July 12, 2014
Organic Crops Found To Contain More Nutrients, Less Pesticide Residue
redOrbit Staff & Wire Reports - Your Universe Online
An in-depth comparison of the nutritional quality and safety of food production methods has revealed that organic crops contain more antioxidants, as well as fewer and less frequent pesticide-related residue.
Lead investigator Carlo Leifert, a professor at the Newcastle University School of Agriculture in the UK, and an international team of colleagues examined 343 peer-reviewed publications that compared the nutritional quality and safety of both organic and conventionally grown fruits, vegetables and grains.
The study authors conducted a meta-analysis of techniques to quantify differences between the two different types of food production, and most of the papers they reviewed looked at crops that had been grown in the same region using the same soil – reducing the amount of variables in terms of nutritional content and safety parameters.
Leifert’s team discovered there were multiple nutritional benefits associated with the methods used to produce crops. For instance, they said that a plant grown on a conventionally-managed field would typically be exposed to high levels of synthetic nitrogen, and would convert the additional resources into sugar and starch production.
When that occurs, the harvested portion of the plant is likely to contain lower amounts of antioxidants and other beneficial nutrients. In all, organic crops typically had between 18 percent and 69 percent higher antioxidant concentrations, and people who consume this type of food exclusively would receive an extra 20 percent to 40 percent of these nutrients – roughly equal to two additional daily servings of fruits or veggies.
In addition to learning there were nutritional and food safety benefits to organic farming. Leifert’s team also found that the quality and reliability of comparison studies on the topic had vastly improved over the past few years, leading to the discovery of significant differences in both categories that had gone undetected by earlier studies.
For instance, the meta-analysis included the results of a 2010 Washington State University project which compared conventional and organic strawberries grown in California. In a statement, the author of that study, John Reganold, said it was “impressive” and that the “major nutritional findings” were “similar to those reported” in his paper.
The study also found that, without being exposed to chemical pesticides, organic plants and crops tended to produce a greater amount of phenols and polyphenols in order to defend themselves from pest attacks. When consumed by people, phenols and polyphenols can help prevent coronary heart disease, stroke, some forms of cancer and other ailments that are at least partially the result of oxidative damage, the study authors explained.
Furthermore, pesticide residues were reportedly up to four times more likely in conventional foods than in organic ones, as the latter method does not allow synthetic pesticides to be applied to crops. Crops harvested from organically managed fields were not free of pesticides. They did occasionally contain residue, but at levels between 10-fold to 100-fold lower than the corresponding type of conventionally-grown fruits, vegetables or grains.
“In a surprising finding, the team concluded that conventional crops had roughly twice as much cadmium, a toxic heavy metal contaminant, as organic crops,” WSU explained. “The leading explanation is that certain fertilizers approved for use only on conventional farms somehow make cadmium more available to plant roots. A doubling of cadmium from food could push some individuals over safe daily intake levels.”
For the most part, however, WSU researcher and study co-author Charles Benbrook said that the study tells “a powerful story of how organic plant-based foods are nutritionally superior and deliver bona fide health benefits.” He added that he and his colleagues “learned valuable lessons from earlier reviews on this topic, and we benefited from the team’s remarkable breadth of scientific skills and experience.”
In a separate statement, Dr. Jessica Shade, Director of Science Programs for The Organic Center (TOC), said: “This is a ground-breaking study. This important research should help greatly to dispel consumer confusion about the benefits of organic. The nutritional differences between conventional and organic crops have always been a much debated topic. This significant study reevaluates the issue from a more inclusive, statistically accurate standpoint and strongly shows that organic fruits and vegetables have definite health benefits to conventionally grown products.”