Organic tomatoes go on the defensive From a safety standpoint, there's no arguing that organic produce is worth the extra few cents supermarkets charge for it. As I told you last month, heavy exposure to pesticides -- which hang on for dear life through even the most thorough washing of commercially grown produce -- can increase the risk of brain cancer by as much as 29 percent. From a nutritional perspective, though, the case for organic fruits and vegetables has been a bit murkier. Until recently there just wasn't much evidence that organic produce is actually more nutritious than regular. But a study published a couple of months ago in the Journal of Agricultural & Food Chemistry found that organically grown tomatoes have more antioxidant-rich flavonoids than the commercially grown varieties. And not just a little more: The researchers found that organic tomatoes contained 79 percent more quercitin and a whopping 97 percent more kaempferol (see "What is…?" below for more information on kaempferol). That's almost double what you get in "regular" tomatoes! The study's authors theorized that over-fertilization was at the root of this discrepancy. The twist is that the plants that did get fertilized -- the conventionally grown tomatoes -- are the ones that had less nutritional value. Apparently, plants produce more flavonoids when they're not fertilized on a regular basis. As the non-fertilized soil gets depleted of its nutrients, the plant produces its own flavonoids to make up for what it's not getting from its environment. And the less fertile the soil becomes over time, the more flavonoids the plant produces. Essentially, plants have their own built-in defense mechanism to protect them from nutrient deficiency. We may not have the innate ability to correct our own deficiencies, but it's nice to know that we do have the tools necessary to fix them: vitamins, minerals, and other supplements combined with a diet rich in uber-nutritious organic foods. Sources:
"Are organic tomatoes more nutritious?" NutraIngredients (www.nutraingredients.com), 7/5/07
"Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes," Journal of Agricultural & Food Chemistry 2007; 55(15): 6,154-6,159 | 
