Should we worry about soya in our food?

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http://www.guardian.co.uk/food/Story/0,,1828158,00.html

 

Should we worry about soya in our food?

 

Whether you know it or not, you'll probably be eating soya today. It's

in 60% of all processed food, from cheese to ice cream, baby formula to

biscuits. But should it carry a health warning? Felicity Lawrence

investigates

 

Tuesday July 25, 2006

The Guardian

 

For Dr Mike Fitzpatrick, the saga of soya began in Monty Python-style

with a dead parrot. His investigations into the ubiquitous bean started

in 1991 when Richard James, a multimillionaire American lawyer, turned

up at the laboratory in New Zealand where Fitzpatrick was working as a

consultant toxicologist. James was sure that soya beans were killing his

rare birds.

 

" We thought he was mad, but he had a lot of money and wanted us to find

out what was going on, " Fitzpatrick recalls.

 

Over the next months, Fitzpatrick carried out an exhaustive study of

soya and its effects. " We discovered quite quickly, " he recalls, " that

soya contains toxins and plant oestrogens powerful enough to disrupt

women's menstrual cycles in experiments. It also appeared damaging to

the thyroid. " James's lobbying eventually forced governments to

investigate. In 2002, the British government's expert committee on the

toxicity of food (CoT) published the results of its inquiry into the

safety of plant oestrogens, mainly from soya proteins, in modern food.

It concluded that in general the health benefits claimed for soya were

not supported by clear evidence and judged that there could be risks

from high levels of consumption for certain age groups. Yet little has

happened to curb soya's growth since.

 

More than 60% of all processed food in Britain today contains soya in

some form, according to food industry estimates. It is in breakfast

cereals, cereal bars and biscuits, cheeses, cakes, dairy desserts,

gravies, noodles, pastries, soups, sausage casings, sauces and sandwich

spreads. Soya, crushed, separated and refined into its different parts,

can appear on food labels as soya flour, hydrolysed vegetable protein,

soy protein isolate, protein concentrate, textured vegetable protein,

vegetable oil (simple, fully, or partially hydrogenated), plant sterols,

or the emulsifier lecithin. Its many guises hint at its value to

manufacturers.

 

Soya increases the protein content of processed meat products. It

replaces them altogether in vegetarian foods. It stops industrial breads

shrinking. It makes cakes hold on to their water. It helps manufacturers

mix water into oil. Hydrogenated, its oil is used to deep-fry fast food.

 

Soya is also in cat food and dog food. But above all it is used in

agricultural feeds for intensive chicken, beef, dairy, pig and fish

farming. Soya protein - which accounts for 35% of the raw bean - is what

has made the global factory farming of livestock for cheap meat a

possibility. Soya oil - high in omega 6 fatty acids and 18% of the whole

bean - has meanwhile driven the postwar explosion in snack foods around

the world. Crisps, confectionery, deep-fried take-aways, ready meals,

ice-creams, mayonnaise and margarines all make liberal use of it. Its

widespread presence is one of the reasons our balance of omega 3 to

omega 6 essential fatty acids is so out of kilter.

 

You may think that when you order a skinny soya latte, you are choosing

a commodity blessed with an unadulterated aura of health. But soya today

is in fact associated with patterns of food consumption that have been

linked to diet-related diseases. And 50 years ago it was not eaten in

the west in any quantity.

 

In 1965, the earliest year for which the Chicago Board of Trade keeps

figures, global soya bean production was just 30m tonnes. By 2005, the

world was consuming nine times that a year, at 270m tonnes. World soya

oil production, meanwhile, has increased sevenfold over the same period,

from 5m tonnes to 34m tonnes a year.

 

To feed demand, new agricultural frontiers are being opened up in

Brazil, where large areas of virgin rainforest have been illegally

felled to make room for the crop. US-based transnationals are now

exporting soya back to China, the country from which it originated, as

newly urbanised Chinese switch to industrialised western diets. Thanks

to US agribusiness, we have developed an apparently insatiable global

appetite for the bean produced by farmers in the Americas.

 

James and Fitzpatrick became convinced early on that this entirely new

dependence on soya was, in fact, a dangerous experiment. The dead

parrots were no joke - they were the canaries in the coalmine.

 

For James and his wife Valerie, breeding the exotic birds down under was

a retirement dream. They wanted to feed their young birds the best, so

they began giving the chicks a soya feed. Parrots do not eat soya beans

in the wild but the high-protein animal feed had been marketed in the US

as a new miracle food.

