Native to China, soybeans have for thousand of years have been called "the meat of the earth". The cultivation of soybeans is recorded as early as 2800BC. From China, use of the bean spread to Japan and Korea. Soybeans were taken to Europe in 1712 by a German botanist. By 1969 the American government had subsided over 41 million acres for soybean cultivation and now America leads with China in commercial soybean products.

PHYTO-ESTROGENS

The chemical composition of the soybean is about 34% protein, 18% oil and 33% carbohydrates, plus minerals and potassium and vitamins. Soybeans are low in saturated fat and cholesterol free. As a rich plant source in linolenic acid (an omega 3 fatty acid) and phytoestrogens (plant estrogens), soy is being studied for its health properties, especially the role of soyfoods in preventing and perhaps treating osteoporosis, heart disease, cancer kidney disease and the effects of soy on the menstrual cycle. It is contended that these phyto-estrogens which consist of compounds such as isoflavines and lignans are at least part of the reason why Asian people and vegetarians have a low rate of heart disease and cancer (Knight & Eden).

Phyto-estrogens are found in cereals, legumes and grasses. Isoflavones are generally restricted to legumes with the highest concentration found in soy beans and in soy products. Linans are found in almost all cereals and vegetables with the highest concentration especially in linseeds (flaxseeds).

The story of soy is so far very positive (See table 1). However remember that more is not necessarily better! Soy foods should be consumed as part of a well balanced diet of wholegrains, land and sea vegetables. Some toxic reactions to and toxic substances in beans have been identified scientifically and these are "trypsin inhibition, cyanogenetic glucosides, saponins, alkaloids, goitregenic factors hemagglutinins" (Muamnoto). These can be used for some medical purposes but is not recommended to eat large amounts of beans for a long period of time. To remove toxins, beans must be cooked well for a long time or roasted before cooking. The trypsin inhibitors and heamagglutin, which have been labeled as growth-suppressing, appear to be mostly destroyed by fermentation.

Cooking with beans together with sea vegetables is essential. The traditional Japanese diet uses tofu and other soy foods in small amounts, together with sea vegetables such as Arame, Wakame, Kombu and Agar. Considering that soybeans contain a thyroid-depressing element, sea vegetables, rich in iodine, a mineral required for proper thyroid function, counterbalance that effect. It is for this reason sea vegetables such as Kombu and also barley grain are used to produce good quality soy beverages. Research at the universities of Illinois and Kansas has shown that soybeans may interfere with absorption of zinc (Judy Brown). This is probably why folklore has it that soyfoods can lower sexual energy. Once again it is extremely important to eat soy as part of a wholegrain diet with a variety of vegetables from the land and sea.

FERMENTED SOYFOODS
The fermentation of soyfoods renders them highly nutritious supply of essential amino acids and many vitamins and minerals. Most of the Vitamin B originally present in beans is lost in the cooking process, but fermented beans contain more. In Asian countries it is rare to eat the soybean just simply cooked, it is almost always eaten after it has undergone some fermentation process as with Miso, Natto, Tempeh, Tamari and Shoyu (Japanese Soy Sauce). Through microbial action the fermentation process serves to break down the protein into its component amino acids.

Fermented soyfoods contain protein, vitamins and anti-carginogenic substances (isoflavone agylcones) but do require to be consumed with wholegrains such as brown rice to enable more complete nutrition. "However, in non-fermented soy products such as tofu and soymilk these isoflavones are present in an altered form as beta glycoside conjugates which have no anti-carcinogenic effect" (L Coward).

Even though fermented foods appeal for their alkalising and digestive qualities plus it seems possible that fermented foods such as miso, pickles and sourdough breads could help our own intestinal bacteria synthesis B12, more is, again not necessarily better! Too much fermented food could cause some problems. "An excess of Miso may result in backaches, water retention and a short temper…In addition fermented foods, as well as yeasted breads or cakes, are not recommended for those with either systemic or localised yeast infections. The right amount of fermented foods on the other hand will aid in the digestion of the rest of the meal, especially when it is high in protein fats or grain" (Anne Marie Colbin). Fermentation does increase nutritional richness: the bacteria

synthesis additional enzymes and vitamins and create a more digestible amino acid balance. As with everything moderation is the key to attaining the nutritious benefits of fermented soyfoods.

