The Whole Story?
Half truths and untruths do not a whole story make
The Whole Soy Story: The Dark Side of America's Favorite Health Food
By Kaayla T. Daniel, PhD, CCN
NewTrends Publishing, Inc., 2005
Hardcover, 440 pages, $41.95 Cdn.
REVIEWED by SYD BAUMEL
If you've ever wondered how a slick prosecutor would throw the book at a beleaguered health food, this book's for you. But reader beware: there's no defense attorney in the courtroom that is The Whole Soy Story. Unless you're an expert on the voluminous science of soy or have a few months to pore through medical journals fact-checking author cum prosecutor Kaayla Daniel's forty-four pages of references (and the important references she left out), you may find it hard not to be bamboozled by her slick 394-page indictment. But if you do know enough about the science of soy to catch Daniel attempting to pull the wool over your eyes over and over again, you'll write this book off as an outrageously tainted resource that can't be trusted.
It's not entirely surprising, given Daniel's background.
Most of the so-called “soy-bashing” you can find on the Internet and in print can be traced to Sally Fallon and Sue Enig, the food activists who run the Weston A. Price Foundation, and lately to their protegee and fellow Weston Price board member, Kaayla Daniel. The Whole Soy Story is edited by Fallon who owns the small book company that publishes it.
According to the Weston A. Price Foundation's website, its mission is “to disseminate the research of nutrition pioneer Dr. Weston Price....Dr. Price's research demonstrated that humans achieve perfect physical form and perfect health generation after generation only when they consume nutrient-dense whole foods and the vital fat-soluble activators found exclusively in animal fats.” (Emphasis mine.)
For Weston A. Price Foundation food activists, the 1930s research and speculation of a Cleveland dentist have translated into an aggressive 21st century bias against plant sources of fat and protein. Soy – a major competitor with the butter, lard, pork and other animal fat and protein sources promoted by the Foundation – is squarely in their sights. The Weston Price gang is so determined to throw everything they can at soy and hope it sticks that they spin and distort the evidence to the point of making their critiques useless for consumers who hunger for a fair reckoning, for the real whole story. Like Fallon and Enig's articles, Daniel's book teems with one-sided errors, exaggerations and half-truths. I will give a few examples here. For more debunking of the Weston Price Foundation's assault on soy, see foodrevolution.org/what_about_soy.htm by John Robbins and the wave of outraged letters to the editor provoked by an abridgement of Daniel's book that appeared in Mothering Magazine in 2004 (mothering.com/sections/extras/soy-letters.html).
- Building her case mostly on a selective reading of animal studies (a common thread throughout the book), Daniel suggests that the rise in soy consumption in the West could be a cause of rising thyroid cancer rates. “Soy can almost certainly be blamed for at least some of the increase in thyroid cancers in that soy isoflavones [weak, estrogen-like compounds found naturally in soy] induce both goiters and thyroid tumours,” she asserts. I searched Medline (the index of the world's biomedical research) for an unbiased overview of the research on “thyroid neoplasms” (benign or malignant thyroid tumours) and “soy.” I found just three papers, none of which Daniel thought important enough to tell her readers about (ironic, because Daniel is always quick to accuse soy-friendly scientists and “soy apologists” of suppressing evidence – even when they're not: for example, see the letter from Dr. B. L. Strom in Mothering). One study found that high doses of soy isoflavones failed to increase the effect of a thyroid carcinogen in rats. In the other two papers (here and here), researchers from the Northern California Cancer Center sought to find out why Southeast Asian women living in the United States have a high rate of thyroid cancer. Soy wasn't one of the reasons. Women who consumed the most soy had nearly half the risk of those who consumed the least.
