Organic produce conferred greater health benefits than conventionally grown fruits and vegetables, a study of fruit flies showed.
Researchers at Southern Methodist University concluded that fruit flies fed a diet labeled "organic" performed better on health measures than the control, with greater fertility rates too. Organic potatoes, raisins and soy all conferred associations with significantly longer lifespans, with no difference observed between organic and conventional bananas. Moreover, flies raised on organic versions of all four foods experienced greater fertility rates.
However, organic raisins led to poorer health outcomes than those raised conventionally, with fruit flies experiencing greater stress and also mortality under "starvation resistance."
Researchers bought all of the food at the same Texas Whole Foods store, producing results that suggest organic foods be judged less on a holistic basis and by item. While these findings are certainly intriguing, what we now need to determine is why the flies on the organic diets did better, especially since not all organic diets we tested provided the same positive health outcomes," said Johannes H. Bauer, the lead investigator in the study.
Indeed, the findings fly in the face of Stanford University researchers who last year reported no additional nutritional benefit to organic foods.
"There isn't much difference between organic and conventional foods, if you're an adult and making a decision based solely on your health," said Dr. Dena Bravata, who led the study, which was published in September in the Annals of Internal Medicine. In that study, researchers analyzed 237 academic papers on the subject, including 17 studies of populations consuming organic and conventional diets, with 223 comparing the nutrient levels or the bacterial, fungal or pesticide contamination of various products - including animal products - grown by either method.
Some of these studies went beyond fruit flies to follow humans, though no human study persisted longer than two years, with some as short as two days.
In analyzing data on produce, the Stanford researchers had found little discrepancy in health benefits between the two food categories, with no consistent difference in the vitamin and nutrient content, save phosphorus - a finding that lacked clinical significance, they said, given that few people lack for sufficient levels of the nutrient.
Stanford researchers said organic produce might confer the benefit of limiting exposure to pesticides, without value-added nutrition.
Though any producer may label produce as "organic," major producers - grossing more than $5,000 per year - must comply with government standards to carry the USDA organic seal.