Soybean Pros and Cons

While soybean products can be a healthy part of a vegetarian or traditional diet, there are several pitfalls to watch out for.  One factor is whether the soybeans are genetically modified.  Another is where they were grown (some companies who pose as organic purveyors refuse to disclose their sources).  Especially important in considering soybean pros and cons is whether the final  product was fermented or not.  This article will explain the many details of soybean products

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Soybean – Glycine max (Fabaceae)

An oilseed legume native to East Asia, soybeans have been cultivated for over 3000 years, and are  the most widely consumed legume in the world.  Soybeans contain large amounts of molybdenum, tryptophan, and manganese along with protein, iron, omega 3 fatty acids, phosphorous, copper, potassium magnesium and vitamins B12 and K.  Soybeans also contain isoflavones, antioxidants that help lower cholesterol.  Soy helps lower blood pressure, is anti-inflammatory, and has cardio protective effects. Soybeans are considered especially healthy for women because the phytoestrogens in soy help increase bone density.  However, phytoestrogens are of questionable benefit to men and may elevate unwanted estrogen.  A large percentage of soybeans in the US come from Genetically Modified seeds, so organic soybeans are recommended.  Soybeans contain goitrogens which may have negative consequences on the thyroid and may be a cause of thyroid cancer

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Fermentation is the most important factor in whether or not soybean products are healthy.  Unfermented soybean products should be avoided as they contain phytate, also known as phytic acid, a compound that robs the body of minerals.

 

Soybean products are fermented by two types of molds:

 

* Koji – Aspergillus Oryzae (Trichocomaceae)

Koji is the mold used to ferment many Japanese foods, including tamari, miso and mirin (the rice vinegar used to flavor teriyaki sauce and ponzu sauce).  Koji contains amylase, an enzyme that helps in the digestion of carbohydrates.  Koji contains the amino acid glutamate, a natural  concentrated salty flavor (known as the sixth taste or umami).

 

* Rhizopus oligosporus – Rhizopus microsporus var. oligosporus (Mucoraceae)

The mold used in the production of tempeh, Rhizopus oligosporus is edible and doesn’t produce any known toxins. Producing a white, fluffy mycelia, Rhizopus contains a natural antibiotic that inhibits dangerous bacteria including Staphyloccus aureus.  This is one reason tempeh is believed to reduce intestinal infections.  There is no record of illness resulting from the consumption of tempeh.

 

First the good news: there are three popular fermented products you can enjoy which are outlined in this section.

 

* Miso   

Miso is a fermented soybean paste originating in Japan that is becoming popular in the West.  Miso has a salty, buttery taste and can be used as a versatile condiment for a variety of recipes or as a soup base. Miso by itself is an antioxidant and is made by fermenting soybeans with the Koji mold. Miso contains vitamin K, B6, B12, calcium, iron, zinc, phosphorous, copper and is loaded with protein and amino acids.  It does contain a good amount of sodium. Those looking to stock up on quality food should store some miso paste. Twelve ounces of miso paste is enough to make several gallons of delicious soup and it is live food, not sterile the way canned soups are.

 

* Tempeh

Tempeh is made by fermenting soybeans with the Rhizopus mold.  Tempeh contains antioxidants, isoflavones and soy saponins along with fiber, complete protein and every essential amino acid.  Tempeh aids digestion and boosts the immune system while providing an easily assimilated protein in vegetarian form.

 

* Tamari ( Real Soy Sauce)

Tamari is a concentrated, fermented soy product that has been used in China for nearly 3000 years.  Tamari is rich in antioxidants and is a good source of the amino acid tryptophan.  Tamari also contains vitamin B6, iron, phosphorous, and protein.  Contrary to popular belief, soy sauce should be refrigerated after opening.

 

Now the bad news:  While risking offending proud members of the Soybean Association, this author feels the following two products should be avoided.

 

* Tofu  

Tofu is unfermented soybean curd.  Though it contains protein it is difficult for some to digest and may disrupt or interfere with normal hormones due to estrogen mimicking compounds, and compromise body mineralization.  Thus tofu has questionable health benefits.

 

* Soy Milk

There are numerous reasons to avoid soy milk besides the taste.  Since it is unfermented it also contains mineral robbing phytate and a high level of phytoestrogens.  Only two glasses of soy milk per day for one month contains enough of these hormone-like substances to change the timing of woman’s menstrual cycle.  100 gm of any soy product contains as much estrogenic content as a contraceptive pill.