Next Course in Organic Debate
Holzman, David C., Environmental Health Perspectives
With the Northern Hemisphere's peaking summer produce crop came a new iteration of the question of whether organic food is worth the extra expense. According to a review commissioned by the U.K. Food Standards Agency and published 29 July 2009 ahead of print in the September 2009 American Journal of Clinical Nutrition, organically grown food is no more nutritious man conventionally grown food. But organic proponents question the findings and also note that the health benefits of organic agriculture can go beyond nutrition.
The review authors identified more than 52,000 studies dating back to 1958 that compared organic and conventional foods. Of these, 55 studies were deemed of sufficient quality. None of the studies predate 1990--an important point, says first author Alan D. Dangour, a senior lecturer at the London School of Hygiene & Tropical Medicine, because one chief criticism of the review has been the fact that agriculture has changed markedly over the past 60 years.
Of 11 parameters examined, organic crops had significantly higher phosphorus content and titratable acidity (which is not a nutrient but a food processing metric) whereas conventional crops had higher nitrogen content. Differences in levels of vitamin C, phenolic compounds, magnesium, calcium, potassium, zinc, total soluble solids (mostly sugar), and copper were insignificant.
The results contradict a review published as the report New Evidence Confirms the Nutritional Superiority of Plant-Based Organic Foods in March 2008 by The Organic Center, a nonprofit food research outfit. This review found that total phenolics, vitamin E, vitamin C, quercetin, and total antioxidant capacity of organics exceeded that of conventionally grown produce--in the case of total antioxidant capacity, by 80%. Conventional products had higher levels of potassium, phosphorous, and total protein, all basic constituents of conventional fertilizers. Nutrition scientist Denis Lairon reported similar findings in a review published online 8 July 2009 ahead of print in Agronomy for Sustainable Development.
Charles Benbrook, The Organic Center's chief scientist and coauthor of the New Evidence report, criticizes the U.K. review for not requiring the individual studies to have used the same cultivars on organic and conventional plots. …