Findings published in the Journal of Agricultural and Food Chemistry add to the on-going debate over whether organically grown produce is more nutritious than conventionally grown produce. A report published in March 2008 by the Organic Center at America’s Organic Trade Association argued that organic produce is 25 per cent more nutritious than conventional foodstuffs.
However, these claims were countered by Joseph Rosen, emeritus professor at Rutgers University and scientific advisor to the American Council on Science and Health (ACSH) who said the data was selective, and that, when recalculated, the data used in the original report showed that conventional products are actually 2 per cent more nutritious than organic varieties.
“In the present study the organically produced apples displayed a higher phytochemical concentration and a higher antioxidant capacity than conventionally produced apples,” wrote the researchers, led by Bernhard Watzl from the Federal Research Institute of Nutrition and Food in Karlsruhe.
“However, it remains unclear whether these minor differences caused by the production method are of nutritional relevance.”
Study details
Watzl and his co-workers compared the polyphenol content and antioxidant capacity of Golden Delicious apples grown under organic and conventional conditions over a three year period (2004-2006).
According to their findings, in 2005 and 2006 the antioxidant capacity was 15 per cent higher in the organic fruit than the conventionally produced fruits. Organic apples grown in 2005 also had a higher polyphenol concentration, said the researchers.
On the other hand, no differences between the organic and conventional fruit were observed when the researchers compared fruit from 2004 and 2006.
“The organically grown apples showed a tendency of higher phytochemical concentrations compared to the conventionally produced apples (10 per cent), resulting in a 12 per cent higher antioxidant capacity in the course of three years,” wrote the researchers.
No end in sight?
A recent review, published in the journal Nutrition Bulletin (June 2007, Vol. 32, pp. 104-110) and authored by Claire Williamson from the British Nutrition Foundation, stated that the overall body of science does not support the view that organic food is more nutritious than conventionally grown food.
"Organic farming represents a sustainable method of agriculture that avoids the use of artificial fertilisers and pesticides and makes use of crop rotation and good animal husbandry to control pests and diseases," wrote Williamson. "From a nutritional perspective, there is currently not enough evidence to recommend organic foods over conventionally produced foods."
Source: Journal of Agricultural and Food Chemistry Published online ahead of print, 23 April 2009, doi: 10.1021/jf803961f“Three-Year Comparison of the Polyphenol Contents and Antioxidant Capacities in Organically and Conventionally Produced Apples (Malus domestica Bork. Cultivar `Golden Delicious')” Authors: B.A. Stracke, C.E. Rfer, F.P. Weibel, A. Bub, B. Watzl