Wednesday, May 19, 2010

Killer Tofu

This week's "Tip Hero" newsletter contained a link to a tip I wouldn't have considered particularly controversial: "A Cheap and Healthy Meat Substitute." The article was about TVP, an inexpensive meat substitute made from soybeans, and most of the comments focused on ways to use TVP and other soy products. However, one of the comments seemed to wander off into the realm of, well, wacko-dom. An excerpted version:
Arrrggghhhhh, soy?? Has anyone ever read "The dark side of soy"? Soy is actually toxic in the bean form and they acid wash it, and do other nasty things, to make it edible at all. It's used as a filler, just like all the chemicals and such in our foods. Soy washes away all the good stuff in our digestive tracts, plus mimics estrogen in our bodies....Don't believe what they tell you out there, they are not out for our health and the government, the FDA, and the Medical field is all about keeping us sick. The only way "some" say it can be used safely and might have benefits, is when it's "fermented" soy. However, there are still those who will argue it's not safe at all.
Now, I already knew for a fact that soy doesn't need to be "acid washed" to be edible, because I've eaten it straight from the pod as edamame, so I was naturally suspicious of the comment as a whole. It sounded like such blatant pseudoscience that my first impulse was to go to and "The Straight Dope" looking for an article debunking these claims. To my surprise, they had never been addressed. I then tried Googling phrases such as "soy inedible," "soy toxic," and "soy safety," but I didn't find a single article on the safety of soy that seemed to be from a reliable, unbiased source. I found one article by alternative-health guru Dr. Andrew Weil, but I hesitated to cite him as a source, since so many people consider his views a bit "fringe" already. An article from the Mayo Clinic looked promising, but it turned out to be about soy-based supplements, rather than soy foods. Eventually I managed to turn up an article from the NIH's National Center for Complementary and Alternative Medicine, which said only that "Soy is considered safe for most people when used as a food or when taken for short periods as a dietary supplement." (However, it also noted that research is unclear about whether soy can affect estrogen levels, so women who are at risk for breast cancer and other hormone-dependent cancers should "be particularly careful about using soy." It wasn't clear whether "using soy" referred to eating soy foods or taking soy supplements.)

I was surprised at how hard it was to find a single reliable source that evaluated the health risks and benefits of soy objectively. However, one thing I do know is that from an ecofrugal standpoint, the benefits of soy products aren't always clear-cut. For example:
  • Soy isn't always cheaper than meat. A one-pound slab of tofu costs $1.49 at Trader Joe's. A pound of chicken or pork can cost a dollar or less on sale at the local Stop & Shop. (Free-range chicken, on the other hand, starts at $2 a pound.)
  • Tofu isn't a particularly lean source of protein. According to the USDA's National Nutrient Database, half a cup of raw, firm tofu has about 20 grams of protein and 11 grams of fat. A whole cup of white-meat chicken, by contrast, has 27 grams of protein and only 4 grams of fat. (Hardly surprising, when you consider that soybeans are grown largely for oil.)
  • On the other hand, soy does seem to come out ahead from an ecological standpoint. According to Wikipedia, soy farming produces "up to 15 times more protein per acre than land set aside for meat production."
On the whole, including soy foods in my diet seems to be a reasonably ecofrugal choice, and the balance of the evidence suggests that it should do my health more good than harm. But I can't help wondering whence comes all this animosity toward the humble soybean. Are all the anti-soy sites secretly funded by meat producers?

EDIT: Here's a little illustration supplied by Brian to go with this post.
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