RODALE NEWS, EMMAUS, PA—It’s hard to find fault with the latest field trials showing that organically grown strawberries are more nutritious than their chemically grown counterparts. The study also shows that the soil in which the organic strawberries were grown is healthier.
THE DETAILS: The comprehensive experiment, led by John Reganold, PhD, Washington State University Regents professor of soil science, controlled for three important variables: The soil was the same, the varieties of strawberries were the same, the weather was the same. Reganold and his team grew three varieties of strawberries on 13 organic and 13 conventional fields that were side by side, just 25 to 50 feet apart.
It's a significant addition to the body of scientific literature comparing organic and chemical growing methods, says Reganold. "There is no study that represents reality as well as this one does," he says. "What makes it so strong is that we have so much data." About 150 studies have been done comparing other fruits and vegetables, but most have been criticized because the sample was too small, or because there were too many variables that may have influenced the results. Of the 150 published studies, only about 10 are considered scientifically valid. Of those 10, eight favor organic; two show no difference.
In Reganold’s studies, published in the peer-reviewed online journal PLoS, the experiments were repeated over a two-year period, and the strawberries were handled just as if they were going to a retail location. The taste and nutritional quality of the three varieties of strawberries were analyzed, and so was the soil in which they grew.
The organic strawberries were smaller but denser. They had almost 10 percent more vitamin C, and were almost 9 percent higher in antioxidants, two important reasons for eating them, since strawberries have the most concentrated levels of vitamin C and antioxidants in the diet. The organic berries were also lower in potassium and phosphorous than the conventional berries, but that should not take away from their superiority, since strawberries are not a significant source of potassium. (The best sources of potassium are bananas, root vegetables, melons, peaches, and avocados.) As for phosphorus, many Americans—notably those of us who drink cola beverages—get too much phosphorus in our diets, and that can lead to bone loss.
More sweet news: The research also suggests that choosing the superior nutrition of organic strawberries doesn't mean sacrificing flavor. In a blind tasting by a consumer panel, tasters judged the organic version of one strawberry variety, Diamante, as better-tasting than the chemically grown version. For the other two varieties, there was little or no difference in taste reported. Finally, the organic berries had less post-harvest fungal rot, (even though no synthetic chemical fungicides were used on them), and spoiled more slowly.
Published on: September 7, 2010