For many years soya has been hailed as the ‘wonder stuff’ of the health food world. There has, however, also been controversy in the media over the potential for negative effects caused by its consumption. Let us fill you in on some of the facts.
The soya bean, part of the legume family, has been grown in the Far East for thousands of years, where its health benefits have become common knowledge. In Japan, certain soybean based dishes, such as miso soup, have long been considered as a cure-all. With the Eastern reputation for good health, long life expectancy and healthy diets, soya products have now been accepted into the Western diet as healthy ingredients.
However, soya products are being consumed in the West in a rather different way to how they are in the East. While the Japanese tend to stick to fermented soya products such as miso, natto and soy sauce, or with processed products, such as tofu, they only eat it in moderation, accompanied by other ingredients (such as iodine-rich sea vegetables). Westerners, on the other hand, have adopted various soya and soya based products as a substitute for a multitude of meat and dairy ingredients, eating them in much larger quantities than the Japanese would and on a more regular basis, which can be unhealthy. Additionally, with products such as tofu it is important to use organic or traditionally made products which use natural ingredients and setting agents in order recipe positive health benefits from it.
In terms of nutritional value, soya has the highest protein content of any bean. It has the unique advantage over other legumes of containing all 8 essential amino acids and it has fatty acids including omega 3 and 6. On top of this it is very low in saturated fat and has potential cholesterol lowering properties.
Over the years studies have suggested that soy products can be beneficial to human health in numerous ways. One of these is in the reduction of cholesterol which in turn reduces the risk of heart disease, one of the biggest killers in the West. Research has indicated that the isoflavones in soya decrease LDL cholesterol (known as ‘bad’ cholesterol) but have no effect on HDL cholesterol (known as ‘good’ cholesterol) and significantly improve lipid profiles in blood [1,2,3].
These same isoflavones are also said to help in the prevention of osteoporosis (bone loss) , menopause symptoms (including hot flushes), and other studies are currently being done regarding their potential preventative effect on certain cancers (including breast  and prostate cancer ). In summary, there is a wealth of evidence and scientific research to suggest that soya has health providing properties. Research has even led the UK government’s Joint Health Claims Initiative (JHCI) to encourage the consumption of at least 25g of soya protein per day.
However, in recent months there has been a strong emphasis on the potential dangers of eating soya products in the media, which are said to include adverse effects on thyroid functions and fertility. As well as all their positive attributes, isoflavones are said to be responsible for concerns over thyroid function too. Despite this, recent research suggests that it is probably not necessary for people with thyroid function problems to avoid soya. The key would be to ensure that there is also enough iodine in their diet as iodine promotes healthy thyroid functions (iodine-rich foods include sea vegetables, peanuts and raisins).
With the fertility concerns a lot of the information covers the use of soya based baby formula and the consumption of tofu. There is no perfect substitute for breast milk, which is the most natural food for infants. Also refined soya products may not be as healthy as unrefined or fermented ones.
Overall, soya’s safety has been reviewed by a number of major Western committees including the UK Committee on Toxicity and the US Food and Drug Administration who still believe it to be a safe food.
Ultimately, there is no such thing as a ‘wonder food’, but soya is a valuable food source which can be beneficial in our diets. Like most things it should be consumed in moderation and as part of a balanced diet. In Asia they tend to eat between 10 and 25g of soya protein per day and this is predominantly in the form of fermented soya products such a soy sauce, miso and natto or as whole fresh or dried beans which have greater nutritional value. They almost never drink soya milk and tofu is eaten in moderation, accompanied by iodine-rich foods.
Clearspring believe that this is a sensible approach to eating soya. It is also advisable to avoid heavily processed, refined or GM soya products as they may contain higher levels of toxins and possible carcinogens with lower levels of beneficial antioxidants and isolavones than unrefined products. Research into the health benefits and possible risks of soya products is still at an early stage, but the nutritional benefits of it cannot be denied.
By Celia Plender