I didn't say to make it the main part of your diet, I just said that it is healthy to eat once in a while because it is a complete protein. As long as you eat other proteins as well, I think you're fine.
Secondly, I don't buy that it CAN'T be eaten on a regular basis, I just don't recommend it because perhaps, for some people (and maybe not all people) it may have a negative impact in large quantities.
Soy milk and tofu are all over the place in asia, and there are a lot of dishes from there that have tofu. There are a lot of Asians who are vegetarian for religious reasons, and many eat tofu somewhat regularly. I've heard the argument that there aren't, I just don't believe it based on my experiences.
Danno, the soy used in Asian diets is not the variety popular here. It's almost all fermented soy, and is high-protein, low-estrogen.
Soy – panacea or poison?
Soy “stops cancer and baldness” (1)
“Soy foods can stimulate the growth of oestrogen-dependent tumours and cause thyroid problems.” (7)
“Boosting your Soy intake could reduce your risk of breast cancer” (5)
“A British Government report concluded that there is little evidence that soy foods protect against breast cancer or any other forms of cancer. In fact, soy foods may result in an increased risk of cancer” (8)
Confused?
In the November issue I introduced a food pyramid by Naturopath David Getoff that positioned soy at the top and recommended it to be eaten rarely if ever. But these products fill health food stores, various medical professionals recommend them and have extensively tested them – or have they? Who do we believe?
This month’s crime watch article on soy will examine the following:
• History of the humble soy bean
• It’s role in the Asian
diet
• It’s role in the western
diet- where is it lurking
• Critical questions regarding its safety
• The guinea pigs
Soy Beginnings
The soy plant was initially used as ‘green manure’ or a cover crop plowed under to enrich the soil, and it became known to the Chinese as ‘the yellow jewel’. Soy did not become human food till late in the Chou Dynasty (1134-246 BC), after the Chinese developed a process of fermentation to make it into soy paste, called miso, with the run-off liquid called soy sauce. Tofu came after miso and in Japan, and China it was rarely served as a main course except in monastries where it was eaten with miso or fish stock. Around 1000 A.D fermented soy foods, natto and tempeh entered the food supply. Modern soy products such as soy-protein isolate and concentrate made using highly processed methods were unknown in Asia till after World War II. Furthermore neither soy milk nor infant formula is traditional in Asia. The first person to manufacture soy milk was actually an American missionary and physician Harry Miller. “Claims that soybeans have been a major part of the Asian
diet for more than 3,000 years, or ‘time immemorial’ are simply not true.” (6)
Soy in the Asian diet
According to a spokesman for Cancer Research UK “There’s a lot of research that countries with a high intake of soy in their diet, such as Japan, tend to have lower rates of prostate cancer and some other types, with the active ingredients in soy thought to be isoflavones.” (1).
Sounds very compelling, however let’s elaborate how much soy is actually in the Japanese and Asian diet. According to the soy industry’s own figures Asians eat very little soy; around 9.3 to 36grams per day in China, Japan, Korea, Indonesia, and Taiwan. In comparison a cup of Tofu is 252grams, or soy milk 240 grams (6).
More importantly the quality is hardly comparable, with the Asian countries generally eating their soy already fermented like miso soup, not as tofu, sausages or meat replacement foods. According to Sally Fallon from Weston A Price foundation (leading independent health group) approximately 65% of Japanese calories come from fish while in China the same percentage from Pork. So it is far from the backbone of their diet (8).
Soy in the Western diet
Apart from the obvious where else is soy lurking? Research estimates that soy is present in 70% of all supermarket products and widely used in Fast Food chains. Soy is used to bulk out and bind many processed foods such as sausages, lasagne, beef burgers and chicken nuggets (food firms can then put a higher protein value on them). Even the husk is used for fibre in breads, cereals, and snacks. The big one is in vegetable oil- soy is the most consumed vegetable oil in the world and is used in margarines, salad dressings and
cooking oils. Food labels simply list soy oil as vegetable oil
As well as that 90% of the 200 million tonnes of soy produced annually is used to feed animals (3).
