I receive many emails from people raising their concern about soya and asking me to explain the health benefits of this versatile food. For many years soya has been hailed as the ‘wonder food’ 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’s 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 refined products, such as tofu, they only eat it in moderation, accompanied by other ingredients (such as iodine-rich sea vegetables) such as in miso soup.
Westerners, on the other hand, have adopted various soya and soya based products as a substitute for a multitude of meat and dairy ingredients, and eating them in much larger quantities than the Japanese would and on a more regular basis, which can be unhealthy. Another important point to make here is the use in the West of soya milk, soya yoghurt, soya cream, soya cheese, which are not a part of the traditional ‘Asian’ diet. Incidentally these soya milks come in chocolate, strawberry or vanilla flavour and many people are consuming them daily thinking they are a ‘healthy option’ to dairy. Therein lies the problem. Additionally, with products such as tofu it is important to use organic or traditionally made products which use natural ingredients and setting agents to receive 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 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.
Tofu Steaks on Sourdough Buns
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 that you can see below 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.
Tofu & Blueberry Dessert
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.
The thyroid gland has the essential function of controlling metabolism. There are multiple dietary nutrients required for the production of thyroid hormone, iodine being the most widely recognized. The relationship between soy consumption, iodine deficiency and goiter (enlarged thyroid) was first described in 1960 in The New England Journal of Medicine. Infants consuming nonfortified soy-based formula developed goiter, yet the exact nature of the relationship was unclear. Since then, there have been numerous studies which have disproven the causal relationship between soy and thyroid toxicity. – See more at: http://freefromharm.org/health-nutrition/vegan-doctor-addresses-soy-myths-and-misinformation
I have seen so many clients with thyroid issues who are eating a typical western diet. The programme I design for them using the principles of ‘Macrobiotics’ gets their thyroid functioning again in an optimal way. It’s important to note here that the longest living people on the planet who use soya don’t have ‘thyroid problems’. The endocrine system as a whole is normally out of whack when I see these women for health counselling. Trust and learn from the cultures who live a long healthy life, it’s the most common sense thing to do as regards to your health.
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 as 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.
Miso Soup with Tofu
Clearspring foods of which I am a huge proponent and promoter 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. The nutritional benefits of soya cannot be denied.
The many recipes I have created using soya, from miso soup, to tofu burgers, desserts and so much more (some you can see on this blog from my pictures) are all on my website or in my book ‘Macrobiotics for all Seasons.’
Don’t be caught up in the fear mongering of the media who demonize all soya products just as they do with refined and complex carbohydrates by clumping them all together.
Taku K et al., 2008. Soy isoflavones lower serum total and LDL cholesterol in humans: a meta-analysis of 11 randomized controlled trials. Am J Clin Nutr. 2007 Apr;85(4):1148-56
Zhan S, Ho Sc. 2005. Meta-analysis of the effects of soy protein containing isoflavones on the lipid profiles. AM J Nutr. 2005 Feb; 81(2): 397-408.
McVeigh BL et al., 2006. Effects of soy protein varying on isolavone content on serum lipids in healthy young men. Am J Clin Nutr. 2006 Feb; 83(2):244-51.
Yamaguchi M, 2006. Yakugaku Zasshi. Regulatory mechanism of food factors in bone metabolism and prevention of osteoporosis. 2006 Nov; 126(11) :1117-37.
Wu AH ey al., 2008. Soy intake and breast cancer risk in Singapore. Chinese Health Study, 2008 Jul 8:99(1): 196-200
Kurashi N. et al., 2007. Soy product and isoflavone consumption in relation to prostate cancer in Japanese men. 2007 Mar; 16(3): 538-45 Epub 2007 Mar.