England—Organic crops and the foods made from them have significantly higher amounts of certain antioxidants, less frequent occurences of pesticide residue and lower levels of a toxic heavy metal than conventionally grown crops, according to the findings of a recent report. The Organic Trade Association (OTA) calls it a landmark study, and one that should settle the debate about the benefits of organic.

The study was led by researchers at Newcastle University, and consisted of an analysis of 343 peer-reviewed publications that compared organic and non-organic crops and crop-based foods. The amounts of several important antioxidants, such as stilbenes, phenolic acids and anthocyanins, were found to be superior in organic crops and food, up to 69% higher in the case of flavanones. The authors noted that these compounds have often been linked to reduced risk of chronic diseases, including heart and neurodegenerative diseases as well as some cancers. Differences in some vitamins and minerals were also found between the two types of crops.

Pesticide residue was four times more likely to be found on conventional crops than organic. There are also significantly higher concentrations of the toxic metal cadmium in conventional crops, according to the study. The higher antioxidant and lower cadmium concentrations in organic food may be linked to specific farming practices used by organic growers, including the avoidance of certain types of fertilizers. The overall results of the study, the researchers noted, apply across different agricultural production seasons and geographical regions.

This study may represent an improvement over earlier studies with similar designs, due to a larger and more up-to-date pool of research. A 2012 study out of Stanford, which concluded there was minimal difference between organic and conventional crops, analyzed around 200 research papers. A 2009 study out of the United Kingdom that found no benefits for organic analyzed only 46 publications, compared with the Newcastle study’s analysis of 343 publications, with 100 from the last five years.

Charles Benbrook, one of the new study’s authors and a research professor at the Center for Sustaining Agriculture and Natural Resources at Washington State University, said in a statement, “Our results are highly relevant and significant, and will help consumers sort through the often conflicting information on the nutrition of organic and conventional plant-based foods.”

The study appeared in July in the British Journal of Nutrition.

Published in WholeFoods Magazine, September 2014 (online 7/15/14)