggregates, and other cellular components that may be dysfunctional or no longer needed by the cell. This process contributes to the body's adaptive responses to periods of nutrient deprivation and supports overall cellular health and maintenance.
Chaperone-Mediated Autophagy
Chaperone-mediated autophagy (CMA) is unique in its protein quality control functions while being especially important in stress responses and the aging process. This complex, and specific pathway provides a highly selective process to manage what proteins and other components cross the lysosomal barrier.
Science Behind The Function:
Unlike the other forms of autophagy that can engulf a range of cellular debris, CMA specifically targets individual proteins marked for degradation. These proteins contain a recognition motif that is identified by chaperones (specialized proteins). The chaperones then escort these marked proteins to the lysosome for direct translocation across the lysosomal membrane and subsequent breakdown.
How It Applies To Fasting:
Intermittent fasting enhances CMA by increasing the availability of chaperone proteins that facilitate the selective breakdown of damaged proteins. This process maintain protein quality while preventing the accumulation of toxic protein aggregates. By engulfing and degrading these cytoplasmic materials, microautophagy helps ensure that the cell can efficiently recycle essential nutrients and maintain a clean and functional cytoplasmic environment, ultimately contributing to overall cellular well-being.
Mitophagy
Mitophagy is a specialized form of autophagy dedicated to the disposal of mitochondria, the cell's powerhouses. This process is vital for cellular health, as malfunctioning mitochondr ia are linked to a range of diseases, including neurodegenerative disorders and metabolic conditions. When mitochondria become damaged or superfluous, they can be harmful to the cell. Mitophagy selectively identifies and targets these mitochondria for degradation, thereby preventing potential damage from dysfunctional mitochondria.
Science Behind The Function:
During fasting, the combination of AMPK activation and decreased insulin signaling promotes mitophagy, ensuring the efficient removal of impaired mitochondria. AMP-activated protein kinase (AMPK) becomes activated during periods of low energy availability, and in turn activates Unc-51-like autophagy-activating kinase 1 (ULK1), Parkin, and PINK1 proteins. These proteins play a crucial role in tagging damaged mitochondria for removal.
How It Applies To Fasting:
During fasting or periods of nutrient deprivation, the demand for energy production may increase, leading to the need for efficient and functional mitochondria. Mitophagy helps to ensure that only healthy and well-functioning mitochondria are retained, while damaged ones are eliminated. By selectively degrading damaged mitochondria, mitophagy promotes the renewal and maintenance of a high-quality mitochondrial pool, which is essential for optimizing energy production and metabolic health.
Find Out Your Somatotype
Start building your own intermittent fasting plan with this short quiz to determine your somatotype and the type of fast that works best for your body: