Autophagy - Your Cells' clean up System
Fact Sheet 28 - article from September 2023 newsletter
Marvellous Mitochondria – The Cell’s Energy Supply
In the last newsletter, I mentioned that eons ago mitochondria were bacteria which merged with larger nucleus/DNA containing cells (eukaryotic) to provide energy. Because mitochondria retained their own independent DNA/genes, they could immediately respond to stress, converting food and oxygen to high energy ATP that powers more than 90% of the biochemical reactions in a cell. However, intense mitochondrial activity generates heat with electron sparks (free radicals), impairing their function, and when cell energy falls below 10%, specific molecules initiate recycling, removing damaged mitochondria and initiating production of new mitochondria.
I also mentioned that mitochondria are not just an energy factory but counter adverse environmental conditions with a ‘danger response’ reducing energy and focusing on cellular defence. When we are young, mitochondria are abundant and efficient, but after 40 years most people have significant mitochondrial dysfunction. As mitochondrial suffer wear and tear, they lose efficiency and function, leading to chronic disease, ageing, and cancer; mitochondria are a biological clock of the ageing process.
Magic of Exercise
I also discussed how exercise improves health and wellbeing and mentioned that short bursts of intense exertion, followed by rest, is known to improve lung function, a strong predictor of longevity. Intense mild to moderate forms of aerobic exercise - running, walking, swimming, and cycling – use more oxygen and increase the muscle-cell mitochondria count by as much as 50% in six weeks, even in older people. However, be aware that extreme physical activity can be detrimental by damaging and inflaming the skeletal muscles, heart, and even other internal organs.
House Cleaning
It is a delight when our house is ‘spick and span’, cleaned, tidied, with furniture correctly placed ready to receive visiting friends and family. It is the same in cells. In an earlier newsletter (August 2019) I highlighted the research of Dr Maiken Nedergaard (University of Rochester) who demonstrated that during NON-REM SLEEP glial cells in the brain generate a pulsating rhythm, expelling waste such as the amyloid debris associated with the onset of Alzheimer disease into the cerebrospinal fluid surrounding the brain. Refreshing sleep is essential for good health.
Autophagy
All eukaryotic (with a nucleus) cells have a complex survival cleansing mechanism known as ‘autophagy’ (the Greek means ‘self-eating’) for the removal of waste and defective and dead mitochondria (mitophagy), as well as recycling cell components. Autophagy occurs when cells are deprived of oxygen or nutrients or are damaged in some way. ATG (autophagy-related) proteins then carry the rubbish to lysozymes, tiny intracellular membrane spheres, filled with digestive enzymes which degrade the debris ready for cell recycling; this survival process conserves resources and improves cell efficiency. However the effectiveness of autophagy declines with age; the resulting disorder is now linked to the onset of neurodegenerative diseases (Parkinson’s, Alzheimer’s disease, Amyotrophic Lateral Sclerosis), cancer, non-alcohol fatty liver disease (NAFLD), diabetes, heart disease, inflammatory bowel disease and more.
Food & Fasting
Our hunter-gather ancestors didn’t eat 4-5 times each day, consuming highly processed food, sugary drinks and alcohol. They lived a very different existence, catching, killing and eating wild animals and consuming plants and berries in season. We have the same body and genes that were forged in this environment of scarcity, or occasional plenty when a massive indulgence of food was possible. It would be wise for us to intentionally stimulate the autophagic process (see table opposite) that cleanses and renews each cell in our body.
EXERCISE regularly. EAT LESS. It’s ok to feel hungry. Stop the junk food, use a smaller dinner plate or like the Okinawans say "Hara hachi bu" which is a reminder to stop eating when your stomach is 80% full.
CONSIDER FASTING. Begin with a shorter fast of 10 hours and lengthen the period of not eating. You may want to try INTERMITTENT FASTING where two healthy meals are eaten each day during an 8-hour window, with no food for 16 hours. Most lose weight. If you consider undertaking a more prolonged fasting, chat with your doctor first.
Fasting will preferentially use inflammatory fat in the liver and pancreas as fuel, improving the insulin resistance that is especially helpful in treating obesity, NAFLD and diabetes.
‘The Fast Diet’ by Michael Moseley & Mimi Spencer is a useful resource.
References available on request.