This is something I’ve believed for a while and some limited research has confirmed–that organic produce contains more nutrients than that grown conventionally. But a fairly new, well-designed, long term study called the U.C. Davis Long-Term Research on Agricultural Systems project is demonstrating this as well.
In 1993, researchers at the University of California at Davis set aside 10 fields in Sacramento Valley to compare organic vs. conventional farming methods. This study was unique in that the conventional and organic produce were grown in the same area, in the same climate, and at the same time. This study is also unique in that it’s projected to run 100 years. Just last year, results were published that compared conventional and organic tomatoes over the course of 10 years. “We’re seeing remarkable differences, certainly more significant than we expected,” says Alyson Mitchell, PhD, a U.C. Davis food chemist. Organic tomatoes consistently have higher levels of antioxidants like vitamin C and flavanoids. In fact, organic tomatoes have 97% more kaempferol and 79% more quercetin (both are types of flavanoids).
Tomatoes aren’t the only produce to demonstrate this. Organic kiwis, corn, marionberries, strawberries, potatoes, and grapefruit have been shown to have more nutrients than their conventional counterparts. This shouldn’t be too surprising as organic produce has to develop more nutrients like antioxidants to fend itself against pests. Organic produce also doesn’t grow as fast as conventional produce (which is blasted with nitrogen, causing it to grow quickly and results in what many farmers seem to value most–higher yield) and the slower development and deeper roots means that the produce can soak up more nutrients before making it to your plate. Combine this with less pesticide residues on produce, more sustainable agriculture, and less chemical exposures to farmers and their families and it’s clear that you should at least consider adding more organic foods to your diet.
I’ve posted this before, but it’s worth repeating. The following vegetables and fruits have been found to contain the highest pesticide residues so if you’re going to buy organic, these are some of the most important organic foods to purchase:
- apples
- bell peppers
- celery
- cherries
- imported grapes
- lettuce
- nectarines
- peaches
- pears
- potatoes
- spinach
- strawberries
For more on this, see the article “A Growing Trend” in the August 2008 issue of Cooking Light Magazine.