SOYMILK is very popular for those on dairy-free and cholesterol-reduced diets. There are many brands but look out for those made with whole soybeans and no artificial additives and preservatives. (Remember to cook soy beans together with the sea vegetable Kombu and barley ads already mentioned)

Soy protein Isolates are a highly processed refined product of soybeans where the natural oils are extracted and vitamins and minerals reduced. The trypsin-inhibitor content of soy protein isolate is high and the phytate content is also high. "Phytates block the uptake of essential minerals, calcium, magnesium, iron and especially zinc-in the intestinal tract. Phytates found in soy products interfere with zinc absorption…only a long period of fermentation will significantly reduce the phytate content of soybeans". (JG Hattersley). It appears that sea vegetables which are high in minerals are necessary in a diet based on wholegrains and vegetables (High in phytates).

Tofu is made by extracting the protein from soybeans and combining it with Nigari, a natural coagulant made from seawater. "Although tofu is high in protein, it is not a wholefood. It contains 28% less iron. only 10%, of the fibre and B vitamins. and none of the Vitamins A arid C found in cooked whole soybean's -  the "wholefood" (Anne Marie Colbin). Therefore, once again. it is important to eat in small quantities with mostly wholegrains and a variety of vegetables. Tofu can even be a wonderful remedy for reducing fevers - just apply it to the forehead and the back of the neck.  

Tempeh is a fermented soyfood, very popular in Indonesia. It is produced by a natural culture of soybeans in a similar process to that by which cheese and yoghurt are made. It is high in protein, low in saturated fats and contains lecithin which is important for the nervous system, and essential poly-unsaturates which distribute the fat soluble vitamins around the bloodstream and supply energy. The 'rhizopus' mold used in tempeh fermentation produces natural antibiotic agents which are thought to increase the body's resistance to intestinal infection.

Miso is a naturally fermented food made from cooked soybeans and either cooked white rice, barley, brown rice, sweet young rice or made front whole soybeans that has been impregnated with the Aspergillus oryzae organism (koji). Not only is it a "vegetarian yoghurt", high in protein, including all the essential amino acids B vitamins and calcium, but it is free of toxins, while the enzymes arid bacteria in it assist proper digestion.

Shoyu is a traditional soy sauce from Japan. Shoyu has no artificial additives, flavouring or preservatives. It is made from whole soybeans with a small amount or wheat and incubated with the koji mould. "Shoyu stimulates the secretion of digestive fluids in the stomach, has a preservative effect on food and fosters the growth of healthy bacterial cultures in the intestinal tract. Further, it improves circulation and strengthens the contractions of the heart and often completes the protein balance of foods since it includes the amino acids, usually lacking in cereal grain" (Alarcea Weber). It is therefore preferable to add to wholefoods such as rice.

The research and findings show that a diet which includes soy in combination with whole grains, land and sea vegetables lower the risk of cancer and heart disease. "The incidence of breast,  colon, endometrial cancer are lower in Asia and Eastern Europe than Western countries. Dietary influenced have been identified as major determinants of risk in stomach and lung cancers... Vegetarians and those consuming a macrobiotic diet also have a lower risk of cancer and heart disease" (Knight & Eden).

What better way to Finish a "Soyfood Story" than with recipes?

EASY MISO SOUP WITH WHOLEGRAIN RICE  
(serves 4)

Wakame -  7cm strips
Onions -  1 cup
Filtered Water -  5 cups
Miso  -  2 TBS
Cooked Brown Rice - 1-2 cups
Spring Onions, parsley, ginger or watercress.  

Menopause: Phyto-estrogens in soy have been proposed as the reason why Japanese women are much less likely to suffer with menopausal symptoms.

