We don’t want our new cars to age. We also want a new appliance we just bought to last forever. But after a few years they both start to get beat up and need maintenance. Perhaps you need to repair them with new parts. Yet after so long new parts are not the solution and you have to get rid of them. In essence they die.
We all want our aging to slow down. Like our cars many people get new body parts; a knee or hip replacement. Some even have heart transplants. The truth is our bodies are in constant repair and maintenance mode. You can’t see it because it’s at the cellular level.
As our cells age they need to be removed and replaced. Eventually a cell gets to old to be repaired and needs to be destroyed to make way for a healthy new cell.
In a process called apoptosis, when a cell reach a certain age its programmed to “commit suicide” according to Dr. Jason Fung. As he states, “While this may sound kind of macabre at first, the process constantly renews cell populations, making it essential for good health. But when just some cellular components need to be replaced, a process called autophagy kicks in.”
What is Autophagy?
The word autophagy was created by Nobel Prize-winning scientist Christian de Duve. It’s taken from the Greek auto (“self”) and phagein (“to eat”). So the word literally means “to eat oneself.” According to Dr. Jason Fung in his book, The Complete Guide to Fasting, “Autophagy is a form of cellular cleansing; it is a regulated, orderly process of breaking down and recycling cellular components when there’s no longer enough energy to sustain them. Once all the diseased or broken-down cellular parts have been cleansed, the body can start the process of renewal. New tissues and cells are built to replace those that were destroyed. In this way, the body renews itself. But it only works if the old parts are discarded first.”
Why is this important for you?
While we focus on new cell growth by putting the proper nutrition in our bodies and exercise and movement, we must not forget that the first step is destroying the old broken-down cellular machinery. Apoptosis and autophagy are both necessary to keep us healthy and running smooth.
When these processes are hijacked, diseases such as cancer occur, and the accumulation of older cellular components may be responsible for many of the effects of aging. Dr. Jason Fung
These unwanted cellular components build up over time if the autophagocytic processes are not routinely activated.
What turns autophagy off?
Dr. Jason Fung says, “Increased levels of glucose, insulin, and proteins all turn off autophagy. And it doesn’t take much. Even as little as 3 grams of the amino acid leucine can stop autophagy.”
The mammalian target of rapamycin (mTOR) pathway is an important sensor of nutrient availability. When we eat carbohydrates or protein, insulin is produced and the increased levels, or even the amino acids from the protein, activate the mTOR pathway. The body senses that there is plenty of energy available and there is no need to eliminate the old subcellular damaged machinery. Then autophagy is suppressed. The constant intake of food such as in the American diet, suppresses autophagy.
On the flip side, when mTOR is silent, or dormant–then it’s not being triggered by increased insulin levels or amino acids for ingested food–autophagy is promoted. In effect, when the body senses the temporary absence of nutrient, it must prioritize which cellular parts to keep. The oldest most worn out cellular parts gets discarded. Then in a most amazing function, these old discarded parts are recycled. The amino acids from these broken-down cell parts, are delivered to the liver and through gluconeogenesis are converted into new proteins and glucose. In other words, the body’s amazing survival of using old parts to restore itself!
What’s the strongest stimulus to autophagy?
The strongest stimulus to autophagy currently known is fasting. Fasting is unique in our culture yet stimulates the process of autophagy better than calorie restriction. Why? Even in calorie restriction diets people eat less but more constantly and insulin levels remain high. By eating constantly from the time we wake up until we go to sleep we prevent autophagy’s cleansing pathway mTOR.
Simply put, fasting cleanses the body of unhealthy or unnecessary cellular debris. Dr. Jason Fung
Fasting also stimulates growth hormone which signals the production of new and better parts! Fasting gives your body a complete renovation, even better than The Property Brothers construct better looking and more valuable older homes on their most watched show on HGTV.
Fasting and exercise triggers both the breakdown of old cellular parts and the creation of new ones, thus both may be considered the most potent anti-aging methods in existence.
Autophagy and Cancer
Cancer it another disease that may be a result of disordered autophagy. Currently science is learning about the role mTOR plays in cancer. To date, mTOR inhibitors have been approved by the FDA for the treatment of various cancers. Fasting also stimulates autophagy. Dr. Thomas Seyfried, a professor of biology at Boston College, have proposed a yearly seven-day water-only fast for this very reason.