 

The result was a catastrophic breeding year. Some of the birds were

infertile; many died. Other young male birds aged prematurely or reached

puberty years early. " We realised there was some sort of hormonal

disruption going on but we'd eliminated other possible hormone

disrupting chemicals such as pesticides from the inquiry, " Fitzpatrick says.

 

So the toxicologist began a systematic review of the scientific

literature on soya. After finding out about the plant oestrogens in

soya, Fitzpatrick says, " My next thought was: what about children who

are fed soya milk? " He calculated that babies fed exclusively on soya

formula could receive the oestrogenic equivalent, based on body weight,

of five birth control pills a day.

 

In fact, it had been known since the early 1980s that plant oestrogens,

or phyto-oestrogens, could produce biological effects in humans. The

most common of these were a group of compounds in soya protein called

isoflavones. Food manufacturers had variously marketed soya foods as an

antidote to menopausal hot flushes and osteoporosis, and as a protective

ingredient against cardiovascular disease and hormone-related cancers.

Large quantities of mainly industry-sponsored scientific research have

been produced to back up these claims. The American soya industry spends

about $80m every year, raised from a mandatory levy on producers, to

research and promote the consumption of soya around the world. The rash

of new soya foods can be seen as the latest in a line of innovative ways

devised to use soya.

 

The hypothesis behind the health claims is that rates of heart disease

and certain cancers such as breast and prostate cancer are lower in east

Asian populations with soya-rich diets than in western countries, and

that the oestrogens in soya might therefore have a protective effect.

 

Fitzpatrick, however, looked into historic soya consumption in Japan and

China and concluded that Asians did not actually eat that much. What

they did eat tended to have been fermented for months. " If you look at

people who are into health fads here, they are eating soya steaks and

veggie burgers or veggie sausages and drinking soya milk - they are

getting over 100g a day. They are eating tonnes of the raw stuff. "

 

Mass exposure to isoflavones in the west has only occurred in the past

30 years due to the widespread incorporation of soya protein into

processed foods, a fact noted by the Royal Society in its expert report

on Endocrine Disrupting Chemicals in 2000. When the independent experts

on the scientific committee on toxicity trawled through all the

scientific data, they concluded that soya milk should not be recommended

for infants even when they had cow's milk allergies, except on medical

advice, because of the high levels of oestrogenic isoflavones it contains.

 

On breast cancer, they decided that " despite the suggested benefits of

phyto-oestrogens in lowering risk of developing breast cancer, there is

also evidence that they may stimulate the progression of the disease " .

The lower risk of certain cancers among Asian populations might be due

to other factors - their high consumption of fish, for example. They

advised caution. On the effects on menopause symptoms, the evidence was

inconclusive, the experts ruled. On bone density, the committee thought

there might be some protective effects, but the data was unclear. The

evidence on prostate cancer was mixed. Since isoflavones cross the

placenta, the implications of pregnant women eating large quantities of

soya were unclear. There was some evidence that soya-based products had

a beneficial effect on the good HDL cholesterol but they were not sure

that was down to the isoflavones. On the other hand - reassuringly -

they judged that a study linking soya consumption to decline in

cognitive function was not convincing.

 

What the committee also pointed out was that the way soya was processed

affected the levels of phyto-oestrogens. Traditional fermentation

reduces the levels of isoflavones two- to threefold. Modern factory

processes do not. Moreover, modern American strains of soya have

significantly higher levels of isoflavones than Japanese or Chinese ones

because they have been bred to be more resistant to pests. (One way to

tackle pests is to stop them breeding by making them infertile. It turns

out that unfermented soya did play one role in traditional Asian diets -

it was eaten by monks to dampen down their libido.)

 

Sue Dibb, now food policy expert at the National Consumer Council, was a

member of the CoT working group that compiled the final report. She

questions whether infant soya milk should still be on public sale and is

troubled by the latest marketing of soya. " We looked in detail at the

claimed health benefits for adults for soya consumption and concluded

there was not sufficient evidence to support many of them. There may be

benefits but there are also risks. The groups of adults of particular

concern are those with a thyroid problem and women with

oestrogen-dependent breast cancer. It worries me that soya is being

pushed as a health food by a big soya and supplements industry. We ought

to be taking a more cautious approach. "

 

The Food Standards Agency advice is that soya's potential to have an

 

adverse effect on babies' hormonal development is still controversial,

but that soya formula should only be given to infants under 12 months

old in exceptional circumstances.

