Consider that soya beans themselves are rarely eaten as beans: they don't taste very nice and both animals and humans find them difficult to digest. They're routinely processed into a host of “food-like substances” (Pollan). Before they get anywhere near your plate, soya beans will have received some or all of the following treatments: multiple heat-treatments, pressure, cracking and crushing, chemical extractions, treatment with acids, alkalis and enzymes, bleaching, addition of preservatives, supplements, colouring and flavouring, and finally molding into some shape to make it seem to be something it's not. All this doesn't sound a very good way to produce wholesome food.
As you might expect, soya indeed presents several health issues. However, add in GM soya and these health concerns are raised to a whole new level.
Animal feeding studies
In animal feeding experiments comparing GM-soya with non-GM-soya, seven out of twelve studies have so far indicated problems in the GM-fed group.
Classic 90-day feeding trials, which are the standard safety test for foods, do not reveal any problems. However, the more sophisticated measurement techniques now available to scientists are increasingly demonstrating promisis of chronic toxicity.
Vulnerable individuals such as the young, the elderly, or those whose diet or health is poor are especially at risk.
Heavy processing of conventional soya is necessary to remove the phytate and other anti-nutrients which interfere with our absorption of dietary iron. Soya also exerts a pronounced inhibitory effect on our calcium and zinc absorption.
GM soya may have residues of Roundup weed-killer in it because the plants have been specially designed to absorb and accumulate this herbicide. This makes the problem worse: Roundup binds minerals such as magnesium and calcium; it makes them unavailable to the plant and unavailable to the consumer of the plant.
Hormone disruption and cancer (the two are intimately connected)
Conventional soya contains a host of biologically active plant substances, including phyto-oestrogens (isoflavones) which can interfere with human hormone balance and the regulation of our physiology. This has special implications for embryonic and child development, and in the promotion of cancer.
- Soya intake has been linked with cognitive impairment and infant leukemia.
- Men given soya protein supplements exhibited significant increase in blood 'insulin-like growth factor-1' which is linked to cancer.
- Soya has been linked to bladder cancer. The bladder, being the main route of excretion, is exposed to high concentrations of the many biologically active substances found in less-processed forms of soya.
The perception of soya as a healthy choice is not supported by the science. An American Heart Association review of 22 investigations into soya's ability improve blood cholesterol, blood pressure, and post-menopausal bone loss, and into the efficacy and safety of soya isoflavones in preventing or treating cancer concluded “earlier research indicating that soy protein has clinically important favorable effects as compared with other proteins has not been confirmed”.
GM soya may have residues of Roundup weed-killer because the plants have been specially designed to absorb and accumulate this herbicide. This makes the problem worse: Roundup is being increasingly linked to cell toxicity, and to embryo and DNA damage.
Studies have found that conventional soya crops readily absorb common pollutants (such as triclosan disinfectant) from the human manure and recycled water used on fields. These chemicals make their way into the beans themselves and may well accumulate through our food chain. This will add to the glyphosate, surfactants and other commercially confidential adjuvants absorbed and accumulated in Roundup Ready GM soya.
And if all that isn't bad enough:
- there's the safety question of high levels of glutamates in soya; glutamates have been linked to nerve-cell destruction and to obesity through stimulation of insulin cells.
- there's the (untested) safety question of the residues of petroleum-based solvent used to extract the protein in non-organic soya products.
- there's the (untested) safety question of how your fat digestion, your fat absorption and your liver are affected by the modern very extensive exposure to artificial fat emulsifiers (mainly soya lecithin) in just about every processed food you can imagine.
(This article is adapted from Why look out for GM soya? which originally appeared on GM-free Scotland in February 2011.)
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