Studies are often small and, on closer examination, are sometimes misleading. Conclusions often arise from meta-studies that offer a sort of ‘round up’ of the published data – here the results can be diverse and difficult to quantify. Sometimes the soya effects are seen only in lab rats, other times reactions occur on a petri dish and one study used subjects with obesity issues that could strongly impact on any results.
Certainly one study demonstrated a 30% reduction in bowel cancer risk in those with a higher soy intake, while another study form Harvard University indicates a lower sperm count in men consuming the most soya. They advised that men with fertility issues might be wise to avoid soya products.
In the Eastern world the soya bean has been cultivated and utilized for thousands of years. The versatile crop can be processed to produce soya sauce, tempeh, miso and soya milk. The high protein content means it often accounts for a considerable part of the diet for vegans and vegetarians.
Traditionally the soya would have been naturally fermented and consumed in small amounts, never as a large meal. Now it is eaten as large chunks of tofu to replace meat and is often included in margarines, baking goods and hidden in sundry products. The majority of the soya product we now consume is artificially produced and highly processed using chemical hydrolysis– via acid baths and heat treatment –and often genetically modified. Yum, yum.
One variety of GM soya crop grown, when drenched in glycophoshate (‘Round Up’) weed killer, remains perky and defiant while all the natural plant greenery all around shrivels, blackens and pegs-it. It doesn’t sound great as a natural consumable, and details and question marks over the approval of the crop can be considered in an article in GM-free Scotland.
It is the fact that soya is rich in isoflavones – genistein, daidzein and glycetin – that is both the blessing and the curse of beast. These proteins are phytoestrogens, plant hormones, and have the same biological effect in the body as the female sex hormone, oestrogen (present in in both men and women). The plant hormone can bind to receptor sites in the body in the same way our own naturally occurring oestrogen can. Unsurprisingly, studies have demonstrated the benefit of taking soya as an alternative to HRT in menopausal women.
Breast cancer, which can be very sensitive to the presence of oestrogen, can react to the phytoestrogens in soya; it has been shown to present lower risks in one study, and yet increase the risk in another. Inconclusive but there is no doubt that the close mimicking of our own sex hormone has a tangible effect in the body.
With that in mind, what of soya being used in powdered milk for babies? Cited at an International Soy Symposium in 1998, investigators reported that the daily exposure of infants to isoflavones in soy infant formula is six to eleven times higher on a body weight basis than the dose that has hormonal effects in adults consuming soy foods. Circulating concentrations of isoflavones in infants fed soy-based formula were 13,000 to 22,000 times higher than plasma oestradiol concentrations in infants on cows’ milk formula.
It was estimated that an infant exclusively fed soy formula receives the oestrogenic equivalent (based on body weight) of at least five birth control pills per day (C.Irvine,et al, The Potential Adverse Effects of Soybean Phytoestrogens in Infant Feeding, New Zealand Medical Journal, May 24, 1995).
This high soya intake at a young age has been a suggested link to the increased incidence of precocious puberty in young girls. Certainly the world is now teeming with adults raised on soya milk, and presumably they did not all experience problems as a result, but it would certainly be interesting to know what their experience has been.
Soya also appears to be far from the ‘superfood’ it is sold to us as. It contains naturally high levels of phytic acid, a major inhibitor when it comes to the absorption of key nutrients such as iron, magnesium, potassium and zinc. Mineral deficiencies are a serious consideration for those relying on soya as a protein source.
Farm animals and poultry are reared on a diet that is predominantly soya based (a cheap, protein-rich feed that is free from animal products), so it follows that we too will be consuming the soya through the meat and are perhaps consuming more of the chemicals from soya than we bargained for.
From a conservationist’s perspective, natural forests in South America have been obliterated to make way for the sprouting crop, with natural wildlife species sidelined for profit. In Argentina the area cultivated with soy has increased from 6 to 19 million hectares, which represents 56 percent of Argentina’s cultivated land.
According to Climate Connections ‘soy exports bring in 16,000 million dollars a year, but there are also other consequences: 190 million litres of glyphosate are sprayed and there has been an exponential increase in deforestation. Two hundred thousand families have been driven from their land and there are conflicts between soy producers on one side and peasants and indigenous peoples on the other over eight million hectares of land. However, this production model is promoted as an economic success, and now is even described as “responsible”.’
The food industry is quick to extol the virtues of soya as a superfood. It is promoted as a panacea and sold to us in many guises. Commercially produced with questionable green credentials, using GM crops on a vast scale, and by chemical processing, one wonders if we have been sold a dummy. Perhaps soya is not quite the healthy product we have been led to believe.