Organic food has no nutritional or health benefits over ordinary food, according to a major study published this week in the American Journal of Clinical Nutrition.

According to a Reuters news article, researchers from the London School of Hygiene & Tropical Medicine said consumers were paying higher prices for organic food because of its perceived health benefits, creating a global organic market worth an estimated $48 billion in 2007.

The researchers reviewed 52,471 articles and identified 162 studies dating back to 1958, with 137 on crops and 25 evaluating livestock products. Of those, they judged 55 were of satisfactory quality for their analysis. They determined that conventionally produced crops had a significantly higher content of nitrogen, and organically produced crops had a significantly higher content of phosphorus and higher titratable acidity. No evidence of a difference was detected for the remaining 8 of 11 crop nutrient categories analyzed. According to the article abstract, the more limited database on livestock products revealed no evidence of a difference in nutrient content between organically and conventionally produced livestock products.

The authors conclude that “On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods.”

Read the article from Reuters.

Read the abstract from the American Journal of Clinical Nutrition.