Jacob Sullum has good stuff on government regulation of kosher food, and organic food:

The preference for organic food, like the preference for kosher food, is essentially religious, based on faith rather than science. There is no good evidence, for example, that the pesticide residues organic produce buyers are so keen to avoid pose a significant health risk....The national standards require access to outdoor recreation, although the connection to organicalness is hazy. Likewise, it's not obvious why genetically modified ingredients or irradiation to kill parasites should render food nonorganic.