Not soy good: health food myths

Not soy good: health food myths

Whether you are a strict vegan or a meat-and-three veg kind of person, chances are you are consuming soybean products in quantities that are questionable for your health. We eat it knowingly, when we blend up a soy smoothie or order a tofu stir-fry, and sometimes unknowingly, in everyday processed foods such as margarine, cooking oils and packet biscuits.

It has been estimated that soybean derivatives can be found in nearly 60 per cent of foods sold in Australia. We have all heard the rave that soybeans will protect us from heart disease, cure cancer and fan away hot flushes too, so what’s the problem, you might ask. The soybean has been sold to the public as something of a miracle bean, after all. The problem is that how the soybean has been marketed and what the soybean actually does are not necessarily the same thing. In fact, eating unfermented soy foods in large quantities can be detrimental to health.

The makings of a miracle bean
In ancient China the soybean was honored with the nickname, The Yellow Jewel, because of its wonderful golden crop cover that enriched the soil. It wasn’t used as a food until the Chou Dynasty in 1134-246 B.C., when the Chinese developed a fermentation process to make soybean paste, best known today by its Japanese name, miso.
Soy sauce, or shoyu in Japanese, was the liquid siphoned off during the production of miso. Natto and tempeh are both fermented soybean foods that came soon after. Fermentation is key to eating soybeans. Sadly it is often what’s left out in the production of the plethora of soy products sold today.

The ancient Chinese almost never boiled or baked soybeans or cooked with soy flour, except in times of famine. Contrary to popular belief, soy milk is not traditional in Asia, nor is soy infant formula. Rural Chinese villagers have probably never seen soy sausages, soy ice-cream, soy chips, tetra cartons of flavoured soy milk, soy energy bars, or any of the other novel soy products that are commonplace here. It is hard to imagine how this humble crop that was traditionally used as a nitrogen fixing, green manure has emerged as an economic, political and, controversially, nutritional giant.

What is known is that the US is the biggest soybean producer, weighing in at 93.9million metric tonnes per year, nearly one third of the world’s production. Claims about the benefits of soybeans have been challenged by scientists to the all too familiar retort: soy foods couldn’t possibly be bad because Asian communities have eaten them for centuries and been free from diseases commonplace in the west.

Truth be known, Asian countries eat soy sparingly and usually only when fermented. A food frequency survey done in Takayama City, Japan, 1998, identified that the soy products most often consumed were tofu, miso, soy milk, and boiled soybeans. The estimated amount of soy protein consumed from these sources was on average between 4 and 8 grams daily. By contrast, one slab of tofu diced into a stir fry or sizzled into a burger pattie contains approximately 200grams, a soy smoothie approximately 240grams.

What’s all the fuss?
It is the chemical makeup of the soybean that is problematic for our bodies. It contains a chemical that mimics oestrogen, inhibits digestion and thyroid function, robs the body of key minerals and contributes to its status as a leading allergen, alongside peanuts and shellfish. Soybeans can cause immediate hypersensitivity such as coughing, sneezing, a runny nose, hives, diarrhea, difficulty swallowing, and even anaphylactic shock. Long-term persistent conditions include sinus and ear infections, joint pain, fatigue and eczema.

The soybean has an inbuilt defence mechanism to protect it from adverse weather and spoilage while growing in the field; these same naturally occurring antinutrients that allow it to survive and thrive, can wreak havoc in our body. Potent enzyme inhibitors block proper protein digestion causing gastric upset, bloatedness and amino acid-related deficiencies. These inhibitors are large, tightly folded proteins that are not completely deactivated during ordinary cooking. Soybeans also contain phytic acid, which scientists generally agree can contribute to widespread zinc, iron and calcium deficiencies in developing countries due to their mineral-blocking effect. And then there are oligosaccharides, the ones that makes us toot. More than seventy years of studies also show that soybeans compromise thyroid function. The chief culprit are goitrogens, a chemical that latches onto iodine to prevent it from being absorbed by the body through the gastrointestinal tract. Iodine is needed to make thyroxine, which is essential for our metabolic rate and normal brain functioning.

Soy’s big drawcard has always been its reputation as a natural hormone balancer. The belief continues that soy hormones are ‘safe’ because they are ‘weak’ and ‘natural’. However, toxicologists from New Zealand and the United Kingdom are now issuing health warnings for those hormonally susceptible especially babies. Dr Kenneth Setchell, Professor of Pediatrics at the University of Cincinnati, and Dr Daniel Sheehan, Director of the US Food and Drug Administration National Center for Toxicological Research, have been extremely vocal about their concerns regarding soy for infants. A vital stage for the encoding of the human reproduction system is straight after birth. The baby’s system surges with endocrine activity; hormonal shifts provide the blueprint for later reproductive development and maturity. Baby boys experience a testosterone surge during the first few months of life that is equal to that of a grown man; the oestrogen levels of baby girls double during the first month of life.

In the years since soy formula has been available, there has been a marked increase reported by pediatricians and parents alike in delayed physical maturation amongst boys (a rise in undescended testicles and an increase in male breast development), while there has been an increase in early onset puberty among girls, who can then experience reproductive problems later in life. Soy products have the ability to block testosterone receptor sites and open up oestrogen receptors. Curiously, Buddhist monasteries traditionally used tofu in the diet to decrease male libido, as did Japanese wives to punish straying husbands.

Regarding menopause,
osteoporosis and breast cancer, the jury is still out on the role played by soy products. Eminent scientists paid by the soy industry convened in 2003 at the Fifth International Symposium on the Role of Soy and concluded the data to be confusing and contradictory. Where to from here? It is not so much that the soybean is a ‘bad’ plant whose foods are detrimental to our health. Soy is a beautiful food for our health if we take on what Asian communities traditionally understood: that fermentation and moderation were the key. The clever marketing of spin doctors and the shortcuts taken in the processing of soy plants into commercial foods has compromised soy’s reputation. The journalist’s rule says: follow the money.

The soybean is a unique plant. Rudolf Steiner noticed that legumes, especially soy, embodied a gesture of ‘taking’ while all other plants were ‘giving’. He also spoke of this plant’s reluctance to leave the earth, which could be mirrored in its difficulty to digest. We haven’t given the Yellow Jewel the respect it requires, to say nothing of genetic modification of this once golden crop.

Nicholas Smith is a naturopath with the Mullumbimby Medical Centre and writes on health for the Sydney Morning Herald and The Age. His website is www.nicholassmith.com.au com.au.

First published in The Byron Shire Echo 14 January 23, 2007 www.echo.net.au Author Nicholas Smith: reproduced with permission from the Byron Shire Echo