The Secret of Soy,What is Soy Isoflavones?Function of Natural Genistein?Soy Bean Extract.

Article Content:

Introduction and Brief Benefits of Soy Isoflavones.

Soy Bean Extract INCI Name Glycine Soja Extract Soy Isoflavones Genistein Daidzein CAS 84776-91-0 Genistein CAS 446-72-0 Daidzein CAS486-66-8 photo picture image Isoflavones are polyphenolic compounds that are capable of exerting estrogen-like effects. For this reason, they are classified as phytoestrogens,compounds with estrogenic activity derived from plants. Legumes, particularly soybeans, are the richest sources of isoflavones in the human diet. In soybeans, isoflavones are present as glycosides (bound to a sugar molecule). Fermentation or digestion of soybeans or soy products results in the release of the sugar molecule from the isoflavone glycoside, leaving an isoflavone aglycone. Soy isoflavone glycosides are called genistin, daidzin, and glycitin, while the aglycones are called genistein, daidzein, and glycitein, respectively (chemical structures of isoflavone aglycones). Unless otherwise indicated, quantities of isoflavones specified in this article refer to aglycones,not glycosides.

Introduction and Brief Benefits of Soy Isoflavones:

Soy Isoflavones are derived from Soybeans. Isoflavones belong to a class of compounds known as flavonoids. The highest amounts of Isoflavones can be found in soy nuts and tempeh. Isoflavones are fairly stable; they are not destroyed under normal cooking methods. Soy Isoflavones is a promising nutraceutical with potentially significant health benefits.

Benefits of using Soy Isoflavones:

Soy isoflavones provide beneficial effects for the prevention and treatment of breast, colon and prostate cancers.
Soy isoflavones are also known as phytoestrogens (plant estrogens), signifying their mild estrogenic activity.
Soy isoflavones reduce the bioavailability of sex hormones that may stimulate tumor growth capacity in both men and women.
Soy isoflavones are beneficial in preventing osteoporosis and autoimmune conditions.
Special soy isoflavones supplements are also available in capsules and tablets. Some provide added digestive enzymes.
Soy Bean Extract INCI Name Glycine Soja Extract Soy Isoflavones Genistein Daidzein CAS 84776-91-0 Genistein CAS 446-72-0 Daidzein CAS486-66-8 photo picture image

Properties of Isoflavones:

Phyto-estrogens are dietary nonsteroidal plant compounds of diverse structure that produce estrogenic responses. They vary greatly in both their potency and physiological effects. There are three main classes of phyto-estrogens: isoflavones, coumestans and lignans, which are present in either plants or their seeds. Isoflavones in four chemical forms: the aglycons daidzein, genistein and glycitein; the glucosides daidzin, genistin and glycitin; the acetyiglucosides and the malonylglucosides. Isoflavones are structurally similar to the mammalian estrogen, estradiol. The principal compounds within these classes of phyto-estrogens have been shown to have weak estrogenic activity, ranging from 0.002 to 0.001 the activity of estradiol. Their effect can both be agonistic and antagonistic to 17-Beta estradiol when they act simultaneously at target tissues. Antagonistic compounds normally compete for 17-Beta estradiol receptors but fail to exert a similar estrogenic effect.

Health Effects of Isoflavones:

The above raises the interest in isoflavones as protective agent for hormone-related diseases, as menopause, osteoporosis and coronary heart disease and breast cancer.Research in several areas of healthcare has shown that consumption of isoflavones may play a role in lowering risk for disease. They can fight disease on several fronts. The following potential health benefits are attributed to isoflavones:
Soy Bean Extract INCI Name Glycine Soja Extract Soy Isoflavones Genistein Daidzein CAS 84776-91-0 Genistein CAS 446-72-0 Daidzein CAS486-66-8 photo picture image

Ease menopause symptoms:

The hot flush is the most common and disruptive symptom of the menopause. Estrogen replacement therapy eliminates 60% of flushes within three months. Hormone replacement generally alleviates the condition, as well as the vaginitis occurring at the menopause due to atrophy. However, due to increasingly suggested and reported negative side effect of hormone replacement therapies, women today request dietary and natural' options for symptom management. The rarity of the problem in soy consuming countries has prompted some investigations to determine whether phyto-estrogens have a similar effect. Human studies have shown that soy isoflavone supplementation resulted in significant reduction in the frequency and intensity of hot flushes and increases serum levels of SHBG, which in turn may alleviate symptoms such as hot flushes and vaginal dryness.

