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Bloom is Off the Soy It's astonishing how quickly a wide range of soy-based foods and drinks has flooded our groceries and delis. Most consumers are sure they are doing the right thing by replacing dairy with soy products because they are so "health-promoting" -- especially new mothers who are feeding their infants soy-based formulas. However, there is a small group of nutrition experts who strongly disagree about the so-called health properties of soy. In fact, they fear soy might pose a danger to health, in particular reproductive well-being. I wrote about these concerns a number of months ago, but at that time large studies investigating soy were not yet available. That has changed and the results have taken many people by surprise. By far the largest study was one done on mice at the National Institutes of Health's Institute of Environmental Health Sciences. It looked at genistein, one of the isoflavones (plant estrogen substances also called phytoestrogens) contained in soy. For this study, researchers injected genistein into groups of newborn female mice at three different levels of dosages, all within the equivalency of what a human baby might drink in soy-based formula. The mice in all three groups showed disruption in the development of their ovaries. As they matured, they had irregular menstrual cycles, problems with ovulation and eventually with fertility. The mice that received the highest dosage of genistein were infertile. Those who received lower doses were sub-fertile, meaning they had fewer pregnancies and fewer pups per litter. An NIH spokesperson acknowledged that there was no way to know for certain how these findings translate to humans, but they warrant caution. Another spokesperson expressed the belief that the phytoestrogen would likely affect these children as adults, if not in childhood. The second startling study came from the American Heart Association, which formed an expert committee to review a decade of randomized studies on soy's benefits. This was especially important because in 1999 the Food and Drug Administration (FDA) gave manufacturers of soy-based foods permission to add labels that proclaimed these foods to be heart-healthy based on studies that showed consuming at least 25 grams of soy each day lowered cholesterol. Shortly after that time, the AHA recommended making soy part of a heart-friendly diet. Now, some six years later, the AHA committee reviewed 22 studies on dietary soy protein. The committee's findings: Consumption of large amounts of soy protein has virtually no effect on LDL levels, reducing them a mere 3%. Soy consumption does not raise good cholesterol (HDL) at all, nor does it show any beneficial effect on blood pressure. The committee also reviewed 19 studies on soy isoflavones alone, which were supposedly associated with relief of menopause symptoms. The review found that isoflavones do not reduce menopause discomfort nor does soy protein. Furthermore, the committee found that isoflavones do not help prevent breast, uterine or prostate cancer. (The Solae Company, which represents the industry, had already quietly withdrawn its application to the FDA to label soy protein as having anti-cancer benefits.) Or course these findings beg the question of what it was that motivated the American Heart Association and the FDA to so aggressively promote soy's benefits... but that's a subject for a different article. UNRAVELING THE CONFLICTING REPORTS Clearly these findings are a striking blow against the common beliefs about soy. To learn more about them and what was behind the previously glowing reports of soy's benefits, I called Kaayla Daniel, PhD, author of The Whole Soy Story: The Dark Side of America's Favorite Health Food (New Trends). Dr. Daniel explains that much of the previous research on soy (primarily funded by the soy industry) was based on meta-analysis studies. For meta-analyses, researchers gather a number of studies together on a given subject and average out the congregate findings. Meta-analyses are valuable for providing hints about what might be actually going on and suggestions for appropriate follow-up randomized studies, but they are not considered reliable last-word research. The first weakness in meta-analyses is that researchers can cherry pick among studies and by doing so influence findings, says Dr. Daniel. And since findings are averaged out, a negative study or two will be overwhelmed by favorable ones. Many years ago, she says, there were some solid studies on soy, but they were "put out to the field" in order to find ways to modify the soy protein, what is left after oil is extracted from the beans to turn it into acceptable animal feed. These studies investigated what amino acids, fatty acids, vitamins and minerals should be added to soy protein to make it safe and to protect reproductive function. Dr. Daniel adds that the information gained from these studies has not made its way to many of the soy-based products that humans now eat. The Soy That's in Our Food To find out more about the soy that is in our food supply I called Carolyn Dean, MD, ND, who has done extensive research on a number of digestive-related topics and is author of IBS for Dummies (Wiley). Dr. Dean points out that the wide varieties of soy-based foods require extensive processing to get them to the state in which they can be used as the foods now on our shelves -- they are far from "natural." The beans are cooked, crushed and heated to high temperatures and then put through a solvent extraction process to remove the oil. The now defatted meal is mixed with sugars and an alkaline solution to remove the fiber and the resulting curds are spray dried at high temperatures, which does two things -- produces high-protein powder... and peroxides the oils making them pro-inflammatory. The end result is food that is bereft of vitamins and likely minerals, she says, and far removed from being a natural wholesome food. And there are other problems. Because soy has a high level of phytic acid, it blocks digestion of grains, which are an important source of minerals. Additionally, soy contains trypsin inhibitors and these interfere with protein digestion. Adding to these problems, the body does not absorb the B-12 in soy, which in turn creates a nutritional void for vegetarians who consume soy protein as a way of providing themselves with this important B vitamin. Even so, some soy products are reasonably healthy. Dr. Dean, who also studied Chinese medicine, says that the Chinese did not eat soy until they discovered that fermenting would turn it into a useful food. In fact, fermented soy is largely the type of soy that Asians consume today. Fermenting involves treating soy with a mold for a day or so. Fermented foods include tempeh (not to be confused with tofu, which is not fermented), which has a nutty mushroom taste... miso... natto... and tamari sauce. However, because soy exists in so many foods today as vegetable oil, binders and the like, even people who are wary of soy probably consume some of it almost daily. Consequently, Dr. Dean advises limiting fermented soy product consumption to not more than every third day. The soy industry has ballooned in recent years and now represents more than a billion dollars in sales per year. You can expect to hear much more from both the industry and independent researchers in the future concerning soy and health issues. I'll be sure to keep you up to date. In the meanwhile, while searching your food store for high-protein foods, take a pass on the ones "enriched with soy protein." Be well,
Think you have memory challenges? Imagine memorizing all those complex picture-characters in Japanese writing. Maybe that's why hundreds of Japanese patients were so grateful recently when a doctor reversed their short-term memory loss with a simple tea made from eyebright -- an herb that you can grow in your own garden. While eyebright as a memory booster is new, its power to help vision has been famous since the 14th century. It strengthens the optic nerve, making the eye less vulnerable to cataracts. This nerve-boosting also may help the brain, which, after all, is made up of nerve cells. Read on...
Sources: Bloom Is Off the Soy Kaayla T. Daniel, PhD, author of The Whole Soy Story: The Dark
Side of America's Favorite Health Food (New Trends), and a board-certified
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