Are organic veggies are more nutritious than conventional?
May 29, 2008 § 1 Comment
Well if you’re addicted to your local public radio station, then this is “old news,” but if you missed the story on NPR this morning about Stephen Kaffka’s research at UC Davis, have no fear, NPR has audio archives and you can listen at your leisure.
The story was interesting to me because it discussed what aspects of organic produce makes them more nutritious, and the biological processes that impact the nutritional value of the veggies (specifically tomatoes). When I was at the Food and Medicine Culture at the Neighborhood Level meeting, both Charlotte Anthony and Nick Routledge both spoke about their personal experiences helping people who were ill to heal using organic, local, seasonal food.
Harry McCormick of the Ten Rivers Food Web also spoke briefly about the higher nutritional value of food in an interview on OPB’s new weekly radio show, Think Out Loud (which is also archived for audio streaming). Also, the Organic trade association has published more information on the nutritional superiority of organic produce.
The science behind all of this is, again, the most interesting part to me. Flavanoids are the key, with their antioxidant activities… and well, we should all be aware by now that antioxidants have anticancer properties. In the NPR story, Kaffka explained how the flavanoids can exist in an organically-grown tomato that might not exist in a conventionally-grown plant:
On Kaffka’s plot, the conventionally grown tomatoes get commercial fertilizer made with soluble inorganic nitrogen, a form of nitrogen the plants can take up very quickly. The organic tomatoes get nitrogen from manure and composted cover crops. These organic materials have to be broken down by the microbes in the soil before the nitrogen is released to the plants.
“It takes time,” Kaffka says, and the nitrogen is “not instantaneously available.”
With limited nitrogen, the organic plants may grow slower, says Alyson Mitchell, a food chemist at UC Davis. When this happens, she says, the plant “has more time to allocate its resources toward making secondary plant metabolites” such as flavonoids.
Something so seemingly simple as how the plant processes the fertilizer can make a big difference in what the ultimate food product provides to us for our consumption. Beyond the simple lack of petroleum-based chemical residues on our food, the food itself may just be healthier.