Posts Tagged tradition

The reductionism of nutritional Darwinism

Michael Pollan argues in In Defense of Food that we should ignore nutritional science and stick with traditional diets. He explains,

Confounding factors aside, people who eat according to the rules of a traditional food culture are generally much healthier than people eating a contemporary Western diet…I’m inclined to think any traditional diet will do; if it wasn’t a healthy regimen, the diet and the people who followed it wouldn’t still be around. (173)

This is the dietary philosophy which Daniel Engber called “nutritional Darwinism.” The idea behind the name is that people who eat unhealthy diets will be selected out (in the sense of Darwin’s natural selection) of the human population over time.

On the face of it, it might be an appealing idea, but nutritional Darwinism is reductionist in its own way. Namely, it reduces all of human health to the ability to reproduce and raise offspring who can reproduce. If we only know that a group of people has survived on a particular diet for generations, that doesn’t tell us much about how the people tend to die, how long they tend to live, or any non-fatal health problems they may experience. And as the story of beriberi shows, groups of people have survived for generations on traditional diets that had serious nutritional deficiencies.

However, to fully appreciate the weakness of this line of reasoning, consider what it might say about the “Western diet” from which Pollan urges readers to “escape.” Although Pollan contends that this diet is a relatively recent development, it’s not obvious that it can’t survive for a while. There clearly is no shortage of Americans at reproductive age. Moreover, the “Western diseases”–the conditions such as heart disease and cancer that Pollan blames on the Western diet–tend to strike later in life, so they don’t usually interfere with people’s ability to reproduce. This means that there’s no reason to believe that the Western diet will kill off its eaters any time soon. Therefore, if the principle of nutritional Darwinism is to be believed, the Western diet must be healthy!

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Science, culture, and nutrient deficiencies

Michael Pollan writes in the first chapter of In Defense of Food,

Vitamins did a lot for the prestige of nutritional science. These special molecules, which at first were isolated from foods and then later synthesized in a laboratory, could cure people of nutritional deficiencies such as scurvy or beriberi almost overnight in a convincing demonstration of reductive chemistry’s power. (21)

Pollan doesn’t dwell on the topic of nutrient deficiencies, but I will. In their article “In Defense of Food Science,” David Julian McClements, César Vega, Anne E. McBride, and Eric Andrew Decker point out that fortified foods have played important role in alleviating a number of diseases, namely pellagra, spinal tube defects, beriberi, goiter, and rickets.

The example of beriberi, which is detailed in Kenneth J. Carpenter’s book Beriberi, White Rice, and Vitamin B: A Disease, A Cause, and a Cure, is particularly instructive. Beriberi, which is often fatal when left untreated, was so prevalent in late nineteenth century Japan that one western doctor dubbed it “the national disease of Japan.” Moreover, western doctors visiting Japan after the Perry Expedition brought about the country’s opening to the West in 1854 found evidence that the disease had been around for a long time.

In the late 1800s, it was determined that beriberi was diet-related, and shortly thereafter it was discovered that beriberi was caused by a deficiency of the nutrient now known as thiamine (vitamin B1). In the case of the Japanese sufferers of beriberi, the thiamine deficiency was related to a diet based heavily on white rice. Although rice naturally contains thiamine, most of that thiamine is found in the husk, which is removed to produce white rice. Carpenter explains the preference for white rice, “In practice, nearly everyone who eats rice as their staple food, that is, the centerpiece for each of their daily meals, prefers white rice if it is available, and eating it can be a status symbol.”

Thus, the example of white rice is one in which longstanding cultural preferences resulted in dietary patterns that were demonstrably unhealthy. This should be reason to doubt an argument Pollan will make later, that the continued existence of a diet is proof of its healthfulness. Furthermore, the subsequent success of nutrition science in curing beriberi shows that science can help improve on a diet that tradition recommends.

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Vegetarianism and tradition

Aside from the difficulties vegetarianism presents him as a houseguest, Michael Pollan has trouble reconciling vegetarianism with tradition. He writes in The Omnivore’s Dilemma,

Healthy and virtuous as I may feel these days, I also feel alienated from traditions I value: cultural traditions like the Thanksgiving turkey, or even franks at the ballpark, and family traditions like my mother’s beef brisket at Passover. (314)

It strikes me as odd that Pollan should invoke the Jewish tradition as he goes about trying to justify his hunting and eating of a decidedly un-kosher pig. This might seem like a petty objection, but I think there’s an important point here.

In planning to hunt a pig (or, for that matter, eating the “delicious barbecued tenderloin of pork” that was his last meal before turning vegetarian), Pollan has implicitly accepted the idea that traditions can be modified to suit changing circumstances. So too might the Thanksgiving, ballpark, or Passover traditions be modified to be conform to vegetarian values. Indeed, quick searches reveal that bloggers have made a vegan brisket, and that Pollan’s local baseball stadiums (in Oakland and San Francisco) have been recognized for their vegetarian fare.

Jonathan Safran Foer argues in Eating Animals that vegetarianism actually furthers the goals of culinary tradition. He explains,

The point of eating those special foods with those special people at those special times was that we were being deliberate, separating those meals out from the others. Adding another layer of deliberateness [by making those meals vegetarian] has been enriching. I’m all for compromising tradition for a good cause, but perhaps in these situations tradition wasn’t compromised so much as fulfilled. (191)

By contrast, Pollan’s feelings of alienation seem to arise from a narrower view of tradition, one that directs him to do exactly the same thing as his ancestors did. It isn’t necessarily incorrect to look at tradition that way, but that view is hard to reconcile with his eating and enjoying the pork forbidden by his ancestors’ kosher tradition.

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