Not so long ago I read Michael Pollan's In Defense of Food. While I was naturally disposed towards agreeing with most of his points, it was an educational read nonetheless, and I highly recommend it. In the meantime, I want to reflect on some of the central ideas, especially now that I'm cooking (gasp) for myself.
It is fascinating that, despite the incredible progress of medicine, in many ways people have actually gotten unhealthier over the last century. Sure, lives are longer, and the older people get, the more likely they are to manifest the horrible diseases that are lurking somewhere in their genetics. But even younger people are less healthy. There's a lot more cancer a lot earlier in people's lives, and obesity has become a huge problem, especially in the United States. Pollan, thankfully, doesn't take the silly "Americans are stupid, fat, and lazy" tack that you're likely to hear on a talk show. Rather, he approaches the problem from a nutrionist perspective.
In short, the generally low quality of health in America comes from one primary source: our fascination with nutrition. Instead of eating food, we try to consume nutrients, and, as a result, we end up ingesting lots and lots of processed food-like-substances wraught with chemicals and plastics and pesticides and hormones and all kind of nasty stuff. There's obviously an anti-corporate sentiment in opposing mass-produced, highly-processed food products, but Pollan is also concerned with food science as well.
There is a kind of assumption among food scientists that we can simply figure out what nutrients a person needs to survive, and, ultimately, we could just create a pill that would sustain a human being without the need to eat. Ignoring the cultural and social implications of this model, Pollan points out that there are some serious scientific issues as well. The reality is, we simply don't know what exactly is in our food, and why it is so good for us. What we do know, on the other hand, is that human beings co-evolved with fruits and vegetables and even other animals (to a degree) so that those things would be good for us. It was beneficial for a fruit if a human would eat it and thereby spread its seeds, and it was beneficial for a human to eat so it could, you know, live. As a result, fruits developed all kind of attractants and hidden benefits and, in a cunning and devious move, subtle hidden things that we need to survive.
The problem is, we can't simply extract all of those things and figure out how they operate in our bodies. Anatomy, medicine, nutrition, evolution, and all the sciences involved are simply not advanced enough to adequately understand what food really is. There are complex interactions in the process of digestion that we cannot isolate, there are relationships between parts of the fruit that we do not appreciate, and there are nutrients that, probably, we haven't yet discovered. The evidence for this lies in the history of the science of food. Every time we think we've cracked the puzzle, we discover there's another layer of complexity we never considered before (much like, I don't know, just about every other science).
That's not to say research into food is not meaningful or valuable. Of course we should be trying to discover the micronutrients that make up our diets (just as we try to discover the sub-atomic particles that make up our universe). The problem lies in the translation of food science into practice. Because food science is tied in with food corporations, it is in their interest to perpetuate the idea that science knows what you should eat, while your mother (or grandmother) doesn't. This is - as Pollan points out - a rather severe reversal of the previous few millenia of human history, during which people may have been unhealthy for many reasons, but bad nutrition was rarely one.
I won't try to reproduce the whole argument, but I do want to emphasize this main point of Pollan's. Almost every cultural diet in the world produces good health, despite the wide variety in focal nutrient. The "Western Diet" of processed cereals, lots of red meats, candy, and soda does not. But it's not just candy and soda that is to blame. It's really, more than anything, our emphasis on processed rather than whole foods. Processed foods, by definition, cut out nutrients in favor of others, and try to do things like reduce fat, fortify with vitamins, preserve freshness. The problem is, none of that is really any good for you. An apple, some salad, and maybe a small piece of chicken will always be better than even a "healthy" breakfast bar.
Pollan's catch phrase is "Eat food, not too much, mostly plants." That is exceedingly sensible advice, because it could easily be translated thus: "eat the way human beings evolved to eat." Just because the grocery store says your cereal is "heart healthy" doesn't mean it actually is.