No scientific evidence showing organic is better

Thu, Jul 5, 2012, 01:00

OPINION:THE MODERN food supply is constantly under attack by activists with a fundamental mistrust of science and technology.

We have NGOs on organic food, on anti-GM and on food miles, all of whom exert a significant impact on the media and on the thinking of both consumers and policymakers. Regrettably, the scientific reality is rarely presented to consumers.

Organically grown food is nutritionally identical to conventional food. That was the conclusion of a study funded by the Danish organic movement, and which was published in a leading peer review journal.

The UK Food Standards Agency commissioned a review of all the literature relating to the nutritional quality of organic food. The review concluded: “On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organic and conventionally produced foodstuffs.”

As regards taste, the most comprehensive study carried out was at the University of Kansas, where clever experimental techniques allowed the researchers to vary the fertiliser type whilst growing the crops in identical microclimates. Trained taste panels could not distinguish between the organic and the conventionally grown foods.

Which brings us to pesticides. There should be no synthetic residues on organic food and that is a given. In contrast, conventionally grown foods may contain trace levels of pesticides. The Department of Agriculture conducts surveys of crops and completes analysis of the samples for residues of pesticides, and our unit in UCD conducts exposure analysis.

We find that the top 2.5 per cent of consumers of any crop will have pesticide intakes at levels between 0.1 per cent and 10 per cent of the safe exposure dose established by the World Health Organisation. Thus there is zero public health risk from pesticide use.

And before any organic enthusiast argues that accidents can happen, they can indeed, and they have happened in organic agriculture with acute health consequences such as the outbreak of E.coli infections in France last year associated with organic fenugreek. It is precisely because of the potential dangers to human health from accidents or negligence that we have such strong food regulatory structures.

Organic agriculture is commonly believed to be more environmentally friendly than conventional agriculture. However, a report commissioned by the UK department of the environment, food and rural affairs and completed by the University of Manchester concluded: “There is insufficient evidence available to state that organic agriculture overall would have less environmental impact than conventional agriculture.

“In particular, from the data we have identified organic agriculture poses its own environmental problems in the production of certain foods, either in terms of nutrient release to water or in terms of climate-change burden. There is no clear-cut answer to the question: which ‘trolley’ has the lowest environmental impact: the organic one or the conventional one.”

For example, organic wheat production requires less energy than conventionally farmed wheat but requires more land. On the other hand there is no difference between organically grown or conventionally grown potatoes and both require 40 per cent of the total energy for storage. This then raises the question of “food miles” that is driven by the “eat local” movement. Once again things are not so straightforward.

Two trays of apples sit side by side in a local Dublin supermarket. One comes from north Co Dublin and the other from New Zealand.

Intuitively, one imagines that the locally grown apples must have a lower carbon footprint. That, of course, depends on the time of year the comparison is made. The New Zealand apples were picked last week. In contrast, the local apples were picked last August, and have required both refrigeration and increased carbon dioxide to keep them ready for sale 11 months later. In terms of carbon footprint, the New Zealand apples win.

Without doubt the greatest fear and mistrust of the food industry is reserved for GM crops, but before looking at GM crops let us take a look at conventional plant breeding because all is not so obvious there.

In 1946 Herman Muller was awarded the Nobel prize in medicine for his discovery that X-rays could induce genetic mutations in crops and in insects, thus dramatically speeding up the task of breeding. His Nobel lecture explained his work: “Greatly simplified, X-ray irradiation, as also ionizing irradiation, could be likened in general to a shower of infinitely small but highly explosive grenades, which explode at different spots within the irradiated organism. The explosion itself tears the structure of the cell to pieces or disturbs its arrangement. If such an explosion happens to take place in or close to a gene, its structure, and therewith also its effect on the organism, may be changed.”

Under the auspices of the International Atomic Energy Agency (IAEA) in Vienna, the use of atomic radiation to induce mutations is a completely normal activity in plant breeding. The genetic changes lead to mostly useless and sterile mutants, but when you expose thousands of plants to this radiation a handful will show some desirable trait.

This technology has given us basmati rice, red grapefruits, barley for the whiskey industry and many thousands of crops, all listed on the IAEA website.

Modern genetic engineering alters the plant genome with great precision compared to the blunderbuss approach of radiation breeding where thousands more genes are altered. And yet one never hears of concerns that such radiation-bred crops will produce “Frankenfoods” or harm biodiversity or cause genetic drift, any of the other so-called horrors of modern GM.

The US National Academy of Science undertook a risk assessment of GM and radiation breeding and concluded thus: “Based on a detailed evaluation of the intended and unintended traits produced by the two approaches to crop improvement, the committee finds that the transgenic process presents no new categories of risk compared to conventional methods of crop improvement but that specific traits introduced by both approaches can pose unique risks.”

Organic food, slow food, local food and natural food are choices people make but their choices should never engender a fear among ordinary consumers that conventionally grown foods are in any way inferior.

The real issues with the modern food supply are nutritional in nature, with one billion overweight and one billion going hungry every day.


Prof Mike Gibney is director of the UCD Institute of Food and Health. He is the author of a recently published popular science book Something to chew on: Challenging controversies in food and health available at www.ucdpress.ie

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