Organic food exposed

[S.Annadana]

Magazine feature
Organic food exposed
Issue 16 of Cosmos, August 2007by Elizabeth Finkel


I love my local organic food store. From the moment I enter, I enjoy the aromas that greet me and the folksy look of the place. But is organic food really any better for me? The perceived wisdom is that it's more 'pure' and 'natural', devoid of disease-causing pesticides; that organic farming "generates healthy soils" and "doesn't poison ecosystems with toxic chemicals".

Organic food is riding a surge in popularity; across the globe, sales of organic food are burgeoning. The global market in 2006 was estimated at close to an impressive US$40 billion (A$47.9 billion) by Organic Monitor, an industry research body, and growing 20 per cent annually in the U.S. and Canada.

And where consumers go, the multinational food companies follow: everyone from Uncle Tobys to Kraft, Heinz, Kelloggs and even Coca-Cola has jumped on the bandwagon. And developing countries are joining in too: China's organic exports grew 200-fold in a decade to reach US$200 million in 2004. Australia is also a major exporter, and plans to increase its organic produce by 50 per cent by 2012.

But is this belief in organic food based on faith, or evidence?

THE SURPRISING FACT IS that this mass migration to organic food has not been on the back of scientific evidence. In fact, you'd be hard pressed to find comprehensive evidence that organic food is healthier – either for us or the planet. Nevertheless, in the public consciousness, organic farming is unquestioningly bundled with the reigning moral imperatives of sustainability, protecting the environment and reducing greenhouse gases.

Certainly there are historical reasons for concern. In the 1950s and 1960s, the pesticide DDT was blamed for the widespread thinning of bird eggs across North America, and the rapid decline of the bald eagle and peregrine falcon. Over-intensive grain farming in the U.S. Midwest led to fertiliser run-off into the Mississippi River that ultimately created a 20,000 square kilometre dead zone in the Gulf of Mexico, as algal blooms sucked up available oxygen. Soils that were tilled for decades without crop rotation or replacing organic matter led to dust storms that wreaked havoc across Australia in the 1960s and the American and Canadian prairies in the 1930s, the latter so vividly depicted in John Steinbeck's The Grapes of Wrath.

These days, modern farming techniques have evolved after decades of pressure from the environmental movement and decades of work by a generation of scientists inspired by environmental awareness. In fact, conventional farming is starting to look a lot like organic farming.

The earthworm-rich soils, so prized by organic farmers, are being achieved through contemporary no-till (or no-plough) techniques. In Australia, most farmers use rotation to get crops out of synchronisation with weeds and to return nutrients to the soil. Natural predators are being used to control pests, and companies such as Dow Chemical are producing safe, short-acting pesticides. In fact Dow's latest pesticide, Spinosad, is also happily used by organic farmers because it is naturally produced by bacteria.

"There's been a quiet revolution in Australian farming over the last decade," says Mark Peoples, the assistant chief of the Division of Plant Industry at Australia's national research agency CSIRO.

ON THE OTHER HAND, organic farmers are bound to an ideology that demands they only use natural techniques. In some cases, such purism gets in the way of practices that are better for the environment and more sustainable for farmers. For example, organic farmers will use litres of BT spray (BT is a 'natural' pesticide made by the bacterium Bacillus thuringiensis), yet they often demonise the genetically modified (GM) cotton crops that carry an inbuilt supply of BT, and which therefore require less spraying.

However, these GM varieties spare farmers – and the environment – from the risks of pesticide overuse. For instance, according to Richard Roush, the Dean of land and food resources at the University of Melbourne, cotton farmers in India have reduced their use of pesticides and accidental poisonings by 80 per cent since the introduction of genetically modified BT cotton.

The ultimate test of sustainability is whether organic farming could feed the planet. Scott Kinnear, president of Australia's Organic Farmers Federation, believes "it is imperative that the world moves over to organic farming as soon as possible".

Yet many agricultural scientists estimate that if the world were to go completely organic, not only would the remaining forests have to be cleared to provide the organic manure needed for farming, the world's current population would likely starve.

