Organic produce found to be higher in health-promoting compounds. (Environmental Intelligence).

Foods grown without pesticides contain substantially higher concentrations of antioxidants and other health-promoting compounds than crops produced with pesticides, according to a new study from the University of California at Davis (UCD). The study confirms a long-held suspicion among some nutritionists and agricultural scientists that heavy use of pesticides and chemical fertilizers in modern agriculture can disrupt the ability of crops to synthesize certain phytochemicals-compounds that have antioxidant properties and are associated with reduced risk for cancer, stroke, heart disease, and other illnesses.

Researchers tested corn, strawberries, and marionberries (a type of raspberry) for the presence of phenolic compounds, powerful antioxidants found in most fruits and vegetables. Phenolics include some flavinoids found in grapes and other red fruits and vegetables, and vitamin C (ascorbic acid) found in most citrus fruits. All produce came from the same farm in Oregon, which grew the crops under organic (no synthetic pesticides or fertilizers), sustainable (reduced or no synthetic pesticides), and conventional conditions, while keeping crop variety, soil type, and time of harvest consistent.

Sustainably grown corn contained 58 percent more phenolics than conventionally grown corn, and organic corn contained 56 percent more. Similar results were found for marionberries. Sustainably grown strawberries contained 19 percent more total phenolics than conventionally grown strawberries. (Organic samples were not available for strawberries.) This is the first study to show a correlation between growing technique and phytochemicals, according to lead author Alyson Mitchell, an assistant professor at the UCD's Department of Food Science and Technology.

"Lots of these compounds are synthesized to protect the plant from insects and disease," said Mitchell. "So if we're protecting the plant with pesticides, the plants are not going to waste the energy to produce them." On the other hand, organically and sustainably grown crops, raised with Little or no pesticides, must rely on their own defenses. Of course, conventional crops are also exposed to pest pressures, so Mitchell and her team plan to examine whether the use of agrochemicals may directly disrupt plant production of these beneficial compounds. Mitchell speculates that slightly higher level of phytochemicals in the sustainably grown samples compared to the organic samples may reflect more adequate nutrient availability, as all sustainable crops were treated with synthetic fertilizers.