Introduction to Nanotheology, Part 3: Lenten Fasting

In the spirit of the season, I'd like to give a sketch of what exactly I mean by nanotheology. Most people, however Protestant they may be, give up something for Lent as a form of fasting. One year we gave up TV on half the days of the week. I know someone who gave up chocolate, or caffeine. Until the hairshirt comes back in style, these kind of things are the normal, evangelical-style Lent I've observed, and it's good. What I want to point out is that unless you're addicted to caffeine (and that's another subject entirely) none of these are physical deprivations, they're more habitual, emotional, spiritual, etc. But if you give up food itself for a considerable period, you end up with a change in your life that's so drastic that your body itself changes how it works, or more specifically, the fuel that it runs on.

Here's how the biochemistry works: when you eat something, that's literally wood for the fire. You "burn it" by combining carbon with oxygen, and you get carbon dioxide, water, and energy out the other end. The chemistry of the process is just like when you place a match to a piece of newspaper, but in a much more controlled fashion. First you've got to chop up the "logs" to make them small enough to burn (more on that later), but then you've got to get the chopped-up food to the brain and muscles, which are burning molecules like there's no tomorrow in their duty to keep your body running. To transport from the stomach or liver to the brain or muscle, you've got a nice network of roads that you know better as the circulatory system: the blood. The thing is, your blood is mostly water, a river that connects all your organs. So you need to make sure the "wood" you're sending to the brain will "float" in the water, or in chemistry terms, will mix with your watery blood so it stays in the river and off of the banks. The best molecule for this is a sugar molecule, glucose.

Glucose is a circle of 6 carbon atoms bristling with 6 oxygen atoms on the outside. Because water itself is made of oxygen (plus 2 little hydrogens, hence H2O), the oxygen atoms mix well with the water and keep the glucose "afloat." Then the brain can just pull in glucose from the blood and burn, baby, burn. So after you eat a big meal with lots of sugar, your blood glucose goes up and your brain has a field day (much like when I gave Red Bug and his brother, who I think I'll call "Green Dog," hot chocolate at 8pm the other night; not a good idea, by the way).

The thing is, what happens once the food is digested and there's no more sugar in the stomach? The liver can bring sugar out of storage, it can make a little more sugar on its own, and it can burn fat for its own energy, but for very interesting reasons I can't go into right now, it cannot make sugar from fat. Plants can do that, but we can't. So if the liver runs out of stored glucose, your blood glucose drops, and if it drops too far, you're in danger of the brain shutting down from lack of food, otherwise known as a diebetic coma.

Good thing there's a backup system. You see, one of the reasons we use glucose to feed the brain through the blood is that fat, although it's great at providing energy, doesn't "float" or mix well with water. It's like, well, oil and water. So when the glucose drops we can't send fat through the blood to feed the brain, but the body has a second-best option: tiny chopped-up fat molecules. If the fat is made smaller, and a few oxygens are stuck on it for good measure, it just barely floats and is able to mix with the blood long enough to make it to the brain. The energy-starved brain says "Not my favorite, but it will do" and feeds the chopped-up fat to its mitochondria, which burn it and turn it into energy (again, mitochondria are another topic for another day!).

This back-up system, these chopped-up mini-Me fat molecules, are somewhat quaintly called "ketone bodies," and if you remember any organic chemistry, you'll recall that ketones are a bit nasty. One of the "ketone bodies" is actually acetone, which you may know better as nail polish remover. So it's obviously not physically ideal to be running your brain off nail polish remover, but it's good enough for government work. Also, the ketone bodies aren't able to carry as much energy as glucose, so the pieces of wood are smaller and the resulting "fire" is not as big. If you've ever gone hungry, you find yourself not thinking quite as clearly -- I think some of that is because "This is your brain on ketone bodies." Oh, and lest I forget, these ketones are acidic. So not only are they not as good at their job, they also lower the pH of your blood, not quite to the level where you have a sudden urge to hiss and fight Sigorney Weaver, but it's still not a good thing. People with lots of ketones in their blood will be in a state of both "ketosis" and "acidosis." I like how "ketosis" is one letter removed from "kenosis," the Greek word for "emptying" that describes what Jesus did in his first Advent (see Philippians 2:5-8). Physical emptying and spritual emptying are two sides of the same coin, or two angles of viewing the same object.

All this is to say, when your stomach and liver run out of glucose, and your brain is being fueled by fat, it is feeding off a sub-standard low-octane fuel ... and that is a physical difference that may cause the brain itself to run differently, physically. You experience this as a different feeling when you're fasting, and maybe even you think different thoughts. I suspect these differences are actually conducive to "spiritual things" ("pneumatikon" in Greek, see 1 Cor 12:1) in a direct cause-and-effect manner. The fact that they have a physical cause does not exclude a spiritual effect -- the two are linked, just as our brains are intimately linked to our spirits, even in the same cause-and-effect kind of relationship.

So, when thinking about fasting, consider the ketones, how cutting out one thing from your diet is one kind of good, but cutting out everything from your diet for some hours, or for a day, may add a new dimension of mental space for God to work in. Since that's the point of fasting, consider making it more "real" by physically going without the food you need (diabetics need not apply!).

Giving up food as a fasting discipline. I wonder why I haven't heard of this before? Oh, right, that's because Jesus said not to talk about it too much. Therefore ...