Spoiler alert: I usually start my seminars by talking about how we are all in a continual flux of our constituent cells. Don’t tell me that “people never change”… yes, they do, in fact every day a huge chunk of every person dies and is reborn. For instance, perhaps 84% of our cells are red blood cells, and each one of those cells only lives about 100-120 days (meaning that 2.4 million new cells need to be produced every second)! Not only that, our entire intestinal epithelium is completely renewed every few days, and we lose (and gain) about a Billion (Carl Sagan emphasis added here) cells in our small intestine every 20 minutes. Woah. OK, … so what happens to the cells that “leave” our intestines? They enter the part of the gut where the “food” goes. So, do we eat them? Do we eat our own cells? Are we constantly, every day, digesting ourselves?
Yes.
According to the Food and Nutrition Encyclopedia, every day 25% of the protein in our diet comes from digesting our own intestinal cells! Think about that. Today, perhaps one fourth of the protein in your diet came from digesting your own flesh!
And then I can start talking about my research.
Vincent Cannataro, Ph.D. 