 

Professor Richard Sharpe, head of the Medical Research Council's human

reproductive sciences unit at Edinburgh University, was also a member of

the committee's working group on phyto-oestrogens in food. He has been

studying the decline in male fertility in the past half-century. He

recently completed studies on the effects of soya milk on young male

monkeys which showed that it interferes with testosterone levels. " In

the first three months after birth, baby boys have a neonatal

testosterone rise. The testes are very, very active in hormone

production at this point and there is a lot of cell activity going on

that will determine sperm count in adults and will affect the developing

prostate. If you introduce a phyto-oestrogen, which can, in large

amounts, alter these changes, you may predispose children to later

disease. Soya formula milk is a [recent] western invention. There is not

the historical evidence to show it is safe. "

 

Manufacturers, however, argue that soya infant formula has been widely

used without problems. " The industry has said that if the CoT comes up

with clear science, we will take note, but the case is not proven, " says

Roger Clarke, director general of the industry's Infant Dietetics Food

Association. " A lot of the work it looked at was based on experimental

work with animals. There does not seem to be clear evidence of adverse

effects, and there is demand for it. There are some markets, such as

vegan usage, where soya is the only alternative. "

 

While 30-40% of all infants in the US are raised on soya formula - not

least because it is given away in welfare programmes - soya milk for

babies has always been confined to a small minority in the UK. So does

Sharpe think exposure to soya from other sources - vegetarian soya

proteins, the soya flour in factory bread, the hydrolysed proteins added

as flavourings, for example - has a cumulative effect that might be

worrying to other age groups? He says he is not concerned about people

who eat soya foods in moderation or in the way they are traditionally

used in oriental diets, but when it comes to modern processed foods,

which use soya proteins in different ways, he prefers to turn the

question round. " If someone said they were adding a hormone to your

foods, would you be happy with that? There may be lots of effects, some

of them may be beneficial, but would you be happy with that? I am not a

fan of processed foods, full stop. And these quick fixes for protecting

against ill-health - you know they can't be true, " he adds.

 

A steaming hiss fills the kitchen of the top London restaurant Nobu,

even after the lunchtime rush. Japanese chefs are filleting the

evening's fish while stock bubbles and concentrates in its stainless

steel vat behind. Executive chef Mark Edwards hands me a teaspoon of one

of his soy sauces. Cool from the fridge, it is thick, rich, dark and

sweet, yet remarkably clear from its long fermentation. The miso that he

uses to marinade his famous black cod for three days is dense and strong

from its lengthy brew too. Muslin cloths envelop delicate curds of tofu,

made fresh each day and added in small cubes to miso soup.

 

Soya is used in traditional oriental diets in these forms, after

cultures, moulds or precipitants have achieved a biochemical

transformation, because in its raw form the mature bean is known not

only for its oestrogenic qualities but for also its antinutrients,

according to the clinical nutritionist Kaayla Daniel, author of The

Whole Soy Story. Soya was originally grown in China as a green manure,

for its ability to fix nitrogen in the soil, rather than as a food crop,

until the Chinese discovered ways of fermenting it, she says.

 

The young green beans, now sold as a fashionable snack, edamame, are

lower in oestrogens and antinutrients, though not free of them. But raw

mature soya beans contain phytates that prevent mineral absorption and

enzyme inhibitors that block the key enzymes we need to digest protein.

They are also famous for inducing flatulence.

 

Christopher Dawson, who owns the Clearspring brand of organic soy

sauces, agrees. He lived in Japan for 18 years and his Japanese wife,

Setsuko, is a cookery teacher. " I never saw soy beans on the table in

Japan - they're indigestible. "

 

Dawson describes the traditional craft method of transforming the soya

bean through fermentation, so that its valuable amino acids become

available but its antinutrients are tamed. The process involves cooking

whole soya beans, complete with their oil, for several hours, then

adding the spores of a mould to the mix, and leaving it to ferment for

three days to begin the long process of breaking down the proteins and

starches. This initial brew is then mixed with salt water and left to

ferment for a further 18 months, during which time the temperature will

vary with the seasons. The end result is an intensely flavoured

condiment in which the soya's chemical composition has been radically

altered. Traditional miso is similarly made with natural whole

ingredients, slowly aged.

 

Most soya sauces (and misos) are not made this way any more, however.

Instead of using the whole bean, manufacturers short-cut the

fermentation by starting with defatted soy protein meal. Soya veggie

burgers and sausages generally use the same chemically extracted

fraction of the bean.

 

This meal is the product of the industrial crushing process the vast

majority of the world's soya beans go through. The raw beans are broken

down to thin flakes, which are then percolated with a petroleum-based

hexane solvent to extract the soya oil. The remains of the flakes are

toasted and ground to a protein meal, most of which goes into animal

feed. Soya flour is made in a similar way.