Soy and the Thyroid
According to Mary Shomon editor of
http://www.thyroid-info.com (9)
“Soy products increase the risk of thyroid disease. And this danger is particularly great for infants on soy formula…More than 70 years of human, animal and laboratory studies show that soybeans put the thyroid at risk.”
Dr. Mike Fitzpatrick, an environmental scientist and phytoestrogen researcher who has conducted in-depth studies on soy, particularly the use of soy formulas published in the New Zealand Medical journal. Dr. Fitzpatrick makes it clear that soy products can have a detrimental affect on both adults and infants. In particular, he firmly believes that soy formula manufacturers should remove the isoflavones -- that part of the soy products that act as anti-thyroid agents -- from their products (2)
How do researchers induce thyroid cancers in laboratory animals? They use thyroid-inhibiting foods like soy in combination with thyroid boosting drugs like Synthroid. (6)
How much soy can impair thyroid problems? Perhaps as little as 30 mg or less than a glass of soy milk. (4)
Soy and reproduction
Here is an interesting fact. Tofu is consumed by Buddhist monks to reduce libido. Humans and animals appear to be the most vulnerable to the effects of soy estrogens prenatally, during infancy and puberty, during
pregnancy and lactation – all the major phases of hormonal shifts with growth and development. How powerful can soy be to the hormone system? One landmark study showed “that as little as 45mg of isoflavines could alter the length of a premenopausal woman’s menstrual cycle.” (4) Obviously it’s harder to find a cause and effect relationship as there are many potentially triggers to hormonal imbalances and reproductive problems. However in animals this has been more thoroughly tested. According to Dr Mary Enig (world renowned lipid and hormone specialist) female pigs can only ingest it in amounts no greater than 1% during lactation phase or face developmental problems in the piglets (8).
Soy and the environment
Soy was previously considered a good source of protein which attracted vegetarians looking for meat alternatives. But it’s a double whammy for environmental and health conscious vegetarians as the effect of soy farming on the environment is dramatic. It is predicted that 10,000 hectares of forest every year in Argentina (20 football fields an hour). If this continues at this rate in fives years time the country’s native forests will have disappeared. Similar scenarios are being played out in Brazil, Paraguay and Bolivia all thanks to companies like the genetic engineering giant Monsanto. The World Wide Fund for Nature published a report recently calculating that 22 million hectares of forests and savannah in South America (an area the size of Great Britain) will be wiped out by 2020. Crops have also triggered soil erosion, and the widespread use of pesticides and chemicals are destroying some of the world’s most delicate habitats. (3).
Soy Business
Soy is traded as an international commodity, like oil and gold. It’s a multi-billion dollar industry., "The reason there’s so much soy in America is because they [the soy industry] started to plant soy to extract the oil from it and soy oil became a very large industry. Once they had as much oil as they did in the food supply they had a lot of soy protein residue left over, and since they can’t feed it to animals, except in small amounts, they had to find another market." (2)
Conclusion
So Soy’s reputation as a health panancea is now badly blemished. It still has some supporters, but it is important to examine their background to ensure they are not just PR mouthpieces for a very powerful Soy industry.
Big Soy, like big pharmaceutical, has been a powerful force shaping an
attitude to
nutrition and health. Given the mounting evidence that does not support Soy as a health food I believe we need to be very nervous about accepting big Soy spin as nutritional gospel.
References
1. BBC News 2004, Soy stops cancer and Baldness, 14/11/2004
2.
www.mercola.com/2004/jan/21/soy.htm, Soy: Is it healthy or is it harmful
3. Anthony Barnett, The Observer, They hailed it a wonder food, 7/11/2004
4.
www.soyonlineservice.co.nz/articles/Shadow.htm, Sean Carson, The shadow of Soy or, How I stopped loving and learned to worry about the bean
5.
www.thehealthierlife.co.uk, Soy Health benefits: why boosting your intake of soy could reduce your risk of breast cancer
6.
www.thewholesoystory.com, Whole soy story: The dark side of America’s favorite health food. Daniel, K, T
7. New Zealand Medical Journal (vol 113 Feb 11 2000) Soy Formulas and the effects of isoflavones on the thyroid.
8.
www.westonaprice.org, Myths and Truths about soy food
9.
www.thyroid-info.com, Mary Shomon editor.
