Frequently Asked Questions

All questions are reviewed and answered by our specialist,
Dr Michiel Smit (PhD, Soybean physiology)

While researching soybeans as crop physiologist for more than 30 years I have increasingly come to the realisation that it was “created for mankind”.

  • It has the highest protein (essential for life) yield per unit area of all agricultural products (and fixes its own nitrogen to make that protein!);
  • it has a complete protein (PDCAAS = 1) containing all the essential amino acids in the right ratio for human requirements; it is the only legume that provides ample amounts of the essential omega-3 fatty acid alpha-linolenic acid; and
  • it is loaded with phyto-nutrients.

Many of the so-called anti-nutritional factors that soya have been accused of in the western world, have in my lifetime been scientifically proven to actually contain health benefits. The stark contrast in health risks between the Western compared to the traditional Oriental people is a silent testimony to the merits of a plant-based life style which includes the humble soybean.

It has been cultured and consumed in that part of the world for thousands of years and the benefits of the oriental lifestyle which includes regular consumption of “Edamame” is significant.

Two books that I highly recommend to get perspective on the health benefits of soybeans and to compare the life style and associated risks between the West and Far East would be:

  • “The simple soya and your health” by Dr. Mark Messina, Dr. Virginia Messina & Kennith Setchell; and
  • “The China Story” by Prof. TC Campbell.

Question: There is a lot of talk about phyto-oestrogen and the perceived risk it may pose to those eating soya?

Answer: The current knowledge on the risk of breast cancer in adult women and the effect of soybean consumption is well summarised in the Cornell University Fact Sheet #10, March 1998, updated July 2002:-

“Estrogen is a hormone that is necessary for the normal development and growth of the breasts and organs important for childbearing. It helps control a woman's menstrual cycles and is essential for reproduction. Estrogen also helps maintain the heart and healthy bones. However, a woman's risk for breast cancer is associated with lifetime exposure to estrogen. A diet rich in phytoestrogens (SOYBEANS) has been proposed as a way to decrease breast cancer risk.

Why is this so?

Most phytoestrogens are not stored in the body, but are quickly broken down. Phytoestrogens are weak estrogens, and may prevent stronger human estrogens from binding to the estrogen receptor. If the weaker estrogens bind to the receptor instead of the stronger ones, there may be less breast cell division. Women with diets rich in phytoestrogens also excrete more estrogens into their urine, and have lower blood estrogen levels. Some studies have shown that women with a diet rich in phytoestrogens have longer, and hence fewer, menstrual cycles. All of these factors may contribute to reduced breast cancer risk”. Regular consumption of soya can also help ease the menopause phenomena. In the most comprehensive study to date to examine the effects of soy on menopause, researchers who published in Menopause: The Journal of the North American Menopause Association found that two daily servings of soy can reduce the frequency and severity of hot flashes by up to 26 percent, compared to a placebo. The research stems from observational evidence in Japan, where researchers have found the low frequency of hot flashes in Japanese women might be attributed to the high soy consumption that often begins in utero and continues throughout their lifespan.

It is therefore incorrect to state that phyto-oestrogen “promote breast cancer in adult women”. It is equally incorrect to suggest that soybeans have the potential to grow breasts in boys”.

Research published in Fert Steril 2010 May 1;93(7):2095-104 concludes that phyto estrogen do not exert feminizing effects on men at intake levels equal to and even considerably higher than are typical for Asian males.

Question: GM Foods are the way forward, why all the trouble to keep your Edamame non-GM?

Answer: We believe the public should have the freedom of choice and be able to find non-GM products if they so chose. The non-GM soya we grow is still as the “Master Mind” designed it and as the Oriental people cultivated and maintained it for centuries. A second reason is that there are still very real concerns about GM foods and the evidence published in credible scientific journals is mounting (see for example the article in Int J Biol Sci 2009; 5(7):706-726, published in a journal with high impact factor).

Question: What is the difference between the vegetable type soybean (Edamame) and the commercial soybean currently grown in South Africa?

Answer: Edamame (a Japanese word for “beans on a stork”) is, amongst others, sweeter and was selected and cultivated for human consumption in the Far East over a period of centuries. When it was brought over to the Western world it was bred, selected and cultivated primarily for animal feed. Gradually chemical and physical differences developed that is very obvious should you compare the two types today. In the USA less than 1% of the soya produced is used for human consumption and in South Africa it is about 7%. The vegetable type soya was not produced in South Africa until the eThekwini City Council started the Edamame Development Programme in 2011.

Question: Mature soybeans contain trypsin inhibitor. Is that poisonous and how can soybeans be healthy if it contains trypsin inhibitor?

Answer: Trypsin inhibitor is NOT a poison! It is nature’s way of protecting the mature seed from insects until the next summer and growing season. Trypsin inhibitor (TI) increases gradually during the maturation process (is not present in green vegetable type soya) and makes the protein unavailable for growth. Insects know that and will therefore not eat mature soybean. The Edamame soybeans have been selected in the Far East to have much lower levels of TI in the mature seed and should therefore be protected from insects much like peanuts and sugar bean. The TI in soybean is heat susceptible and will break down when the soybean is cooked for a couple of minutes.