special concerns about soy

[Sportsmedjosh]

We include soy as one of the World's Healthiest Foods, and for good reason. It's the most widely grown and utilized legume in the world, with about 13,000 years of cultivation and over 5,000 research studies. There are studies that show soy to help regulate blood sugar, blood pressure, and estrogen balance. And there are studies showing soy intake to help prevent colon, breast, and prostate cancer, as well as atherosclerosis and post-menopausal hip fracture. It's seldom the case that a whole, natural food can be this widely used and studied for such a long period of time and have predominantly negative impact on our health.

Like all foods, soy is not a "magic bullet" and needs to be incorporated into a person's overall meal plan in a balanced and individualized way. We believe that soy needs to be eaten in moderation like all foods, as it is in Asia where it has been linked with promoting health potential. In Japan, for example, individuals seldom consume large quantities of soy at one time, as has often become the case with a "burger-replacement" type approach taken in the United States. The research makes it clear that when soy foods are consumed, traditional preparation methods - including the use of traditionally fermented soy products like fermented tofu, fermented miso, and fermented soy sauce - are best when it comes to our health.

At this point, no public health organization in the U.S. has recommended daily intake of soy products, including the National Cancer Institute, the American Heart Association and the American Dietetics Association. In 1995 in Japan, with all soy food products taken into account, the average intake was 50-70 total grams per day (not grams of soy protein, but of the entire food), which would translate into approximately 2 ounces per day. This is less than the amount ordinarily used in the United States with respect to a single serving of soymilk and the amount of tofu in a stir-fry. However, we've also become more and more concerned about the treatment of this food in the marketplace. Our concerns fall into three areas: (1) the growing disregard for traditional methods of preparing and consuming soy; (2) the increasing absence of whole soy foods in the marketplace; and (3) the genetic engineering of more and more soy. Here are more details we think you'll find important.

Growing Disregard for Traditional Methods of Preparing Soy

In many Asian traditions, soybeans have always undergone the processes of fermentation and aging before they have been consumed. Soy sauces, soy curds (made into tofu), soy pastes (made into miso), and other soy products like tempeh (another tofu-like version of soy) have all been traditionally produced through methods that take time and revolve around the ability of microorganisms (mostly friendly bacteria) to convert the cooked soybeans into a more digestible, nutrient-rich, and health-supportive food. We've seen studies, for example, comparing soy foods fermented with the bacterium Bifidobacterium to non-fermented soy foods. In these studies (conducted on mice), the fermented foods were able to support the skin and connective tissue of the animals (by increasing the production of a substance called hyaluronic acid) in a way that the non-fermented products were not. Two phytoestrogens (called genistein and daidzen, which we'll discuss in more detail later on in this article) were also found to be present in the fermented foods but not detectable in the non-fermented versions.

Research has clearly shown that soy proteins become more digestible with fermentation. A significant percentage of soy proteins get broken down into shorter protein strands (called polypeptides) or even into single amino acids during the process of fermentation. These protein forms require less chemical activity in our digestive tract and are much better-prepared for digestion than whole, intact proteins.

We've also seen studies that examined traditional fermentation process used to make soy sauce (shoyu), and these studies suggest that the antioxidant properties of soy sauce, and potentially cancer-preventive properties of soy sauce are both related to the process of fermentation. In addition, these studies show that the risk of allergy to soy is decreased through the process of fermentation. This conclusion makes sense to us, because many food allergies involve our immune system's response to food proteins, and the proteins in soy are clearly changed during the fermentation process.

From a manufacturing standpoint, however, the problem with traditional fermentation methods for soy is time. Proper fermenting takes time, and lengthy fermentation processes bring a cost factor into production. The vast majority of soy products in the marketplace today have not been fermented, and would be expected to lack the unique health benefits provided by soy foods prepared using traditional fermentation methods.

Absence of Whole Soy Foods

Our second concern involves the increasing number of soybean "piece parts" found in the marketplace. Unless we are eating virtually no processed soy-containing food, the soy products we're consuming are highly unlikely to bear much resemblance to naturally occurring, whole soybeans. Instead, what we will find is isolated soy protein, soy protein concentrate, textured soy protein (sometimes called textured vegetable protein or TVP), soy flakes, soy milk powders, and other extracts from the soybean that have little to do with its whole food benefits. There's been an increasing tendency in the marketplace to devalue soy for any of its unique health benefits, and to treat it instead like nothing more than a meat substitute. This approach leads to the manufacturing of soy products that are less and less comparable to traditionally fermented, whole soy foods in terms of nutrition and health benefits. Parts of the soybean are now found in literally thousands of packaged foods, along with marketing statements about the value of soy. But these isolated parts of the bean do not count as the food itself.

