by Catherine Haug, September 7, 2012
Last week, the media (2,3,4) were all abuzz about a new study from a Stanford University Medical School team. They surveyed the global literature for “evidence of differences between the nutritional quality and safety of organic and conventional foods,” (1) and came to two major conclusions (1):
- “The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods.”
- “Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.”
What does this mean for us, the consumers? What does this mean for those of us who want to eat the most healthful diet? What does this mean for the health of our environment?
An expert’s analysis of the study
Charles Benbrook of the Center for Sustaining Agriculture and Natural Resources Washington State University recently penned an analysis of this study (1), showing its weaknesses, and important information it ignored. He concludes this was a poorly designed and executed study of the literature. He asserts that Organics DO provide more health benefits in nutritional quality and safety than non-organics, and provides strong references to prove his point. His analysis is a 12-page pdf file (1).
Here are a few of the points he makes (1):
- “The basic indicators used to compare the nutritional quality and safety of organic versus conventional food consistently understate the magnitude of the differences reported in high-?quality, contemporary peer-?reviewed literature.”
- “In its analysis the team does not tap extensive, high quality data from the USDA and Environmental Protection Agency (EPA) on pesticide residue levels… as well as a persuasive body of literature on the role of agricultural antibiotic use in triggering the creation of new antibiotic resistant strains of bacteria, and the genes conferring resistance.”
- The studies reviewed were not designed to provide the kind of information sought in the new study of them. “Very few studies are designed or conducted in a way that could isolate the impact or contribution of a switch to organic food from the many other factors that influence a given individual’s health. Studies capable of doing so would be very expensive, and to date, none have been carried out in the U.S. “
- “The Stanford team does not define empirically what it means by a food being ‘significantly more nutritious’ than another food.”
- He cites other, well-designed studies that DO show greater amounts of certain nutrients in Organics than in non-organics. These nutrients include Vitamin C, antioxidants, and phenolic acids. On the other hand, these studies show that non-organics are generally higher in other nutrients like vitamin A and protein than Organics.
- “An enormous body of evidence compiled by the EPA during the course of conducting pesticide dietary risk assessments shows that the number of high-?risk samples in any given year, for any given food, is driven by the presence of relatively high levels of the most toxic pesticides, rather than the absolute number of residues detected in the food.”
- How does one make a meaningful and quantifiable definition of ‘health risk?
What about the effects of pesticide contamination?
The NPR article (4) states:
“There was less pesticide contamination on organic produce. But does that matter? The authors of the new study say probably not. They found that the vast majority of conventionally grown food did not exceed allowable limits of pesticide residue set by federal regulations.”
Right off the bat I wonder, are the limits of pesticide residues set by federal regulations actually safe?
What about GMO?
Also the study did not consider that the GMO crops are more heavily treated with pesticides and herbicides than non-GMO crops. Nor did the study consider the negative health effects of GMO foods.
Our safest hedge against the GMO bet is Organics….
Effect of varieties within a species
Another important consideration has to do with the many varieties within a species. Generally, non-organic growers practice mono-culture, using varieties that can withstand a transportation across many miles and long time on the shelf. These varieties generally are lower in nutrient quality BECAUSE of the long span of time from harvest to consumption by the consumer, not to mention the potential for less nutrient quality at harvest because of the extent of hybridization.
On the other hand, Organic growers tend to plant heirloom (non-hybrid) varieties within a species. Some of these varieties might be lower in nutrient content and others might be higher. Yet the study typically only selected one variety within a species, so may not have selected the most nutritious one (4).
What about effects on the environment?
The study does not address per se the effect of organic vs non-organic agricultural practices upon the environment: our air, our water, our soil. Nor does it address the importance of supporting local growers who use organic methods (whether or not they are certified) on the health of our communities and local economy.
References:
- Initial Reflections on the Annals of Internal Medicine Paper “Are Organic Foods Safer and Healthier Than Conventional Alternatives? A Systematic Review” by Charles Benbrook
- New York Times: Stanford Scientists Cast Doubt on Advantages of Organic Meat and Produce
- Chicago Sun-Times: Organics not a healthier food choice, study finds
- NPR: Why Organic Food May Not Be Healthier For You