- Daniel cites a five-year clinical trial in which six out of 179 postmenopausal women taking a very high dosage (150 mg) soy isoflavone supplement developed endometrial hyperplasia. None of the 197 women who took a placebo did. “Endometrial proliferation is a precursor of cancer,” Daniel warns, implying the women can look forward to a date with the oncologist. She doesn't mention that all of them developed the relatively benign, non-atypical form of endometrial hyperplasia. Research suggests this condition carries a 2% risk of progressing to endometrial cancer - little different from the 1 to 2% risk for women in general. Nor does Daniel reassure her readers that, a year earlier, a study published in the Journal of the National Cancer Institute found that women who had spontaneously consumed the most dietary soy isoflavones were 40 percent less likely than those who consumed the least to have been diagnosed with endometrial cancer. Among the postmenopausal women in the study (they're at highest risk), soy was associated with a 56% lower risk. According to the authors of the study: "Only one [other] study has directly examined the effects of phytoestrogen-rich foods on endometrial cancer risk (16). In Hawaii’s multiethnic population, greater consumption of tofu alone or in combination with other soy products was associated with a 50% reduction in endometrial cancer risk."
- Daniel goes to great lengths to convince readers that soy will put them at risk for pancreatic cancer. “As for the rising rate of pancreatic cancer,” she writes, “scientists have known for half a century that trypsin inhibitors in soy protein put stress on the pancreas, contributing to and possibly causing pancreatic cancer (see Chapter 16).” In a pretense to objectivity, she advises: “As yet, human studies do not clearly connect soy protease inhibitors to pancreatic cancer. However....” Not included in Daniel's “howevers” (notably, soy seems to make the pancreas secrete more digestive enzymes) are any of the studies that have actually looked at soy consumption and pancreatic cancer in humans.
- In a 1996 study from Sapporo Medical University in Japan, people diagnosed with pancreatic cancer were significantly more likely than healthy controls to a) eat more “meats and animal viscera” and b) eat less “vegetables and the traditional Japanese foods, e.g., tofu, deep-fried tofu, raw fish, and tempura.”
- Eight years later, in a similar study from the same institute, the researchers found that "consumption of fish, all soybean products, tofu (bean curds), and natto (fermented soybeans) was associated with decreased risk" of pancreatic cancer. Comparing subjects who ate the most (top 25%) with those who ate the least (bottom 25%), the risk reduction was approximately 50% for fish, tofu and all soybean products combined - and 75% for natto. Moderate meat consumption doubled the risk compared to low consumption.
- Finally, in a 1988 American study that followed 34,000 healthy California Seventh-day Adventists for seven years, "increasing consumption of vegetarian protein products, beans, lentils, and peas as well as dried fruit was associated with highly significant protective relationships to pancreas cancer risk." While I've only read the abstract of this study, among Seventh-day Adventists - a large proportion of whom are vegetarian - "vegetarian protein products" and beans largely equate to soy. Indeed, the abstract attributes the anti-cancer effect to "frequent consumption of vegetables and fruits high in protease-inhibitor content." Ironically, it's these protease inhibitors - which abound in soy - that Daniel uses weak animal and human evidence to smear as instigators of pancreatic failure and cancer. If only she had told her readers about the studies that "clearly [fail to] connect soy protease inhibitors to pancreatic cancer."
- Daniel is constantly alleging or insinuating that scientists who publish soy-friendly research are in the pocket of the soy industry. None of the three soy-positive studies above for which I was able to find funding information online declared any support from industry. Rather, all or most support came from the National Cancer Institute of the United States.
Among doctors like Andrew Weil and scientists with no axe to grind, the prevalent view is that one, two, or even three servings of soy per day are safe, nutritious and possibly preventive of such diseases as prostate cancer and osteoporosis. (Some soy-friendly doctors like Andrew Weil are wary of highly processed soy protein “isolates,” “concentrates” and similar refined soy products. Daniel demonizes them as one step up from toxic industrial waste.) There are only a few caveats in most scientists' minds: soy eaters with hypothyroidism may need to up their dosage of thyroid hormone; those who are iodine-deficient may become hypothyroid if they eat too much; and soy may add fuel to the fire of estrogen-positive breast cancer (or it may fight or prevent it – the jury is out).
While the vast majority of studies of soy and health are neutral or positive, it has to be said that a small proportion of weak, preliminary or otherwise inconclusive studies suggest soy may increase the risk of other health disorders. These include bladder cancer; leukemia and developmental disorders in fetuses and infants overexposed to soy; and Alzheimer's disease in adults. I know that sounds scary, but statistically one would expect one in every 20 studies to give a negative finding about soy by chance alone. Even scarier, in my view, is a health book that persistently misleads and manipulates readers while pretending to enlighten them.