The organic sector has reacted with a mixture of fury and disbelief to a UK Food Standards Agency report declaring organic food and ingredients are no healthier than their conventional counterparts.
The FSA, which is the UK's food industry regulator, said an independent review of scientific evidence showed there were that there were "no important differences in the nutrition content, or any additional health benefits, of organic food when compared with conventionally produced food."
The study, described as a "systematic review of literature," was carried out by the London School of Hygiene and Tropical Medicine (LSHTM). Researchers reviewed papers published over the past 50 years that related to the nutrient content and health differences between organic and conventional food. The FSA said the review was "the most comprehensive study in this area that has been carried out to date."
"This study does not mean that people should not eat organic food," said Gill Fine, FSA director of consumer choice and dietary health. "What it shows is that there is little, if any, nutritional difference between organic and conventionally produced food and that there is no evidence of additional health benefits from eating organic food."
But the review was criticised by the Soil Association, the UK-based organic certification and campaign body. Peter Melchett, policy director, said: "We are disappointed in the conclusions the researchers have reached. The review rejected almost all of the existing studies of comparisons between organic and non-organic nutritional differences. This was because these studies did not meet particular criteria fixed by the London School of Hygiene and Tropical Medicine, which carried out the review."
Melchett said that despite dismissing them as "not important", researchers had in fact acknowledged in the report that there were differences between organic and no organic food. The mean positive difference between the following nutrients, when comparing organic to non-organic food, was found in the FSA study to be:
- Protein 12.7%
- Beta-carotene 53.6%
- Flavonoids 38.4%
- Copper 8.3%
- Magnesium 7.1%
- Phosphorous 6%
- Potassium 2.5%
- Sodium 8.7%
- Sulphur 10.5%
- Zinc 11.3%
- Phenolic compounds 13.2%
But Alan Dangour, the principal author of the paper, said: "A small number of differences in nutrient content were found to exist between organically and conventionally produced crops and livestock, but these are unlikely to be of any public health relevance. Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority."
The Soil Association also criticised the FSA for not including the results of a European Union-funded study involving 31 research and university institutes and the publication of more than 100 scientific papers, which ended in April this year. The programme, it said, had concluded that levels of a range of nutritionally desirable compounds were shown to be higher in organic crops, while levels of nutritionally undesirable compounds were shown to be lower.
The FSA's report also drew criticism from across the Atlantic. In a detailed analysis of the review, Charles Benbrook, chief scientist at the American pro-organic organisation The Organic Center wrote: "The London team downplayed positive findings in favour of organic food. In several instances, their analysis showed that organic foods tend to be more nutrient dense than conventional foods. Plus, their study omitted measures of some important nutrients, including total antioxidant capacity.
"It also lacked quality controls contained in a competing study released in 2008 by The Organic Center. Last, the FSA-funded team also used data from very old studies assessing nutrient levels in plant varieties that are no longer on the market."
Read Benbrook's full analysis at http://www.organic-center.org/about.mission.html)
A paper reporting the results of the FSA review of nutritional differences has been peer-reviewed and published in the American Journal of Clinical Nutrition: Nutritional quality of organic foods: a systematic review; Alan D Dangour, Sakhi K Dodhia, Arabella Hayter, Elizabeth Allen, Karen Lock and Ricardo Uauy; Am J Clin Nutr (July 29, 2009). doi:10.3945/ajcn.2009.28041