Miso isoflavones

One control cycle (normal diet) then one cycle on 50 g miso/day (25 mg/day unconjugated isoflavones, n = 3)... 

Before 1990 the composition of isoflavones in soy foods was thought to be largely determined by whether the food had been fermented. Fermented foods (e.g., miso and tempeh) contain the unconjugated isoflavones agycones, while non-fermented food (e.g., tofu, soy flower, and soy milk) contain the conjugated glucoside. Subsequent experiments have demonstrated that fermentation of soy decreased the isoflavone content of the food product, but increased the urinary isoflavonoid recovery, suggesting that fermentation increases availability of isoflavones in soy (Slavin et al., 1998). 

Chiou, R.Y. and Cheng, S.L., Isoflavone transformation during soybean koji preparation and subsequent miso fermentation supplemented with ethanol and NaCl, J. Agric. Food Chem., 49, 3656, 2001. 

A study of miso found a particular rich mix of isoflavone aglycones, notably genestein and daidzdn, both known to be anticancer agents derived from their isoflavone precursors, genestin and daidzin. 

Hirota, A., Taki, S., Kawaii, S., Yano, M., Abe, N. (2000). l,l-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines. Bioscience, Biotechnology, and Biochemistry, 64, 1038-1040. 

Isoflavones (2) have usually been found as small amount phytochemicals from the legumes, grains and vegetables, and their processed foods such as traditional tofu and Indonesian tempeh which is a traditional soy product originally from Indonesia [Indonesian tempeh is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form of similar to a very firm vegetarian burger patty], miso, natto, soya milk, bean curds and bean sprouts. 

Dietary isoflavones come from traditional soy foods (SF), modem soy products (a new source of isoflavones in Western populations, e g., soy buigers, soy yoghurts), and commonly consumed foodstuffs which contain soy flour or soy protein isolates (SPI). The isoflavone content of traditional SF, e g., miso, soy milk, tofu, and modem soy products vary... 

Isoflavones, such as genistein (see Fig. 1) and daidzein, are found in Just a few botanical families, e.g., soy. Up to 3 mg/g of genistein and daidzein and their (1 glycosides are present in soybeans. Information on isofiavone content in soy products, such as soy milk, tofu, and fermented products such as miso, soy sauce, and tempeh, is given by Coward [92] and Wang [93]. 

Japanese women and women of Japanese origin living in Hawaii but who consume a diet similar to the traditional Japanese diet (rich in soy products) have a low breast cancer incidence and mortality. Women in the Far East who have low rates of breast cancer are thought to consume approximately 30-50 times more soy products than women in the United States. A case-control study in Singapore found that premenopausal women who consumed 55 g of soy per day had a 50% reduced risk of breast cancer compared to women who infrequently consumed soy foods. A high intake of miso soup has been associated with a reduced risk of breast cancer in Japanese women. In prospective trials, a trend toward an inverse association between intake of tofu and subsequent risk of breast cancer and an inverse association between intake of miso soup and development of breast cancer have been found. However, a large prospective study in Japan did not show any effect of soy consumption on breast cancer risk, although this may be because dietary intake was studied in adult women rather than in children or adolescents. A number of studies in rodents have indicated that a protective effect of a soy isoflavone-rich diet may... 

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