Soy Controversy

Major evidence now exists to suggest Soya bean is inappropriate for human and stock consumption at current levels. As a legume, it is known to contain phytoestrogens - plant versions of the female hormone estrogen. Phytoestrogens first came to the fore when farmers discovered that stock browsing quantities of red clover had reproductive difficulties. Research established that legumes are prime sources of phytoestrogens and this content was playing havoc with the animals reproductive systems.

In recent years, Western women have been encouraged to supplement their diets with Soy products at menopause to keep up their estrogen levels, on the premise that the higher intake of legumes by women in Eastern countries accounts for the apparent lack of menopausal problems there.

International research findings quoted in New Zealand Medical Journal of May 1995 and a Swiss Public Health paper indicated that 100gm of soy product has the estrogenic content of one contraceptive pill. Further research is beginning to reveal more of the Soy story.

Questions about the use of Soya-based infant formulas were first raised in New Zealand in late 1994 when Richard and Valerie James commissioned a scientific study following deaths and early maturing of parrot chicks at their aviary. The chicks had been reared solely on a commercial Soy-based bird-feeding product. The toxicologist carrying out the survey confirmed high levels of estrogenic compounds in the feed, and also in four infant formulas, likening the content to that of contraceptive pills. He confirmed that depending on age, quantity and feeding methods, infants on Soy formula might be consuming the toxic equivalent of up to 12 contraceptive pills a day.

After further studies by the manufacturers and the Ministry of Health, it was announced that there was insufficient evidence to implicate Soy.

More recently, questions were raised again, suggesting that Soy-based infant formulas should be available only on medical prescription. The Ministry of Health finally confirmed that infants with possible thyroid problems should not take Soya, and that it would be preferable if all Soy-based infant formulas were used only under medical supervision.

The Australian College of Paediatricians also warned that the use of Soya-based formulas might produce side effects.

Meanwhile, a variety of press statements were issued following a number of research projects on Soy:

(a) A study by the National Institute of Aging in Hawaii warned people in middle age to stay off tofu because of a risk of contracting Alzheimers disease. The Hawaiian researchers claim that phytoestrogens do not act like natural estrogens, and they are not necessarily good for humans. The 30 year study found that men who reported eating tofu at least twice weekly were 2.4 times more likely to have developed Alzheimers in old age than non-tofu eaters. [NZ Herald 8 June 1998]

(b) An American Academy of Science Report Toxicants Occurring Naturally in Foods stated that phytoestrogens are capable of producing growth of the vagina, uterus and mammary glands, and female secondary characteristics.

(c) A report from the University of Turku in Finland warned that, in doses exceeding the daily intake in Asia, phytoestrogens are potential hormone disrupters in males.

(d) In her book, The Phyto-Factor Maryon Stewart, founder of the British Womens Nutritional Advisory Service, claimed that phytoestrogens act in a similar way to the breast cancer drug tamoxifen in combating hormone-sensitive cancers, protecting against osteoporosis, heart attacks and menopausal flushes.

(e) Working on statistics from the World Health Organization, two official scientific panels concluded there was almost no evidence to suggest a link between phytoestrogens and a reduction of cancer risk. It was noted that while the Japanese and Chinese have lower than average rates of breast cancer, both countries have very high rates of stomach and liver cancer.

(f) The US Food and Drug Administration Center for Toxicological Research warned that phytoestrogens should be regarded as toxic rather than being treated as safe. This is because consumption of phytoestrogens carries an increased risk of goitre and thyroiditis, as well as a significant dose-dependent risk of developing dementia and brain atrophy from the consumption of tofu.

(g) A very significant volume of evidence is now emerging that children fed Soy formulas and women taking Soya products to assist with the menopause are developing serious thyroid problems and autoimmune diseases later in life.

What emerges from all of this material is a major question about the over-use of Soya in both adult and infant diets - especially infant diets, where an entirely foreign product is replacing natures intended food source.

Alternatives

Very little attention has been given in Western countries to the use of goats milk as a first line replacement for babies unable to tolerate cows milk.

Yet goats milk has been shown to be very suitable for the rearing of young of many species. David Mackenzie, the writer of the comprehensive, practical, thought-provoking and readable "Goat Husbandry" had this to say about goats milk in a chapter he called "The Universal Foster Mother":

"To the supreme honour of a place in the heavens, among the signs of their zodiac, the Greeks elevated three of their domestic animals: the Bull who drew their ploughs; the fleecy Ram who clothed them; and Capricorn the Goat.

"The name of the goat who earned this honour for her species was Almalactea - "Foster Milk". Her constellation still brightens the 20th Century sky.

"While relatively few of the newly born of other species can be satisfactorily reared on cows milk, however modified, there is probably not a single species among the larger land mammals whose young will not thrive on suitably adjusted goats milk. The reasons for the high digestibility of the constituents of goats milk have been explained in Chapter 3...

"Humans are ... for the most part, convinced that cows milk, which is designed to suit the fast growth rate of the calf, is perfectly suitable for feeding the slow-growing human infant ... but ... there is a massive collection of scientific evidence to show that all young farm stock, if fed on a diet too rich in digestible protein, are liable to mineral deficiency disease sooner or later."

Needless to say, we should take this to heart with regard to human infants, if we are considering raising them on cow's milk or on soy-based formulas.