When I was in college, one of the many jobs I had was loading trucks for UPS. Boxes would move throughout the warehouse on a series of conveyor belts. The dock I worked on had five 18-wheeler trucks. Those trucks once full would leave Columbus and head off to different regions of East Ohio. My truck was for Zanesville, Ohio.
As packages heading for East Ohio would move to our area, a worker on a platform would check the city and zip code, and then push the box onto the appropriate slide which fed one of the five trucks. During my 3 hour shift, boxes would pour into my truck. My job, prior to loading, was to confirm it belonged in my truck by inspecting the city and zip code on every parcel. If the box was mistakenly put in my truck, it was my responsibility to get it out. Also, if the box was damaged it had to be removed for repair.
The boxes did not trickle in at a steady rate. They came in fast, then slow, then medium, then fast again and there would be times when no boxes came into my truck. When things slowed down or I had no boxes to load, I would use that time to get out any parcels with bad zip codes and fix any damaged parcels.
Where is this blog post going?
Last year I learned about a cellular process called autophagy and it reminded me of my job loading trucks. From Cellular Autophagy by Arthur De Vany:
Autophagy (self eating or consumption) is a crucial process in the cell. The cell consumes and recycles damaged internal material; this is an energy sparing process and important for scavenging old and damaged material within the cell. Autophagy is an important element in energy management and damage repair. The energy and protein content of damaged material is used to fuel rebuilding and cellular energetics.
The process seems to be triggered when the energy content of the cell declines so that the cell literally consumes itself. It goes after the damaged materials first, so there is a strong link between repair of damaged tissues and fasting or low energy state in the cell. So, it you are over-fed you down regulate cellular repair. You want to go hungry episodically to turn on cellular autophagy and repair those damaged tissues.
In short, cells will live happily off the nutrients flooding into them until they stop coming. At that point, they start a clean and repair process. The cell feeds off their own damaged material for fuel. If the cell never gets a break from the flood of nutrients, it won’t devote resources toward autophagy. Why feed off a damaged tissue for fuel, when new nutrients are still entering the cell?
This to me sounds a lot like my job at UPS. As long as boxes (nutrients) poured into my truck (cell), I didn’t have the resources to remove (clean) parcels with bad zip codes (toxins) or fix (repair) damaged boxes (cancers).
When I first started loading trucks, I would have nights where 5-6 parcels would arrive in Zanesville incorrectly or damaged (unhealthy rate). Eventually, I got better and would have just 1-2 over an entire week (healthy rate). My truck was cleaner and my error rate plummeted.