Human health & isoflavon
C an c e r	In America, one out of every three people will develop cancer in their lifetime.  However, rate of individual cancers vary, and diet may be the factor contribute to this variation.  To reduce fat intake and to increase fruit, vegetables, and fiber intake is always encouraged.  In the past three to four years, researchers have pay more attention on the study of soybean.  The reason of this attention is that soy products play a role in lowering risk of cancer, osteoporosis, heart disease, and relief of menopause symptoms.  The five different chemical classes of anticarcinogens in soyeans- phytosterol, phytates, saponins, protease inhibitors and isoflavon are the main reason of the positive health effect.  Amount the five soybean anticarcinogens, isoflavon, a dietary source of group of phytochemical, has received the most focuses during the past five years.
i soflavone- a ntiestrogen & b rest cancer	Based on the information from United Soybean Board, isoflavone are weak estrogen, possessing between 1/1000 and 1/100,000 the activity of estradiol.  Weak estrogens may function as antiestrogen because they can compete with endogenous estrogen for binding to estrogen receptors.  In doing so, they block the more potent endogenous estrogen from exerting their effect.  A recent news about one such isoflavone, raloxifene, which has been shown to improve bone health without exerting as estrogenic effect on the endometrium (U.S. News & World Report: March 02, 1998).  Since high blood levels of estrogen are an established risk factor for breast cancer, weak estrogens have been postulated as being protective against this form of cancer.  We can test this result by looking at Japanese breast cancer mortality rate which is one-fourth of the U.S.
g enistein & tyrosine protein k inase	Two primary isoflavones in soybeans are genistein and daidzein.  In 1987, Japanese researchers isolated an isoflavone compound genistein from fermentation broth of Pseudomonas sp (see credit).  In their study, they show that genistein is a highly specific inhibitor for tyrosine kinases.  Tyrosine protein kinase (TPK) activity is known to be associated with oncogene products of the retroviral src gene family.  The kinase activity is strongly correlated with the ability of retroviruses to transform cells and is also associated with the cellular receptors for several growth factorys such as insulin and epidermal growth factor.  The results of these characteristics of TPK suggest that TPK play an improtant role for cell proliferation and cell transformation.  Because of the role of TPK in controlling cell growth, agents that inhibit TPK activity are considered to be potential anticarcinogens.  In their study is the genistein.  There are more than 100 studies have found that in vitro, genistein inhibits the growth of cancer cells including breast, colon, lung, leukemia and prostate cells.
Heart D isease	Systemic arterial compliance is a measure of the elasticity of the main circular arteries and is an independent risk factor for heart disease.  An Australian study of perimenopausal and postmenopausal women found isoflavone ingestion (80 mg/day) improved systemic arterial compliance by 26 percent.  Soybean isoflavone may help to reduce heart disease risk (The Ohio Soybean Council).
M enopau se	One synptom experienced by women going through the menopause is hot flashes.  Researchers has found that the weak estrogenic effects of isoflavones will help to relive menopause symptom.  The Italian researchers fed two group of postmenopause women either 60 gram of casein protein or a similar amount of soy protein.  After 12 weeks of observation, the hot flashes symptom decreased by 45 percent in soy group and 30 percent in casein group (The Ohio Soybean Council).
O steoporosis	Bones have the ability to remodel constantly.  There are about 7000 mg of calcium exit and enter the bones every day.  To retain the amount of calcium by the body is improtant.  There are factor cause urinary calcium loss such as protein.  However, soy protein causes less calcium to be excreted through the urine (United Soybean Board).  Soybean Isoflavones help to inhibit bone resorption directly.  Incorporating soyfoods into the diet is one easy way to help reduce risk of developing osteoporosis.
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