Recent studies have found that soy isoflavones can reduce menopause symptoms such as hot flushes and increase bone density in women. Indeed, many menopausal and post-menopausal health problems may result from a lack of isoflavones in the typical Western diet. Although study results are not entirely consistent, isoflavones from soy or red clover may be helpful for symptoms of menopause. A study carried out by "Health Test" in 2004 investigated the prescription behaviour of 27 doctors for women with menopause symptoms. It showed that isoflavones were recommended twice (44%) as often as hormonal treatment (22%). The prescribed supplements were mainly based on the following plants: soy, black cohosh and hops.

Isoflavones improve bone health:Soy and Osteoporosis:

Soy Isoflavones help in the preservation of the bone substance and fight osteoporosis. This is the reason why people in China very rarely have osteoporosis, despite their low consumption of dairy products, whereas in Europe and North America the contrary happens. Unlike estrogen, which helps prevent the destruction of bone, evidence suggests that isoflavones may also assist in creating new bone. Other studies are not entirely consistent, but evidence suggests that genistein and other soy isoflavones can help prevent osteoporosis.

Osteoporosis in women is particularly associated with menopause, since the loss of estrogen accelerates bone loss. The hormonal effect of phyto-estrogens, coupled with the comparative rarity of the disease in populations consuming soy, has also prompted investigation of their effects on osteoporosis. Dietary effects have been investigated for achieving peak bone mass and preventing bone loss in later life. It has even been showed that isoflavones do not only prevent the loss of bone, but even allow significant increases in both mineral content and bone mineral density in the lumbar spine region. Similar trends were notes for other skeletal areas. An important role in this effect is ascribed to daidzein. More human studies are currently conducted.

Many soy foods are naturally high in calcium as this mineral is added as a coagulating agent. In addition, soy also contains magnesium and boron, which are important in bone health.

In addition, isoflavones in soy foods may inhibit the breakdown of bones. Daidzein, a type of isoflavone, is actually very similar to the drug ipriflavone, which is used throughout Europe and Asia to treat osteoporosis.

A study completed by Erdman in the early 1990's inspired the many studies that followed to investigate the possible benefits of soy on bone health. Erdman's study focused on post-menopausal women who consumed 40 g of isolated soy protein daily for 6 months. Erdman found that these women had significantly increased bone mineral density as compared to the controls.

A recent study published in 2003 by the Oklahoma State University showed that soy protein was more effective in bone formation and retention of calcium inside the body (excreting less calcium in urine) compared to milk protein. In addition, researchers also found that the benefits of soy on bone health were more pronounced in postmenopausal women who were not on hormone replacement therapy.

There is no doubt that soy has a role in maintaining healthy bones and may even help to prevent bone loss in postmenopausal women. However, it is still not clear whether the benefits are due to its soy protein, or its isoflavones daidzein and genistein, or the combination of them. The best approach is to include soy foods such as tofu, tempeh, soy milk, edamame etc in your diet instead of taking isolated soy supplements. Many brands of soy milk are now fortified with calcium. Hence, one glass of fortified soy milk provides an equivalent amount of calcium from a glass of cow's milk.With the increasing public concerns regarding genetically modified foods, look for soy products which use non-genetically modified soy crops in their production.
Soy Bean Extract INCI Name Glycine Soja Extract Soy Isoflavones Genistein Daidzein CAS 84776-91-0 Genistein CAS 446-72-0 Daidzein CAS486-66-8 photo picture image

Cancer/Immune Function:

High soy consumption leading to high exposures of soy isoflavones has been associated with a reduced risk of cancers at many sites. Several studies on experimental animals and cell cultures have demonstrated cancer chemo-preventive effects of soy isoflavones. In addition to weak estrogenic activities, isoflavones possess a variety of characteristics such as antioxidant, anti-proliferative and differentiation-inducing abilities. A recent study shows that isoflavones might also increase the metabolism of endogenous estrogens to the protective 2-hydroxylated estrogens in women, and this may play an important role in lowering 1 7Beta-estradiol levels and the long-term risk for breast cancer. Also the role of the immune function has become increasingly important in our understanding of the mechanisms underlying the body's ability to prevent cancer. At high doses, especially daidzein was shown to enhance several immuno-regulatory functions.

Isoflavones seem to be protect agains tumors because thet act against cancer cells in a way similar to many common cancer-treating drugs. Population-based studies show a strong association between consumption of isoflavones and a reduced risk of breast and endometrial cancer. Women who ate the most soy products and other foods rich in isoflavones reduced their risk of endometrial cancer by 54%.

