Sunday, February 04, 2007

Eat food. Not too much. Mostly plants.

Three simple sentences from Michael Pollan, that sum up a long, but completely fascinating article in the New York Times. This being the NYT, it will stop being free soon, so even if you don't have time to read it right now, I highly recommend printing out a copy or saving it to your computer for later.

The article chronicles the rise of "nutritionism" as an ideology in America, and how - for all our obsession with nutrients - we're fatter and unhealthier than ever before. The three sentences in the post of this title sum up his response and suggestion to counter that ideology. Definitely a must read. Here are some of my favorite bits.

On nutrients vs. food:

It was in the 1980s that food began disappearing from the American supermarket, gradually to be replaced by “nutrients,” which are not the same thing. Where once the familiar names of recognizable comestibles — things like eggs or breakfast cereal or cookies — claimed pride of place on the brightly colored packages crowding the aisles, now new terms like “fiber” and “cholesterol” and “saturated fat” rose to large-type prominence. More important than mere foods, the presence or absence of these invisible substances was now generally believed to confer health benefits on their eaters. Foods by comparison were coarse, old-fashioned and decidedly unscientific things — who could say what was in them, really? But nutrients — those chemical compounds and minerals in foods that nutritionists have deemed important to health — gleamed with the promise of scientific certainty; eat more of the right ones, fewer of the wrong, and you would live longer and avoid chronic diseases.
The perils of reductionism:
If nutritional scientists know this, why do they do it anyway? Because a nutrient bias is built into the way science is done: scientists need individual variables they can isolate. Yet even the simplest food is a hopelessly complex thing to study, a virtual wilderness of chemical compounds, many of which exist in complex and dynamic relation to one another, and all of which together are in the process of changing from one state to another. So if you’re a nutritional scientist, you do the only thing you can do, given the tools at your disposal: break the thing down into its component parts and study those one by one, even if that means ignoring complex interactions and contexts, as well as the fact that the whole may be more than, or just different from, the sum of its parts. This is what we mean by reductionist science.

Scientific reductionism is an undeniably powerful tool, but it can mislead us too, especially when applied to something as complex as, on the one side, a food, and on the other, a human eater. It encourages us to take a mechanistic view of that transaction: put in this nutrient; get out that physiological result. Yet people differ in important ways. Some populations can metabolize sugars better than others; depending on your evolutionary heritage, you may or may not be able to digest the lactose in milk. The specific ecology of your intestines helps determine how efficiently you digest what you eat, so that the same input of 100 calories may yield more or less energy depending on the proportion of Firmicutes and Bacteroidetes living in your gut. There is nothing very machinelike about the human eater, and so to think of food as simply fuel is wrong.
Making things worse:
No one likes to admit that his or her best efforts at understanding and solving a problem have actually made the problem worse, but that’s exactly what has happened in the case of nutritionism. Scientists operating with the best of intentions, using the best tools at their disposal, have taught us to look at food in a way that has diminished our pleasure in eating it while doing little or nothing to improve our health. Perhaps what we need now is a broader, less reductive view of what food is, one that is at once more ecological and cultural. What would happen, for example, if we were to start thinking about food as less of a thing and more of a relationship?

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