Autophagy: Self-Eating

No, this isn't some radical new kind of low-carb diet.  It's a cellular process I touched on in a previous article, and I'll be talking about it again soon, so I thought it'd be useful to cover it on its own.

Cells age, like everything else.  Their internal structures, membranes, nuclei and even their DNA suffer damage over time, largely from free oxygen radicals.  Cells have several solutions available to them for dealing with this damage.  The first line of defense appears to be autophagy, which describes several different processes for handling just the damaged bits, rather than self-destruction, or apoptosis.

This process is crucial for the prevention of cancer, heart disease, various neurological disorders, and other diseases, and most effects of aging can be blamed on its failure.  Consider the opening statement of this introduction: "Protein quality-control, especially the removal of proteins with aberrant structures, has an important role in maintaining the homeostasis of non-dividing neural cells."  The paper is about neurology, but the same statement is true of other cells.

What does all this have to do with a low-carb diet?  The process is regulated by a protein called mTOR, which in turn is regulated by our old friend insulin.  Take a moment to consider this, from the list of insulin's effects from that Wikipedia article: "Decreased autophagy - decreased level of degradation of damaged organelles. Postprandial levels inhibit autophagy completely."  I had to look up "postprandial".  I figured it meant some crazy-high insulin level only seen in hospitals, but it means "after a meal".  That can only mean after a typical meal, since a low-carb meal by design doesn't spike your insulin levels.

What this means is that when you eat carbohydrates, at least in quantities that constitute a meal, this critical process is completely shut down.  After years of doing this habitually, you become insulin-resistant as we discussed before, and in all likelihood you have postprandial-looking insulin levels for all your waking hours.  You almost entirely lose its protection against the diseases I listed earlier and almost certainly many more that haven't yet been identified.  You age much more quickly.  This last tidbit was identified, with brief commercial success, some time ago, but odds are this is the first time you've heard about it, much less had it explained.  And I haven't even gotten started - there's a lot more to cover on the subject of aging.

Which reminds me, I'm going to be talking about autophagy a lot in the future, so I wanted to cover the basics in an article I could link back to, instead of trying to explain the same complicated issue each time it comes up.  I'll be doing more of that kind of thing, partly to try to cut down on the length of my posts.  Let me know in the comments how I'm doing on the balance of good info vs. readability and I'll keep tweaking accordingly.