The health benefits of some organic farm produce are not as great as scientists may expect, a new study suggests.
Researchers at the National Food Institute in Denmark said they have found new evidence that organically grown onions, carrots, and potatoes generally do not have higher levels of healthful antioxidants and related substances than vegetables grown with traditional fertilizers and pesticides.
Their study was published Wednesday by the American Association for the Advancement of Science (AAAS) on its website.
In the study, the scientists describe experiments in which they analyzed antioxidants termed "polyphenols" from onions, carrots and potatoes grown using conventional and organic methods.
They found no differences in polyphenol content for organic vs. traditional methods of growth.
"On the basis of the present study carried out under well controlled conditions, it cannot be concluded that organically grown onions, carrots, and potatoes generally have higher contents of health-promoting secondary metabolites in comparison with the conventionally cultivated ones," the study said.
With the demand for organically produced food increasing, there are many reasons to pay a premium for organic food products, said lead researcher Pia Knuthsen, a nutrition expert.
The most important reasons for the popularity of organic food products include improved animal welfare, environmental protection, better taste, and possible health benefits, he said.
However, he said, the health benefits of organic food consumption are still controversial and not considered scientifically well documented.