Bio-activity:

Diet derived health protectants, like the isoflavones, need sufficient systemic bio-availability to exert the beneficial effects. Determinants of isoflavone bio-activity are structural differences between the isoflavones, gut micro-floral metabolism and mammalian phase-II metabolism. Gut micro-floral influences seems a major factor in inter-individual variation in isoflavones blo-availability. Individuals who excrete larger amounts of faecal isoflavones have much higher urinary and plasma isoflavone levels than individuals who excrete small amounts of isoflavones in faeces. Moreover, these high excreters experience more prolonged plasma diadzein and genistein. Research has shown that glycitein and daidzein are more blo-available than genistein. Urinary recovery of glycitein and daidzein was about 47% and 52% respectively after a single soy dose, whereas the recovery of genistein was 37%. Genistein's lower bio-availability may be due to its more rapid degradation in the gut compared with daidzein and glycitein.
Soy Bean Extract INCI Name Glycine Soja Extract Soy Isoflavones Genistein Daidzein CAS 84776-91-0 Genistein CAS 446-72-0 Daidzein CAS486-66-8 photo picture image

Protect against prostate problems:

Isoflavones may be benificial for men's health because they may protect against enlargement of the male prostate gland. Studies show isoflavones slowed prostate cancer growth and caused prostate cancer cells to die. Isoflavones act against cancer cells in a way similar to many common cancer-treating drugs.

Isoflavones are natural plant hormones:

Isoflavones can be found in many foods but the best known source is the soy bean (Glycine max). The soy isoflavones are responsible for most of the soy health benefits. The Soy bean is a plant cultivated as foodstuff whose health properties have recently been discovered. Thorough studies have revealed that the consumption of the soy beans have favourable effects on people's health. Another source of isoflavones is red clover. As opposed to soy beans, red clover is normally not eaten but the isoflavones are extracted in industrial processes and used to make isoflavones supplements.

Isoflavones are natural antioxidants:

A recent study has demonstrated that isoflavones have potent antioxidant properties, comparable to that of the well known antioxidant vitamin E. The antioxidant powers of isoflavones can reduce the long-term risk of cancer by preventing free radical damage to DNA. Genistein is the most potent antioxidant among the soy isoflavones, followed by daidzein.

Soy infant formula:

Research on infant formula made with soy is beyond the scope of this article. I'd like to point out, however, that infant formula with soy has been around since the 1960's and fed to babies who were not breastfed and who were allergic to cow's milk. Soy allergies appear to be much less common than allergies to cow's milk, and fewer than 10% of infants allergic to cow milk are also allergic to soy formula. As of today, there would appear to be no obvious detrimental effect, but formulas are constantly changing and research is ongoing into the effects on children's thyroid, sexual, immune and intestinal health.

Soy and heart disease:

Soy isoflavones also appear to reduce cardiovascular disease risk via several distinct mechanisms. Isoflavones inhibit the growth of cells that form artery clogging plaque. These arteries usually form blood clots which can lead to a heart attack. A review of 38 controlled studies on soy and heart disease concluded that soy is definitely effective for improving cholesterol profile. There is some evidence that isoflavones are the active ingredients in soy responsible for improving cholesterol profile.

Early Eastern texts prescribed soy as good for digestion, detoxification, and basic good health and well being.These data were then extrapolated into an assumption that soy had almost magical abilities and the "miracle" of soy blossomed in the 1990's. Advocates claimed it was the answer to all kinds of ills, from high cholesterol to low bone density to cancer, but failed to underscore the fact that a traditional Eastern diet uses much less processed soy than many Westernized soy products.In 1999, the FDA allowed soy food manufacturers to advertise the health claim that 25 grams of soy protein a day could reduce bad cholesterol (LDL) levels. (It should be noted that this claim did not extend to isolated isoflavones.) A backlash of research then came out purporting that soy was a dangerous allergen, created thyroid problems and caused cancer.

However, a well-balanced August 2005 report from the Agency for Healthcare Research and Quality reviewed hundreds of studies with support from the National Institute of Health. In the 68 studies examining the impact of soy on cholesterol levels, they found that it did indeed reduce LDL and triglyceride levels. They found insufficient data among 200 human studies to suggest that soy had an effect~ negative or positive~on bone health, cancer, kidney disease, endocrine function, reproductive health, neurocognitive function, or glucose metabolism. They hinted that soy isoflavones may protect against fractures after menopause.

Coronary Heart Disease (CHD) The importance of lowering serum cholesterol in reducing the risk of CHD, and total mortality, is now well established.As CHD is a multi-factorial disease, many dietary factors are involved in affecting risk. LDL-lipoproteins are normally taken up by the liver, thus maintaining levels of serum cholesterol, but if they are oxidatively damaged they are taken up by macrophages to form foam cells in the lining of arteries, initiating the first stages of atherosclerosis. In soy, the positive role of soy proteins is strongly recognised. The Food and Drug Administration in the US has approved a health claim for cholesterol lowering effect when consuming 25g of soy protein per day. The isoflavones may prevent oxidative damage through their antioxidant activities, and are believed to support an improved HDL/LDL ratio. Furthermore because of its effects on tyrosine kinases, genistein may have a role in suppression of the cellular processes which lead to atherosclerosis.