The propaganda that has created the soy sales miracle is all the more remarkable because, only a few decades ago, the soybean was considered unfit to eat – even in Asia. The soybean did not serve as a food until the discovery of fermentation techniques, sometime during the Chou Dynasty (1134bc to 246 bc). The first soy foods were fermented products like tempeh, natto, miso and soy sauce.
The Chinese did not eat unfermented soybeans as they did other legumes such as lentils because the soybean contains large quantities of natural toxins or “antinutrients”. First among them are potent enzyme inhibitors that block the action of trypsin and other enzymes needed for protein digestion.
These inhibitors can produce serious gastric distress, reduced protein digestion and chronic deficiencies in amino acid uptake. In test animals, diets high in trypsin inhibitors cause enlargement and pathological conditions of the pancreas, including cancer.
SOY ALSO CONTAINS SUBSTANCES THAT DEPRESS THYROID FUNCTION. A very large percentage of soy is genetically modified and it has one of the highest percentages contamination by pesticides of any of our foods.
Soybeans are high in phytic acid (phytates), present in the bran or hulls of all seeds. It’s a substance that can block the uptake of essential minerals – calcium, magnesium, copper, iron and especially zinc – in the intestinal tract.
The soybean has one of the highest phytate levels of any grain or legume that has been studied, and the phytates in soy are highly resistant to normal phytate-reducing techniques such as long, slow cooking.
When precipitated soy products like tofu are consumed with meat, the mineral-blocking effects of the phytates are reduced.
People who consume tofu and bean curd as a substitute for meat and dairy products risk severe mineral deficiencies. The results of calcium, magnesium and iron deficiency are well known; those of zinc are less so.
SOY AND CANCER The new FDA ruling does not allow any claims about cancer prevention on food packages, but that has not restrained the industry and its marketers from making them in their promotional literature.
“In addition to protecting the heart,” says a vitamin company brochure, “soy has demonstrated powerful anticancer benefits…the Japanese, who eat 30 times as much soy as North Americans, have a lower incidence of cancers of the breast, uterus and prostate.”
Indeed they do. Nevertheless, the Japanese, and Asians in general, have much higher rates of other types of cancer, particularly cancer of the esophagus, stomach, pancreas and liver. Asians throughout the world also have high rates of thyroid cancer. The logic that links low rates of reproductive cancers to soy consumption requires attribution of high rates of thyroid and digestive cancers to the same foods, particularly as soy causes these types of cancers in laboratory rats.