Jeff's Lunchbreak: Interstellar Potatoes

Alien Food I like potatoes. A lot. I half jokingly tell people that I'm glad I was born after Europeans discovered the New World, or else I wouldn't get to eat potatoes. But, if I'd been born a thousand years ago, I wouldn't have known what I was missing. And that got me to thinking - what foods might we discover in the future that I'm missing out on, now. Most of the surface of Earth has been explored (if not by Europeans, at least by other cultures), so most of the good foods on this planet have probably already been discovered. But what about if we ever start exploring other planets? What might we find then? And that got me thinking some more - would we even be able to eat what we found on other planets. Of course, we'd probably be able to chew it and pass it through our digestive tracts, but how nutritious would it be? I don't know enough about biology to know the answer, but how flexible are our digestive systems? Are they tuned to the molecules created by the DNA based life here on Earth? I know that we need to consume certain molecules, such as vitamin C for example, because our bodies can't synthesize them on their own (so we'd probably need Earthly supplements for those). But for the molecules that we can synthesize, can we just use matter in any form, or does it already need to be assembled in a form that we can use?

Maybe this doesn't really matter for my culinary question. Since we're talking about the future here, by the time that humans have the technology to travel to other planets, we'll probably have the technology to engineer gut microbes to digest that food for us. Maybe I should go crygenically freeze myself, and get thawed out every thousand years or so to see what new and delicious foods are in humanity's pantry.

Added 2010-03-09 After I wrote this entry, I sent off the same question to a friend of mine who happens to be a biologist. Here was his response.

Good question. Actually its funny that you asked me this now because my lecture on Monday is on digestion. My short and unsatisifying answer is it depends. First, it would depend on whether alien life is carbon based. If it is, I think that there is a very good chance we could digest it unless it is in forms that our digestive enzymes cannot break down, like cellulose. In order to use the nutrients that are in the food we eat, we must break them down into molecules that are small enough that they can be absorbed. In other words, we can't directly use proteins, lipids, and complex carbohydrates, but if we break them down we can reassemble their components into the forms that we need. The enzymes we use to break down what we eat (like amylase that breaks down starch and glycogen) ARE tuned in, as you put it, to the types of food that we eat. So if alien life had some sort of complex chemistry that we do not have the enzymes to process then we would not be able to digest it. The second issue is whether it was somehow toxic, which seems to me to be reasonably likely. If alien life had a different balance of elements, which I assume it would (unless it is derived from the same origin as life on earth, which is possible) I think the chances are good that some of them would be toxic to our systems.