An Australian study reported by Murkes, Lombard & Strauss also showed that women consuming soy had an approximate 40% reduction in menopause symptoms, such as hot flushes. More studies are being conducted.

Soy Glossary

ISOFLAVONE a plant based estrogen (also called phytoestrogen) that interupts the function of hormonal estrogen. Two well-known isoflavones are daidzein and genistein.

MISO a condiment (similar in texture to peanut butter) made with soybeans, rice or barley, and salt, and fermented with microorganisms for one to three years. "Quick"miso is pasteurized and aged for only a few days and has a less complex taste.

NATTO cooked whole soybeans fermented with microorganisms. With its strong flavour, some call natto the Asian answer to blue cheese.

SHOYU Traditional Asian soy sauce made from the liquid pressed from miso paste. Most soy sauce sold in the United States is unfermented and made from defatted soybean meal (mashed soybeans that have had the fat removed from them)

SOYMILK unfermented liquid made from soaked ground and cooked whole soybeans and water (also available as low fat soymilk, which may contain soy protein isolate)

SOY PROTEIN ISOLATE An unfermanted highly refined soy protein used to make soy burgers soy shakes baked goods and other foods.

TAMARI another name for traditional soy sauce (or shoyu)

TEMPEH cooked and fermented whole soybean cake. Can be eaten whole or crumbed into dishes.

Processing and cooking deactivates all the trypsin inhibitors." Biochemist Irvin E. Liener, Ph.D., professor emeritus at the University of Minnesota, reviewed the studies done on trypsin inhibitors and concluded that most soyfoods on the market retain 5 to 20 percent of the trypsin-inhibitor activity of raw soybeans. His findings appeared in the Journal of Nutrition in 1995. In that same issue, researchers Robert L. Anderson, Ph.D., and Walter J. Wolf, Ph.D., of the U.S. Department of Agriculture's (USDA) National Center for Agricultural Utilization Research in Peoria, 11, reported that fermented soyfoods such as miso and soy sauce, generally have lower levels of trypsin inhibitors than soyfoods that are processed and cooked but not fermented.

Recommended for their anticarcinogenic effects, it becomes important to establish the upper limit of exposure at which one can expect this preventive effect against cancer but beyond which one runs the risk of incurring adverse effects that have been generally ascribed to the protease inhibitors (which include trypsin inhibitors).


Does Soy Prevent the Absorption of Minerals?
The bran or hulls of seeds, found in beans, grains, nuts, and other plant foods, contain phytates (or phytic acids). These phytates bind to essential minerals such as calcium, iron, and zinc in the digestive tract and prevent them from beine, absorbed.
Soybeans possess a lot of phytates; some researchers say more than other beans. Additionally, soy's phytates are so strong that many survive phytate reducing techniques such as cooking. (The phytates in whole grains can be deactivated by some soaking or fermenting., techniques.)
Fallon and Enig say only long periods of soaking. and fermenting as are used in making miso, natto, shoyu, tamari, and tempeh (but not tofu, soymilk, texturised soy protein, or soy protein isolate)significantly reduce the phytate content of soybeans. Anderson and Wolf, in their article in the 131?mal of Nutrition in 1995, also report that tempeh has lower phytate levels than unfermented soy foods. Fallon believes that eating more than 12 g of these unfermented foods a day (equal to about a tablespoon) can lead to a shortage of crucial minerals.

But not everyone agrees that phytates are a bad thing. nev can move excess minerals out of the body. Stephen Holt, NI.D a gastroenterologist and author of The Soy Revolution: 71e Food of the Nayt iVIillennium (i\l. Evans and Company, 1998), says phytates shield us from dangerously high levels of minerals such as iron. And some animal studies have suggested that phytates stop the growth of cancerous tumors. In Earl Mindell's Soy ildiracle, Nlindell writes that phytates can bind with minerals that feed tumours.