 

The oil then goes through a process of cleaning, bleaching, degumming

and deodorising to remove the solvent and the oil's characteristic " off "

smells and flavours. The lecithin that forms a heavy sludge in the oil

during storage used to be regarded as a waste product, but now it has

been turned into a valuable market in its own right as an emulsifier.

 

In so-called " naturally brewed " soya sauces the processed soy protein

meal is mixed with the mould spores and given accelerated ageing at high

temperatures for three to six months. Non-brewed soya sauce, the

cheapest grade, is made in just two days. Defatted soya flour is mixed

with hydrochloric acid at high temperatures and under pressure to create

hydrolysed vegetable protein. Salt, caramel and chemical preservatives

and flavourings are then added to provide colour and taste. This rapid

hydrolysis method uses the enzyme glutamase as a reactor and creates

large amounts of the unnatural form of glutamate that is found in MSG.

 

Most commercial soya milk today is made from soya isolates, although

some of the pioneers of soya foods as health products in Europe avoid

the chemical extraction process and use whole beans to make their milk.

The key selling points for both types of soya milk are that they contain

complete proteins and oestrogenic isoflavones.

 

Bernard Deryckere, president of the European Natural Soyfood

Manufacturers Association, says that his members' products, made using

natural processes, are a healthy alternative to diary products. " A lot

of people in Europe are lactose-intolerant. Soya milk was invented in

China 4,000 years ago and today it's consumed by all types of people as

a cholesterol-free source of quality protein. "

 

Daniel's detailed examination of the history of soya milk, however,

suggests that soya milk was made not to drink, except in times of

famine, but as the first step in the process of making tofu. After the

long, slow boiling of soya beans in water to eliminate toxins, a

curdling agent was added to the liquid to separate it. The curds would

then be pressed to make tofu and the whey, in which the antinutrients

were concentrated, would be thrown away.

 

Dibb points out that if you are drinking non-dairy milk because you want

calcium without cow's milk, there are plenty of other sources such as

green leafy vegetables and nuts. And only those eating extremely limited

diets are likely to be short of protein as adults.

 

Dawson, a lifelong vegetarian, does not drink soya milk and only eats

tofu in moderation. " I will only use a product for my family if there is

200 years of tradition behind it. You are asking for trouble if you take

an isolate from soya - yet so much effort seems to go into taking

industry's waste and turning it into new food. "

 

The effort that has gone into creating the global soya market has indeed

been enormous. Today it is dominated by a handful of American trading

companies. Three of them - Bunge, ADM and Cargill - control 80% of the

European soya bean crushing industry. These three, together with allied

companies, are also estimated to control up to 80% of European animal

feed manufacturing. They dominate the US soya market, and also account

for 60% of Brazil's soya exports.

 

Before the first world war, only a very few soya beans were crushed. The

Americans had begun experimenting with using the protein meal as animal

feed, but farmers were reluctant to take it up because it was

indigestible to chicken and pigs. The oil produced was considered " a bit

of an embarrassment " , according to Kurt Burger, a fats and oils

technical expert at the Society of Chemical Industry, whose experience

in the food industry goes back to 1944. It was mainly used in soaps

because it was considered unpalatable. (Henry Ford later funded research

projects to turn soya into plastic for car parts.)

 

Cottonseed oil, a byproduct of the cotton industry, was the main edible

oil used in the US. But then the combination of disease in monocropped

cotton and demand from European allies in the first world war for oil

both to eat and to make the glycerine needed for nitroglycerine in

explosives, stimulated American soy oil production.

 

It was not until the 1940s that industry worked out how to deactivate

the enzyme inhibitor in the protein meal sufficiently for animals to

tolerate it, and it was only technology taken from the Nazis at the end

of the second world war that solved the problem of the oil's horrible

smell and flavour. That left the way for the US to promote the soya that

suited its agricultural conditions as part of the reconstruction of

Europe through the 1950s. Soya oil exports to Europe tripled under the

Marshall Plan, and heavily subsidised exports of surplus US soya ensured

the commodity's dominance in animal feed. The subsidies continue.

Between 1998 and 2004, US Department of Agriculture figures show that

its soya farming received $13bn in subsidies from the American taxpayer.

 

Until 2003, the US was the largest exporter of soya. But through the

1990s, multinationals promoted the expansion of the crop in Latin

America, helping finance farmers and building the infrastructure for

soya exports. The attraction of Latin America is that land is cheap and

labour costs are minimal too. Three years ago, the combined exports from

Brazil and Argentina surpassed US exports for the first time. The cost

is now being counted there in environmental damage and social upheaval.

The cost to western consumers may yet be counted in health.