Everything we eat is bad for us -- or so it seems from the reports we read of scientific studies. Everything we eat seems to cause, or be "associated with," cancer, diabetes, heart disease, obesity or some other undesirable sickness or syndrome.
Is anyone out there in media-land trying to put these studies in perspective? Can anyone offer us some reassurance that we're not poisoning ourselves every time we sit down at the table?
Thankfully, yes. I've written in praise of Tamar Haspel before (http://tiny.cc/…). I rise to salute her again. Her Washington Post piece (http://tiny.cc/…) assessing the health risks of potatoes should be taught in journalism-school classes. It's a model of how to assess conflicting evidence, reach a measured conclusion and do it in a way that holds readers' attention.
A high point of the article is Haspel's comparison of potatoes and broccoli. Potatoes, she writes, produce about 15 million calories per acre, versus 2 million for broccoli, while holding their own with broccoli on nutrients: half the calcium and vitamin C per acre, none of the vitamin A, but three times the iron, phosphorus and potassium.
"Here's what it boils down to," she writes. "Broccoli delivers nutrients without attendant starch calories, and potatoes deliver nutrients with them. If you're a privileged American with a weight problem, broccoli's a great choice. Green vegetables are, calorie for calorie, the most nutrient rich foods we can put on our plate. But if we're trying to feed a planet, we have to look at how to maximize both the calories and the nutrients we can grow on the land we have, and potatoes do that very well."
The potato, Haspel thinks, suffers in comparison to vegetables because it's often mis-classified as one of them. It should, she says, be classified as a grain. Lumped into that category, it compares well. Potatoes, she argues, are richer in nutrients than oatmeal.
But what about those scientific studies linking the potato to diabetes, hypertension and obesity? Haspel raises interesting questions about their validity.
They're based, she says, on "research on people who are asked what they eat and then tracked until something bad either happens or doesn't." Haspel doubts the accuracy of such self-reported diet data. She filled out one of the leading such surveys herself. It asked her questions she couldn't answer, like how often she'd eaten a half-cup serving of cabbage over the past year. She just didn't remember.
Even assuming accurate data, she thinks the studies can be faulted. It's more than just the slurring of correlation and causation, a problem with a lot of studies of the healthiness of food. These studies, she argues, fail to take into account "the non-potato related ways" people who eat a lot of potatoes differ from people who don't.
Potatoes could, for some of their fans, be part of a pattern of unhealthy lifestyle choices--Haspel mentions "cheeseburgers and Survivor reruns." She wonders, too, whether the results indict not potatoes but how people eat them -- deep-fried, or with plenty of butter and sour cream.
It was at that point in the piece that I said to myself, "Guilty as charged." French fries? Guilty. Sour cream and butter on bakers? Guilty again. But instead of throwing myself on the mercy of the court, I pray to the goddess Moderation. Actually, I assume I have the goddess's blessing: I refuse to believe that occasional indulgences will kill me, as long as they really are occasional.
There aren't, alas, studies elevating French fries and loaded baked potatoes to the status of health food. The fair-minded Haspel makes her own bow to Moderation, but even she can't extol the health-food benefits of French fries.
But she has more than exonerated the potato itself. In her report spud lovers have gotten the best they can hope for: A judgment by someone who calls herself "very pro-green vegetable" that, upon reading the studies and talking to people on both sides of the issues, she finds potatoes aren't bad for us. These days, that's something.
Urban Lehner can be reached at firstname.lastname@example.org
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