A superb article in the Australian popular science magazine Cosmos debunks the organic food and farming craze. On claims that organic is more nutritious, the article notes:
A comprehensive review of some 400 scientific papers on the health impacts of organic foods, published by Faidon Magkos and colleagues in 2006 in the journal Critical Reviews in Food Science and Nutrition, concluded there was no evidence that eating organic food was healthier.
Even if it can't be proved that eating organic is healthier, advocates claim it is nutritionally superior. Some studies, especially those reported by the organic farming advocate group, the British Soil Association, show that organic produce has a higher content of vitamin C, minerals and anti-oxidants such as flavonols, polyphenols, lycopene and resveratrol.
However, some of the compounds present at higher levels in organic food are actually natural pesticides. According to Bruce Ames, a variety of insect-resistant celery had to be taken off the U.S. market in the late 1980s because its psoralen levels were eight times higher than normal and caused a rash in people who handled it. There was a similar story with a naturally pest-resistant potato variety that ended up being acutely toxic because of its high levels of solanine and chaconine – natural toxins that block nerve transmission and cause cancer in rats. Organic farmers who rely on 'naturally resistant' plant varieties may also be producing plants with high levels of 'natural' toxins. And in this case, 'natural' is not likely to mean better. Think of Abraham Lincoln's poor mother, who died after drinking the milk of a free-range cow that had grazed on a snakeroot plant.
Regardless of how it is grown, the nutritional content of fruit and vegetables is more likely to be affected by freshness or varietal differences. One study reported by Magkos tried to narrow things down by growing the same variety of plums in adjacent fields, with one using organic and the other conventional methods: the conventionally grown plums contained 38 per cent more of the potentially beneficial polyphenol compounds than the organically grown ones did.
What about claims for sustainability? With regard to preserving topsoil, no-till farming using genetically modified crops wins hands down. To wit:
An 11-year farming experiment by the U.S. Department of Agriculture in Beltsville, Maryland, compared crops grown three ways: conventional tillage, organic methods, or no-till. Compared to the conventional tilled plot, the organic plot was likely to hang on to 30 per cent more soil. But compared to the organic plot, the no-till plot hung on to 80 per cent more soil.
What about the alleged health dangers of synthetic pesticides?
If chemical pesticides are hazardous to health, then farm workers should be most affected. The results of a 13-year study of nearly 90,000 farmers and their families in Iowa and North Carolina — the Agricultural Health Study – suggests we really don't have much to worry about. These people were exposed to higher doses of agricultural chemicals because of their proximity to spraying, and 65 per cent of them had personally spent more than 10 years applying pesticides. If any group of people were going to show a link between pesticide use and cancer, it would be them. They didn't.
A preliminary report published in 2004 showed that, compared to the normal population, their rates of cancer were actually lower. And they did not show any increased rate of brain-damaging diseases like Parkinson's. There was one exception: prostate cancer. This seemed to be linked to farmers using a particular fungicide called methyl bromide, which is now in the process of being phased out. According to James Felton, of the Biosciences Directorate of the Lawrence Livermore National Laboratory in California, who also chairs the study, "The bottom line is the results are coming out surprisingly negative. It's telling us that most of the chemicals we use today are not causing cancer or other disease."
Health of the planet and protecting nature?
...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.
Yields?
...the poor yield of organic farming means that food production would be a major problem. In Australia, for instance, organic farming yields 50 per cent or less per square kilometre because of pest problems and phosphate-depleted soils. (Phosphate is locked away in the ancient clays; conventional farmers help themselves to highly soluble chemically-made superphosphate. Organic farmers can't use a chemical, so they use poorly soluble rock phosphate.)
One critical point to note is that conventional farming using genetically modified crops has been reducing its effects on the natural world over time using the findings of science. Since organic is an ideology, its ability use of scientific findings to reduce its impact on the natural world is heavily constrained.
Look folks, eat all the organic food you want. Just don't be fooled into thinking that you're doing something good for your health or for the health of the planet. You're not.
Whole Cosmos article here.
Some of my own reporting in 2002 on organic alchemy here.