Scientists say 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.
In the study, Pia Knuthsen and colleagues point out that there are many reasons to pay a premium for organic food products.
The most important reasons for the popularity of organic food products include improved animal welfare, environmental protection, better taste, and possible health benefits. However, the health benefits of organic food consumption are still controversial and not considered scientifically well documented.
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 report states.
Their study appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.