Marketed as a super food with almost magical properties, soya protein is found in almost everything we eat. However, soya needs to be consumed with abundant caution
Soya has been touted as one of the wonder foods of the 20th and 21st century. The fact that Indians are largely vegetarian, and therefore need an alternate source of protein in their diet (other than meat) has meant an uptake in the production and consumption of soya in its various forms. While soya products come in various forms—soya milk, tofu, soy flour, soy sauce, it is the soya granules that are most visible in terms of market sales in India. Sold packed and branded, as well as in loose form in the market, soy granules are added to vegetable dishes to boost the protein content of the food. A 200g soya pack costs around Rs 18 in the market. Ruchi Soya (Nutrela) is the most visible brand in the market.
If compared, Indias consumption of soya would be miniscule to what the West consumes. Within two decades, soya has infiltrated the western daily diet in many ways. Analysts say that soyas PR spin is: ‘if a little is good for you, a lot must be really good for you. Sceptics have rubbished this maxim in the case of soya and say that consuming too much of soya can actually be dangerous.
Soya benefits versus health concerns
The good thing about soya is that it is low in fat and is a reasonable source of protein. In the US, food labels are allowed to claim that soya is ‘heart-healthy. However, soyas negative points outweigh its health benefits.
Soya beans, as found in nature, are not suitable for human consumption. Only after fermentation for some time, or extensive processing, including chemical extractions and high temperatures, are the beans—or the soya protein isolate—suitable for digestion. A diet high in soya is a diet high in plant estrogens. Research studies in both humans and animals have found that isoflavones in soya can have profound effect on health, raising levels of estrogens significantly. Proponents claim plant estrogens are ‘safer because they are natural, but this is simply not true. High levels of circulating oestrogen are a cancer risk—whatever the source.
Soya proponents often argue that studies that do show adverse effect use high doses of soya that are not relevant to real-world conditions, but how would they know? Some form of soya, usually the protein isolate, is in 60 per cent of all processed food, which means most of us eat soya, without thinking and without knowing, every single day.
GM contamination in soya
A very large percentage of soya—more than 90 percent—is genetically modified, and soya also has one of the highest percentages of contamination by pesticides of any of the foods we eat. GM soya has been found in a range of food items labeled ‘organic’ or ‘GM free’. A 2004 study at the University of Glamorgan, published in the British Food Journal, found that one-fifth of soya-based products on sale at health food shops and supermarkets contained as much as 0.7 percent GM material. The products included vegetarian burgers, cheese substitutes, soya milk, vegetarian sausage mix, soya beans and soya flour.
Soya flour is used in bread; soya oil is in margarine and is the main component of the ubiquitous ‘vegetable oil’ found in a variety of food products. If you eat conventionally reared meat you are eating soya-fed animals. Soyabean concentrate is used to bind foods together and boost protein content, and soya lecithin, the emulsifier E322, is one of the most widely used food additives (read chocolate labels to find out). It is found in health drinks, ice creams, yoghurts, meat substitutes, sweets, infant formula, bakery goods, breakfast cereals, drinks, margarine, pasta and processed meats.
“Only half the rats fed GM food survived”
A Russian biologist, Irina Ermakova, researched the effect of genetically-modified soya on rats, and found that the survival rate of the mice pups fed with GM soya was only 50 per cent. Those who survived did not develop well and were infertile.
The rat pups were divided into three groups. One group was fed on the standard rat food, the second group was fed on food and traditional soya, and the third group was fed standard food and GM soya. Five grams of soya was given everyday to each pup. While the rat pups in the first and second group were healthy, the third group suffered high mortality and deformities.
Most recently, a study at the Harvard School of public Health, in Boston, found that men who regularly ate soya had significantly lower sperm counts.
Our enthusiasm for all things soya also means we ignore the fact that all soya is not created equal. Traditional fermentation of soyabeans significantly reduces some of its harmful properties. As a result, soya products such as tempeh and miso can be beneficial if eaten in moderation, but non-fermented soya products such as tofu and soya milk may be less beneficial.
Finally, soya is an environmental concern. Huge tracts of rainforest are being cut down to feed the greed for this ‘healthy’ food, and to improve yields farmers are encouraged to grow genetically modified varieties, which require even more pesticides.
It seems heresy in a world drowning in soya, but it is possible to have a healthy diet and never eat soya at all. Given the way we have allowed it to infiltrate the food system, though, it would now take a monumental effort to exclude it entirely from your diet A situation that makes a mockery of the notion of informed consumer choice.
What’s wrong with soya?
Allergens: Soya allergies are on the rise as soya consumption goes up. These days, allergies to soya proteins – the symptoms of which include rashes, diarrohea, vomiting, stomach cramps and breathing difficulties – are almost as common as those to milk.
Phytates: These substances can block the uptake of essential minerals – such as calcium, magnesium, iron and especially zinc – in the intestinal tract. All beans contain phytic acid, but soyabeans have higher levels than any other. Children who do not consume fish or meat products to counterbalance the effect of their high-phytate, soya-and rice-based diets have been shown to suffer nutritional deficiency illness, stunting, rickets and other developmental problems.
Enzyme inhibitors: Soya contains potent enzyme inhibitors, which block the action of trypsin and other enzymes needed for protein digestion. Normal cooking does not deactivate these substances, which can also cause serious gastric distress and reduced protein digestion, and can lead to chronic deficiencies in the uptake of essential amino acids such as methionine and leucin, as well as isoleucine and valine. These are all needed to combat stress, avoid depression, synthesise new body protein and maintain a healthy immune system.
Hemagglutinin: Soya products also contain another chemical, hemagglutinin, which promotes clumping of red blood cells. These clumped red cells are unable fully to take up oxygen and carry it, via the bloodstream, to the body’s tissues and organs. Hemagglutinin has also been observed to act as a growth depressant. Although the process of fermenting soyabeans does deactivate hemagglutinin, cooking and precipitation do not.
Phytoestrogens: Soya contains high levels of oestrogen mimics known as isoflavones, which can disrupt hormone function in both men and women. High levels of circulating oestrogens are a risk for certain types of oestrogen-dependent cancers, for instance of the breast, ovaries and testicles. Animals studies have linked high consumption of isoflavones with infertility and reduce immunity.
Antithyroid agents: The plant oestrogens in soya can also cause an underactive thyroid and are implicated in thyroid cancer. In infants, consumptions of soya formula has ben linked to autoimmune thyroid disease.
Aluminium: To manufacture soya protein isolate—the high-protein derivative of soya that is used in snacks, infant formulas, protein bars, breakfast cereals, baked goods, ice creams and yoghurts–soyabeans are first mixed with an alkaline solution to remove fibre, then precipitated and separated using an acid wash and, finally, neutralized in an alkaline solution. Acid washing in aluminium tanks leaches high levels of aluminium into the final product. As result, soya-based formula can contain around 1,000 per cent more aluminium than is found in conventional milk-based formulas.
Reference: The Ecologist