Does Soy Cause Hormone Havoc?
The plant estrogens (phytoestrogens) found in soy, including isoflavones, resemble the natural estrooens in our body. This could be why soy consumption promises relief from menopausal symptoms, among other benefits. Yet critics of soy say these isoflavones could cause two specific problems First, some researchers speculate that an isoflavone?rich diet could interfere with our
ability to reproduce. Scientists have linked `infertility to the soy diet of animals such as cheetah and quail. For example, researchers at the Children's Hospital Medical Center in Cincinnati, Ohio, analyzed the diet of cheetahs living in zoos to figure out why the animals experienced infertility. In the journal Gastroenterology in 1987, the researchers theorized that the cheetahs' phytoeostrogen soy rich diet was probably a major factor.
Messina says it 1 s possible but unlikely that soy could affect fertility, "but as far as 1 know there's no problem with reproduction and fertility in the Japanese population or in the American vegetarian population [two groups that cat soy]."

According to Soyatech, Inc., a soy research firm in Bar Harbor, Maine, the estimated daily soybean consumption was 9g per capita in China and 30g per capita in Japan in 199 1. In the United States, the estimated daily consumption was 7. 5 g per capita in 199 1; it rose to 11.2 g in 1996. One cup of cooked soybeans equals 180 g.)

Second, a few researchers question if isoflavones could interfere with the hormonal and sexual development of children. Cliff fivine, D.Sc., a reproductive endocrinologist at Lincoln University in Canterbury~ New Zealand, studied the isoflavone levels in soy infant foods and found that the daily recommended intake of soy formula provides 3 mg of isoflavones per Mogrim of body weight - a level he says is more than four times the level found to change reproductive hormones in women.

His findings were published in Proceedings of the Society for Experimental Biology and Medicine in March 1998.
The findings of Irvine and other researchers led some New Zealand residents to lobby for a ban on the sale of soy infant formula except by prescription. The New Zealand government recently decided not to ban the formulas but rather to accelerate studies of possible Adverse effects.
In America, the infant formula concern has received much less publicity but Daniel M. Shechan. Ph.D., a researcher at the FDAs National Center for Toxicological Research in Jefferson, Ark., expresses caution. "Infants fed soy?based formulas are part of a large, uncontrolled, and basically unmonitored human infant experiment, with uncertain risks and benefits '." he says,

"There does exist a theoretical basis or raising concerns," Messina says in response to the formula charges. But, he adds, soy formula has been used in the United States for at least 30 years, with in it Any apparent harm to infants. '7o my knowledge there are no letters or case studies published in scientific journals citing problems in soy?fed infants that might be attributed to estrogenic effects. Furthermore. many short term studies that have evaluated infants and children fed soy infant formula have concluded that soy formula promotes normal growth and development." m

GENISTEIN AND CANCER: ENEMIES OR ALLIES

There is much talk, and hope, in the soy research community that say genistein, one of the isoflavones, can prevent and even cure cancer. Because genistein's molecular structure resembles the hormone estrogen, it is said to occupy estrogen receptor sites on cells and block the ~ of hormonally induced tumors such as breast cancer tumors. Human and animal studies have shown that isoflavones can reduce tumors, There is also evidence that genistein might foil the formation of " new blood needed to feed a growing tumour as well as induce immortal cancer cells to die. 
However, some studies have contradicted these findings. Wilham G. Hetfench, Ph.D., a researcher at the University of Illinois, found that human estrogen?dependent breast cancer cells injected into mice multiply if the mice are fed genistein. His findings were published in Cancer Research in September 1998.
'We've seen a lot of good research that suggests that genistein is a cancer preventer, but it is dangerous to people who already have cancer," Helferich says. "Caution is warranted."
There is no solid explanation why the research is contradictory. One theory is that the full complement of isoflavones and other components as they occur naturally in foods is needed to produce positive results, not just one isolated substance such as genistein. "The jury is still out as to whether soy or genistein reduces cancer risk,' says Mark Messina, Ph.C., co?author of The Simple Soybean and Your Health (Avery, 1994). 'The most solid research is that soy lowers cholesterol. Almost everything else is speculative, though very encouraging. ... My opinion is that the isofiavones are safe as long as you take an amount that you could reasonably get from soyfoods."