Genetic Engineering of Soy

Fifteen years ago, no genetically engineered food crops had been planted in the United States. Today, one of the top genetically engineered food crops is soy, and the statistics here are compelling. According to the National Agricultural Statistics Service (NASS), about 50 million acres of genetically engineered soy were planted in the U.S in 2001. By 2003, the number had risen to almost 60 million acres, and we are now close to 65 million acres and 85% of all planted soybeans.

Soybeans have not been genetically modified for nutritional reasons. They've been modified for economic reasons involving the reality of present-day agribusiness. For example, growers can now purchase "Roundup Ready" soybeans that are resistant to this glycophosphate herbicide.

There is no solid research evidence that genetic engineering of soybeans is harmful to our health, but the reason for this lack of evidence is lack of studies. Genetically engineered foods are allowed into the marketplace without studies testing their safety. There's every reason to think that our digestive tracts and our immune systems would react differently to genetically modified foods due to the abrupt presence of new proteins in these foods that would be difficult for our organ systems to evaluate. We are concerned about this type of uncontrolled experiment with a widely consumed food crop, and it's one of the reasons we support consumption of certified organic soy products. Genetic engineering is prohibited in the production of any certified organic food.

Mixed Results in the Phytoestrogen Research

In addition to these broader, generic types of concern about soy foods, we also have some specific concerns based on the most recent research with soy. First is the mixed results we've see with respect to the phytoestrogens found in soy, particularly genistein and daidzein. Most of the earlier research in this area showed consumption of these phytoestrogens to be preventive of breast cancer in women who had not yet reached the age of menopause. However, more recent research has shown that in women who are postmenopausal, these same phytoestrogens can be potentially detrimental. In addition, they can increase the rate of tumor growth in women who have already been diagnosed with estrogen-dependent breast cancer. These mixed results with respect to soy phytoestrogens and breast cancer mean that a blanket statement about the cancer-preventive effects of soy foods is no longer accurate, and that menopausal status is important when evaluating the benefits of these foods. Because the clinical issues here can be different from individual to individual, we'd recommend the advice of a healthcare practitioner for women of menopausal age considering the role of soy foods in their diet.

Goitrogens, Hemagglutinins, and Phytates

There are three other specific health issues associated with soy in the research literature on this food. The first issue involves goitrogens, substances that can interfere with thyroid metabolism and cause the thyroid to increase in size (a condition called goiter). Soybeans contain two types of known goitrogens - thiocyanates and isoflavones. For individuals with a history of thyroid problems, or at risk for such problems, we'd recommend the advice of a healthcare professional before making soy a regular part of the meal plan.

Soy also contains hemagglutinins that can sometimes increase the likelihood of our red blood cells clumping together. If that happened, our circulation could become compromised. As is the case with goitrogens, we haven't seen research showing the long-term impact of various amounts of soy foods on risk of cardiovascular disease and circulatory problems. However, fermentation, cooking, and sprouting all appear to lower the levels of hemagglutinins in soy, and we suspect that traditionally cooked and fermented soy foods are likely to pose risks only for specific individuals rather than for everyone across the board.

Soy also contains phytates that can sometimes decrease mineral absorption, including absorption of the minerals calcium, magnesium, iron and zinc. Each of these minerals has a role to play in our health. As is the case with hemagglutinins, traditional fermentation appears to significantly lower the activity of phytates found in soy. With cooking alone, there is more debate about the changes in phytate level. All of the precautions listed above are important considerations when deciding the role of soy foods in your Healthier Way of Eating.

Whole Soybeans, Traditionally Prepared Are Still a Healthy Food

It is difficult to recommend an absolute limit for individual daily consumption of soy foods because determination of this amount requires a careful look at each individual's diet and overall health status. For persons interested in finding out their optimal personal intake level, we would recommend consultation with a nutrition-oriented healthcare practitioner, such as a naturopathic physician, registered dietitian or nutritionist.

[LoveGuinness]

wow, i had no idea that there was so much involved with soy. i can totally understand now the dangers of consuming too much of it...all because its not fermented properly.

thanks for posting this josh!

[Soup Nazi]

Thanks for the heads up. :thumbup

[bellavus]

this is some excellent information regarding soy.

[Sportsmedjosh]

Remember this when your cheffing it up.

[bellavus]

Originally Posted by Sportsmedjosh

Remember this when your cheffing it up.

most defintely. I wonder if they have more information about edamame (whole baby soybeans).