Fasting has amazing benefits, and the best is a dramatic increase in autophagy and apoptosis followed by a massive boost in stem cell production. Autophagy is a genetic program that is very important: it clears away damaged cells to use for energy, while apoptosis is a genetic program that causes damaged cells to self-destruct.
Both of these processes prevent damaged cells from becoming cancer cells. When we clear away damaged cells this also means those cells are less likely to become senescent, which is what can happen when too much damage accumulates. A senescent cell is technically a living cell but it is not functioning in a way that is consistent with maintaining the overall health of an organ, in fact, quite the opposite. Senescent cells can accelerate the aging of nearby cells and promote tumor growth by secreting pro-inflammatory molecules and other factors.
Senescent cells are bad news and as we age they are everywhere from our livers to our hearts to our brains and they accelerate the aging process. It has been shown that mice, when given a compound that increases the clearance of senescent cells, it actually extends their average lifespan by 20 percent! Another way that fasting really shines particularly prolonged fasting is that prolonged fasting has a very robust effect on increasing stem cell numbers.
The regenerative power of tissues and organs declines with age. It is the stem cells that provide this regenerative power and because stem cell numbers decline with age so does organ function which means anything that can counter that is a win!
Fasting also causes cells to clear away damaged mitochondria and recycles their defective components for energy, called mitophagy followed by a concomitant generation of new mitochondria (called mitochondrial biogenesis). This is really a great thing because mitochondria accumulate damage with age (just as cells do) and this can accelerate the aging process.
So not only does fasting clear away old, damaged mitochondria, it also generates new young healthy mitochondria to replace the damaged ones. There has been some evidence suggesting a low-carb, high fat diet may modestly increase mitochondrial biogenesis but not mitophagy. Another thing fasting does is it increases the levels of something called nicotinamide adenine dinucleotide (or NAD+ which I will just refer to as NAD). NAD levels always increase during a fasted state and decrease during the fed state (no matter what food type). NAD is a very important cofactor for many metabolic enzymes, which just means you need it for these enzymes to work properly.
Your mitochondria need NAD to produce energy from glucose or fatty acids. Any time there is chronic inflammation or DNA damage occurring, this sucks up the NAD and so the mitochondria suffer. Also, NAD levels decrease in multiple tissues with aging. There are several different compounds which are various forms of vitamin B3 that dramatically increase NAD levels and have been shown to delay aging in multiple tissues in mice.
Fasting activates many repair processes including repair of damaged DNA, damaged cells, damaged mitochondria, and damaged proteins.
You must be in a fasted state to repair damage which is why most repair processes occur during sleep because that is when most people are in a fasted state. Fasting improves blood sugar, insulin sensitivity, and blood lipids and improves inflammatory markers, including C-reactive protein and tumor necrosis factor-alpha (TNF-α), and improves adiponectin, leptin, and brain-derived neurotrophic factor in humans.
With a prolonged fast we see entire organ systems can shrink and then experience renewal during the re-feeding period. So, it should be pretty clear we’re actually talking about a whole different level of cellular clean-up that can occur, which is above and beyond what we get in shorter fasts. There’s still a lot of research going on to better tease out the differences between shorter, let’s say 2 day fasts, and fasts that meet the definition of being a “prolonged fast.”
Did you know that eating right as per your macro intake can either make or break your fasting? Proper nutrition puts your body in a better metabolic position to clean up, restructure and experience the full benefit of the fasting state. Check out My Complete Ramadan programme. This programme offers you full one-on-one consultation to set up a programme that works for you! Click here to get started!
C. A. Lamb, T. Yoshimori, and S. A. Tooze, ‘The Autophagosome: Origins Unknown, Biogenesis Complex’, Nat Rev Mol Cell Biol, 14 (2013), 759-74
R. C. Russell, H. X. Yuan, and K. L. Guan, ‘Autophagy Regulation by Nutrient Signaling’, Cell Res, 24 (2014), 42-57