Norman Ernest Borlaug, the American plant geneticist who won a Nobel Peace Prize for breeding the high-yield, disease-resistant wheat varieties (triggering agriculture's 'Green Revolution'), is despairing of the organic fad. "This shouldn't even be a debate. Even if you could use all the organic material you have – the animal manures, the human waste, the plant residues – and get them back on the soil, you couldn't feed more than four billion people."

TO GET HIGH YIELDS from food crops requires disturbing nature to deliver just what the crops need. First off, crops need fertiliser, which is often nitrogen in the form of nitrate and ammonia, because most plants can't draw nitrogen directly from the atmosphere. (Legumes are a famous exception – their root nodules hold bacteria that turn atmospheric nitrogen into nitrate.) Second, there has to be a way of stopping all the other robust plant and insect species from competing with or consuming your crop.

Non-organic farmers make use of chemicals to achieve these goals. Just prior to World War I, German chemists Fritz Haber and Carl Bosch learned to make ammonia synthetically. Their chemical reaction is still used today to produce more than 450 million tonnes of artificial fertiliser per year, and sustains the agriculture which feeds about
60 per cent of the Earth's population.

Organic farmers source nitrate from manures, gradually broken down by soil organisms. They use only naturally-occurring products to control pests, such as the elements sulphur and copper; pyrethrins and rotenone (both made by plants); BT spray and Spinosad (both made by bacteria). However, these natural pesticides are not harmless. For instance, sulphur irritates the lungs, and rotenone has been shown to cause Parkinson's disease in rats.

Certified organic farmers (those accredited by one or more of the six voluntary associations, from the Organic Growers of Australia to the National Association for Sustainable Agriculture) also subscribe to a code that includes kinder treatment of animals, a commitment to sustainability and environmental health, fair trade and social equity. But many of these practises are also pursued by 'non-organic' farmers. The core distinguishing belief of organic farming is that 'natural is better'. But does this conviction belief stand up to scientific scrutiny?

RACHEL CARSON'S 1962 book Silent Spring unleashed public concern about the dangers of synthetic chemicals, not just to birds and animals, but to humans. The incidence of human cancers were rising and suspicion fell on man-made farming chemicals.

There's no doubt exposure to high doses of pesticides is hazardous to health: in countless studies, high doses given to laboratory animals have caused birth defects, sterility, tumours, and damaged organs. But as any toxicologist will tell you, most chemicals – natural or synthetic, are toxic at high doses. The question is not, "do pesticides cause cancer?" Rather, do the small traces of pesticide residue we eat in our food really cause a problem?

Scientists are unable to test these chemicals directly on humans, so they use rats instead. To establish the maximum dose considered to be safe for humans, they find a dose that's completely safe for rats. Then they divide it by 100. Testing by Australia's national regulator, Food Standards Australia New Zealand, shows that pesticide levels measured in food are either well below the recommended maximum dose or are completely undetectable.

People live about 80 years longer than rats: that's 80 years longer for pesticide cocktails to accumulate and wreak havoc. Even so, it turns out that a lifetime's consumption of synthetic pesticides is a drop in the ocean compared to the natural pesticides we consume from the plants we eat. Plants have evolved a vast pharmacopeia of chemical weapons, and we consume many of these 'weapons' daily: caffeine in coffee, solanine in potatoes and psoralens in celery, to name just three.

Even the freshest organic apples – as well as other plant foods – contain natural compounds which, when extracted and given to rats in high doses, cause tumours. Toxicologist Bruce Ames of the University of California became famous in the 1970s for sounding the alarm on the cancer-causing (or carcinogenic) potential of man-made chemicals.

But after testing 'natural' pesticides in rats, he called off the warning. A paper he published in 1990 said it all. Entitled, "Dietary Pesticides (99.99 per cent All Natural)", it reported that in a regular diet, people consume about 10,000 times more natural carcinogens than synthetic ones. According to Ames, a single cup of coffee contains more natural carcinogens than a year's worth of the pesticide residues eaten on fruit and vegetables.