Jun 10, 2014

    Some myths about organic food and farming

    BUYING organic food is an exercise in personal virtue: You pay more to consume food that is healthier for you and less damaging to the environment because it is grown without artificial or toxic chemicals.

    This powerful perception, based more on belief than facts, goes a long way towards explaining why demand for organic products has grown so much.

    Organic sales have more than tripled in the past decade, to more than US$30 billion (S$38 billion) a year, while sales of conventional food products have dawdled along at an annual growth rate of about 2 per cent.

    There is just one huge problem: Neither of the main assumptions driving the growth of organic farming are grounded in science. In fact, there is evidence that organic farms produce as much, or more, pollution than normal farms and that organic products might actually contain more toxins than other foods.

    Like all farms, those that grow organic products rely on fertiliser. Often, organic farmers use animal manure rather than chemicals derived from petroleum or minerals.

    In one study of greenhouses in Israel, the use of manure led to much more nitrogen leaching into groundwater, compared with use of conventional fertilisation.

    A broader study of 12 different farm products in California found that in seven cases, those using conventional methods had lower greenhouse-gas emissions.

    A big reason for the difference? Conventional farming tends to be more efficient than organic farming, meaning fewer inputs are needed to generate the same amount of food.

    That hits on a critical issue for organic farming, as noted in a 2012 analysis of more than 100 studies of farming methods across Europe: Getting the same unit production from organic farming tended to lead to "higher ammonia emissions, nitrogen leaching and nitrous oxide emissions".

    And while organic farming tends to use less energy, it also leads to "higher land use, eutrophication potential" - that is the dead zones mentioned above - "and acidification potential per product unit".

    People need to realise that an organic label is not a straightforward guarantee of the most environmentally friendly product.

    Organic animal production also can cause problems. Unlike conventional farms, organic farms usually let animals wander around. No surprise that animals then do their business wherever nature calls. Rain, in turn, washes waste into local streams and rivers.

    Think of that next time you see free-range something on the menu. By comparison, conventional farms can (although they do not always) confine waste to covered areas. This prevents exposure to rain that causes polluted runoff.

    As for health benefits, the evidence suggests there is no distinguishable difference in nutritional value between organics and other food.

    Some types of organic production, notably the use of manure concentrations, actually lead to higher levels of toxins in food.

    One study in Belgium found that organically cultivated winter wheat had higher levels of lead and cadmium than conventionally grown wheat. The levels were below tolerable limits, and processing could have removed some of the contaminants.

    So are you worried now? You should not be. Buy what you like to eat whether it is organic or not - unless you are watching your food budget, in which case the choice is clear.