Soy has been deemed a healthy food for many years. After all, people of Asia have been eating soy products for 2500 years and these are the people with one of the lowest rates of heart disease and lowest incidents of breast cancer, prostate cancer and menopausal symptoms. Could it be from soy’s phytoestrogens or other soy nutrients?
Soy is the only common plant food that contains all of the essential amino acids (a complete protein) – unlike any other vegetarian protein – and because of this it has been considered an excellent substitute for animal protein (such as fish, poultry, meat and dairy). Soy can be processed and separated into Soy Protein Isolate and Soy Protein Concentrate and added to foods to enhance nutritional value. Soybean oil has no cholesterol and can be easily hydrogenated to make margarine and other vegetarian products. This is an excellent economical business opportunity for the food industry.
So with such a good, healthy profile, what’s all the fuss about? Why so much controversy on soy? How can a healthy food suddenly be considered unhealthy?
Well, first of all this is not a sudden consideration and it didn’t happen overnight. Soy has never been a health food - it was just marketed as one! Chemically speaking, it has a good nutritional profile and soy is a very inexpensive crop to grow. However, soybeans contain natural toxins, or 'anti-nutrients'. Among those toxins are enzyme inhibitors, haemagglutinin (causes red blood cells to clump together), growth inhibitors, and phytic acid. The soybean was originally considered an inedible plant that was used by farmers only to ‘fix’ nitrogen in the soil. Traditional farmers today still believe in this idea and use soybean plants in their crop rotation only to replenish nutritients in the soil.
The people of Asia knew long ago that even cooked soybeans still contained toxins and were not edible. Even though soybeans have been around for about 5000 years, they were not used for food until about 2500 years ago – when the people learned to neutralize the toxins in the soy by fermenting it. In traditional Asian diets soy is not used as a major source of protein but instead it is used in small amounts as condiment foods - and always in its fermented form. Some fermented soy products that might sound familiar are soy sauce, tempeh, miso, and natto.
In the United States it is only recent that soy has been used as a major source of protein and in such large amounts. Soy is cheap and easy to process and it proves to be an inexpensive food additive. Americans use mostly unfermented forms of soy that are processed into various foods such as vegetarian burgers, sausages, textured vegetable protein (TVP), soymilk, soy cheese, soy ice cream, soybean oil and soy flour. Soybean oil and soy flour are also added to many other foods.
The controversy with soybeans is that they can be toxic for consumption if they are not first fermented. Unfermented soy is loaded with anti-nutrients that are associated with gastric distress, poor immune system response, PMS, reproductive problems for both men and women, allergies, ADD and ADHD, increased risk of heart disease, forgetfulness, increased risk of certain cancers, malnutrition and loss of sex drive.
In Addition, Unfermented soy:
· Contains high levels of phytic acid and reduces the absorption of many minerals including calcium, magnesium, iron, copper and zinc.
· Contains enzyme inhibitors which cause digestive issues
· Contains phytoestrogens that disrupt the endocrine system and can contribute to:
o Breast cancer
o Thyroid cancer
· Inhibits the absorption of B vitamins increasing the body’s need for B12
· Increases the body’s requirement for vitamin D
· Processed soy contains high levels of aluminum which is toxic to the nervous system and kidneys
· Soy is processed at high temperature which denatures the soy proteins
· When soy protein is processed it creates the formation of toxic substances that are highly carcinogenic
· MSG is formed during soy food processing and is added to many soy foods
Fermenting soy neutralizes the toxins allowing the soybean to become a highly nutritious food which can actually help build the body’s digestive and immune systems. However, it should be duly noted that even fermented soy products should be consumed only in small to moderate amounts. Moderate consumption of fermented soy can be beneficial but large amounts of any soy product can be harmful. Keep in mind that the typical Asian diet contains about 1 ounce of fermented soy per day. Remember this when consuming soy products. The recommended fermented soy products are Miso, Tempeh, naturally fermented soy sauce and Natto.