History of Fermented Soy and Health

Humans have been consuming fermented foods for more than 10,000 years. Fermentation is the oldest known form of food biotechnology and provides a means for producing safe and well preserved foods. Records of barley conversion to beer date back more than 5,000 years. The traditional fermentation process serves several functions, including the enrichment of food substrates biologically with protein, essential amino acids, essential fatty acids, vitamins, polyamines, carbohydrates, and numerous anti-oxidants and phytosterols, and increases the quantity, availability, digestibility and assimilation of nutrients in the body.

In Asia, where soy has been a dietary staple for thousands of years, the traditional fermented soy foods are considered to have more health promoting benefits than the super-processed soy products that are consumed in the West. This is due to its broader nutrient profile and high bioavailability. It is believed that the inclusion of a moderate amount of fermented soy products in the traditional diet of Asian populations play an important role in overall disease prevention and enhancement of well-being. On the other hand, consumption of soy products in the United States and Western Europe has been a relatively new phenomenon and limited to the 20th century. For example, the average intake of soy protein in Southeast Asia ranges from 10-50g per day in contrast to 1-3g per day consumed by Americans (Barnes et al., 1995).  

The fermentation process in soy removes trypsin inhibitors found on the coating of soy that interfere with the absorption of nutritive compounds. It is increasingly recognized that cultured soy products such as miso, natto, tempeh, fermented bean curd, soy sauces, fermented soy milk and beverages have enhanced nutritive bioavailability and reducie the risks of certain types of cancers while promoting heart and bone health, and alleviating menopausal symptoms. Fermenting or culturing soy has also been shown to enhance the bioavailability of iron and copper and to render these nutrients in their most beneficial forms. These products should not be confused with uncultured soy such as tofu, soymilk, soynuts, etc and soy protein isolates which have potentially anti-nutritive value due to their high phytic and oxalic acid levels, and can block the absorption of vital nutrients such as calcium.

The fermentation process is also thought to convert the isoflavone precursors genistin and daidzin to their active anti-cancer isoflavone forms, genistein, and daidzein. It is unfortunate that in the Untied States health conscious consumers, especially women concerned about developing breast cancer, are urged by media and consumer reports to consume soy or soy protein isolates which are not the way in which soy is traditionally consumed in Japan. The overwhelming majority of soy consumed in Asian countries, such as Japan, China, Korea, and Indonesia is in its cultured or probiotic form enhanced with genistein and daidzein . Japanese researchers found that the cultured broth of Saccharomyces cerevisiae or Brewer’s Yeast, produced both in vivo and in-vitro experiements, bio-antimutagenic and anticlastogenic activity with mutagen formation reduced by 47% just by the administration of the cultured broth. A study of the culturing method involved in the production of the Japanese traditional food, miso, concluded that the cultured soy medium had thus produced its own unique anti-carcinogenic activity by strongly inhibiting formation of cellular mutations. 

Stenotrophomonas maltophilia, used to ferment the soy in JIVA™, contains a high percentage of branched-chain fatty acids (c.f., U.S. Pat. No.7,070,965). Other bacterial genera containing high percentage branched-chain fatty acids are: Xanthomonas, Flavobacterium, Capnocytophga, Altermonas, Cytooophage, Bacillus, Chryseobacterium, Empdobacter, Aurebacterium Sphinggobaacterium, Staphylococcus, Azobacter and Pseudomonas. These bacteria, and others that may contain a high percentage of branched chain fatty acids, are microorganisms that may be considered for fermentation of soybeans. For example, Azotobacter vinelandii is a diazotroph described in U.S. Patent 4,877,739 that can fix nitrogen while grown aerobically. It is a genetically tractable system that is used to study nitrogen fixation. These bacteria are easily cultured and grown. It is a free-living N2 fixer which is known to produce many phytohormones and vitamins in the soil ( Order Pseudomonadles).

The World Health Organization reported in 2000 that the Japanese with their extensive consumption of cultured soy products, such as miso and natto, together with accompanying food like ginger, ocean herbs, and green tea, have the longest and “healthiest life expectancy” of any other people on Earth. Americans on the other hand do not even appear on the top 20 of the WHO list of life expectancy. The Western diet has undue emphasis on the consumption of “smart” products that are processed or genetically modified. 

Unfortunately, the abandonment by consumers in developing countries of their more traditional fermented foods in exchange for the “sophisticated” Western dietary products could have serious consequences. For example, the replacement of indigenous fermented cereal drinks with cola beverages that have empty calories could have a serious impact on the daily nutrition of many of these consumers in developing countries when the extensive medical benefits of consuming the traditional sources of probiotic whole-food nutrition is lost .

A Japanese study found that the level of genistein, a chemopreventive agent, in the fermented soybean products was higher than in soybeans and soybean products such as soymilk and tofu. This study along with others have postulated that the beta -glycosyl bond of genistin is cleaved to produce genistein by microbes during fermentation to yield miso and natto. On the basis of these data for average annual consumption of soybeans and related products, daily intake of genistein and genistin by the Japanese was calculated to be 1.5-4.1 and 6.3 -8.3 mg/person, respectively. These levels are much higher than those of Americans or Western Europeans, whose mortality rates for breast, colon, and prostate cancers are greater than the Japanese.  

Conclusion There is now considerable evidence for a variety of health benefits associated with consuming cultured whole soy protein. Although researchers have not always been able to identify all of the responsible components in soy, epidemiological data and both in-vitro and in vivo studies provide evidence that the benefits of consuming specially fermented soy protein inhibits not only certain types of cancer as well as cardiovascular disease, and alleviates menopausal symptoms and osteoporosis.

Read the clinical studies on the use of Fermented Soy
 

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