Science and nutrition

It occurs to me that most of what I write about here is prompted by something happening currently in science, so perhaps it’s appropriate for me to be clear about my fascination with science.  It’s an interest I’ve enjoyed my whole life, although I have never pursued science formally, either in school or as a career.  (Perhaps in the next lifetime?)

When I say I’m fascinated by science, I mean several different aspects of science: the scientific way of thinking, the practice of science, and finally some of the results that come from the thinking and the practice.

It’s called “scientific inquiry” because it starts with a question—not a big question (the meaning of life will not be decided by a science experiment any time soon).  To be useful—in other words to contribute to what we know about a topic—the question has to be crafted in such a way that its answer is as simple and unambiguous as possible.  I don’t mean to suggest that science only deals with simple ideas, but that the practice of science requires teasing out small-enough components of a topic that they can contribute an (ideally) irrefutable bit of knowledge to the whole of what we know, what we think we know, or what we know we don’t know . . . .

In some areas, science has contributed a lot to a body of knowledge—think gravity, or navigation, or the earth’s relationship to the sun, etc.  In others, especially areas where technology has only recently provided tools of discovery, we are starting to see only the smallest jigsaw puzzle pieces of information, and those tiny pieces are not yet enough to put together anything like a whole picture. For example, nutrition.

In Food Rules, Michael Pollan points out that in this area, science is very young.  He says we would be better served by looking to custom, as in the wisdom of our grandparents’ food habits, or in the absence of grandparently wisdom, to almost any set of defined cultural rules about food, rather than basing food choices on anything that science can tell us about the relationship between our bodies and our food.

Food Rules, by the way, is a delightful quick read, full of cute one-liners that sum up his philosophy of food. Unlike his other books, it’s not going to change the hearts and minds of folks who prefer their food chemically seasoned and highly packaged, but if you’re already part of the choir, it’s great fun.

While I agree with Pollan, I still like reading about nutrition, seeing all those new and surprising little bits of information coming together.  It’s only human to get excited about new information.  The trouble starts when we assume untested connections between all the little pieces—or when we blame science for jumping to the wrong conclusions based on the evidence so far.  I’m thinking about the butter vs. margarine comparisons; I read about the evidence that margarine is a healthy alternative, back in the day. I didn’t believe it then, but I suspect that had less to do with the science than with my own instinct about food.

A lovely book that deals with the science of nutrition in an honest and clear way is Dr. Walter Willet’s Eat Drink and Be Healthy. He presents conclusions about nutrition and food, based on science, but he is also careful to acknowledge that science has not given us the whole picture—that day is a long way off.

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