SOY OR SOYA BEANS - USEFUL SOURCE OF PROTEIN: HISTORY, USES AND HEALTH BENEFITS OF SOY BEANS

SOYA OR SOY BEANS, GLYCINE MAX 

In British English we say soya bean while in US English it’s a soybean, but they are the same thing. They originated in South-East Asia and were first domesticated in China sometime around 1100 BC. From there they spread to other Asian countries where they were cultivated by the first century AD (including Japan). The soya plant is a member of the Leguminoseae or Fabaceae family which includes lupins, kudzu or pueraria, liquorice, carob, peas, beans, chickpeas, indigo, alfalfa and broom to name but a few. Its wild ancestor is Glycine soja.

  The first European to describe and illustrate the plant was Engelbert Kaempfer, the German botanist, in his “Amoenitatum Exoticarum” published in Germany in 1712. He also gave a detailed description (some say the most detailed to date) of the process of making shoyu (Japanese soy sauce) and miso. Before this date six Europeans had written about soy food products, miso, soy sauce and tofu but they had not realized how it was made and were ignorant of the fact that the products were made from the soya bean.

  Shoyu was imported into Europe long before the soya bean, first by the Dutch in 1670 who supplied it to King Louis XIV of France for use at his banquets. It was a luxury item at that time, just as it had been when it was first introduced into Japan, centuries before. John Locke, the English philosopher, wrote that it was available at a London restaurant in 1679 and during the 18^th century soy sauce was popular in Europe, and widely used in Britain by the end of that century. The famous Lea and Perrins Worcestershire sauce had a base of soy sauce and was spiced up to market it as a different food item.

  The soy plant was grown in Botanical Gardens in France, The Netherlands and England as a curiosity only, during the 18^th century. We know that Benjamin Franklin sent some seeds to a friend of his in 1770, but they didn’t really come into their own until George Washington Carver took an interest in then and realized that they were a valuable source of oil and protein in 1904. He persuaded farmers to rotate their crops and plant nitrogen fixers such as peanuts and soya plants (also sweet potatoes) and then plant cotton in the third year and farmers were amazed to find that the next cotton crop was better than it had been for many years.

  Henry Ford had his scientists make strong durable plastic from soya beans and made a car entirely out of soya bean plastic. When the plant was first introduced into the American colonies by Europeans in 1765 it was called “Chinese vetches.” The soya bean has been one of the five main plant foods in China along with rice, wheat, rye, barley and millet for centuries, but the beans were fist exported to Europe only in 1908.Now soya oil is used for many purposes, in the form of flour it can be added to wheat flour and helps compensate for the lack of the amino acids, tryptophan and lysine in the grain flour. Sixty pounds or one bushel of the beans yields eleven pounds of oil and forty-eight of meal. The oil can be used as a green fuel and lubricant as well as for culinary purposes, while the lecithin extracted from the oil is a natural emulsifier and used to stabilize the ingredients of some food products, as it makes fat and water compatible, and can prevent cocoa butter and chocolate from separating for example. The oil is used in margarines, salad dressing and can be found in paints, varnishes and printers’ ink. The plants themselves have always been used as fodder for animals, so the whole plant is useful.

  Soy beans in our diet have many health benefits and the same is true of tofu, soy milk, tempeh and miso as these soya products contain isoflavones which can lower blood pressure and cholesterol levels. The cooking oil and soya sauce do not contain them however. Soy foods may be beneficial for menopausal and pot menopausal women as they can help maintain healthy bones and a healthy cardio-vascular system. They do not increase the risks of breast cancer as was previously believed, but on the contrary may help protect from it. They can also help to stabilize blood sugar levels and so are helpful to sufferers of Tye-2 diabetes. It is also believed now that they may boost the functions of the brain. Soy protein may also help protect against atherosclerosis by increasing the levels of nitric acid in the blood, which improves blood vessel dilation and inhibits damage caused by free radicals.

  The choline found in soybeans lessens chronic inflammation, while a sphingolipid in the beans, soy glucosylceramide may promote gastro-intestinal health and inhibit the formation of cancerous tumours.

  Soya beans also contain dietary fibre which can reduce the risk of colon cancer. Apart from the substances already mentioned above, soy beans are excellent sources of molybdenum, tryptophan, the minerals manganese, iron, and phosphorous as well as containing selenium, magnesium, copper, calcium, sodium and zinc. They contain the B-complex vitamins, B1 thiamin, B2 riboflavin, B3 niacin, B6 and folate. Soy beans are also sources of the vitamins K, A and C along with Omega-3 and -6 fatty acids, 18 amino acids,  and the isoflavone genistein which may help us stay thin, and which is generally considered to have anti-cancer properties. The beans are also excellent sources of protein and a good substitute for meat, at least occasionally.

  The whole beans are the best for our health, although tofu, soya bean sprouts, tempeh and miso also have some benefits. The beans can be cooked in the same way as chickpeas or borlotti beans, and the fresh green beans (called endamame) are particularly tasty. Unfortunately perhaps the USA is the biggest exporter of soy beans and their oil, and these are GM crops. As we don’t really know what the long-term health effects of GM food are as it has not been around long enough for valid research, it could be that soy beans may not be as healthy as they would appear at the moment. However it is probably true that if eaten in moderation they won’t be very harmful.