Organically grown food is no more nutritious than conventionally grown food when it comes to the amount of certain important nutrients, according to a new review of published studies.

“We wanted to answer the question, ‘Is there any evidence that organic food is nutritionally superior to conventionally grown food?'” says the study’s lead author, Alan D. Dangour, PhD, a public health nutritionist at the London School of Hygiene & Tropical Medicine. “The answer is no. Organic food is not nutritionally superior to conventional food.”

The conclusions of the review, published in the American Journal of Clinical Nutrition, drew strong disagreement from U.S.-based food researchers.

The global market for organic foods is estimated to be about $48 billion annually, according to the London researchers. Organic foods are produced under standards that control the use of chemicals in crop production and medicine in animal production, among other regulations.

Organic vs. Conventional Foods: Review

Dangour and his colleagues searched for studies comparing organic and conventionally grown food from January 1958 to February 2008.