Washington - Organically grown crops contain more healthy compounds than conventional crops, perhaps because they are not exposed to pesticides, American researchers reported on Friday.
Tests on organically and sustainably grown berries and corn showed they contain up to 58 percent more polyphenolics, compounds that act as antioxidants and may protect cells against damage that can lead to heart disease and cancer.
Organic food is grown without chemical pesticides or fertilizers. Sustainably grown food is grown without artificial pesticides.
"This really opens the door to more research in this area," said Alyson Mitchell, an assistant professor of food science at the University of California, Davis, who led the study.
Her team compared levels of total polyphenolics and ascorbic acid content in blackberries, strawberries and corn grown organically, sustainably or conventionally.
The team found that blackberries grown sustainably or organically and then frozen contained 50 percent to 58 percent more polyphenolics than conventionally grown crops from neighboring plots.
Sustainably grown frozen strawberries contained 19 percent more polyphenolics than conventional fruit.
Sustainably grown and organic produce also had more ascorbic acid, which the body converts to vitamin C, Mitchell's team reported in the Journal of Agricultural and Food Chemistry.
The polyphenolics in the organic crops were at levels seen in wild plants, Mitchell said, suggesting that plants treated with pesticides need to make less of the chemicals.
Plants make vitamins, polyphenolics and other antioxidants to protect themselves from dangers such as pests and drought.
Many studies show that eating plenty of fruits and vegetables can reduce the risk of heart disease, cancer and other disease. Polyphenolics are believed to be one reason.
"We know they're beneficial, but we don't know what types of polyphenolics are beneficial, or in what quantities," Mitchell said.