Fans of eating organic have always believed that organic fruits and vegetables packed a bigger nutritional punch than conventionally grown produce. ¶ But until pretty recently, hard scientific evidence has been lacking.
Studies that seemed to prove the theory often turned out to be poorly designed -- the organic and conventional crops weren't grown in the same area or weren't the same variety, for example. Or the samples were too small, the studies too short or they were flawed in some other way, according to food chemist Alyson Mitchell, an associate professor in the Department of Food, Science and Technology at the University of California-Davis.
Mitchell says it was just a few years ago that her own studies, which found higher nutrient levels in organic crops, were dismissed as nothing more than wishful thinking, no matter how well done the science was.
Now, though, the scientific pendulum is swinging. It seems that there are frequent headlines from university researchers around the world who have shown that organic tomatoes, corn or some other fruits and vegetables contain more nutrients, especially when it comes to vitamin C and other antioxidants.
"There's definitely a trend," Mitchell says.
Just this past year, three European studies have reported the benefits of organic crops, including peaches in France and apples in Poland.
The biggest was a four-year European Union-funded study of organic and conventional crops grown in side-by-side plots on 725 acres near Newcastle University, in the United Kingdom. The study showed levels of antioxidants 20 to 40 percent higher in organic wheat, tomatoes, potatoes, cabbage and lettuce, according to news reports.
Also making headlines was a 10-year study by a UC Davis team led by Mitchell, which looked at dried tomato samples collected over 10 years from side-by-side organic and conventionally farmed plots just west of the university. The results, published in the Journal of Agricultural Food Chemistry, were dramatic: The organic tomatoes contained 79 percent more of one antioxidant, and 97 percent more of another.