Organic Food Doubts

A study published in the Annals of Internal Medicine on 4 Sept 2012 casts doubt on the organic food movement.

Data Synthesis: 17 studies in humans and 223 studies of nutrient and contaminant levels in foods met inclusion criteria. Only 3 of the human studies examined clinical outcomes, finding no significant differences between populations by food type for allergic outcomes (eczema, wheeze, atopic sensitization) or symptomatic Campylobacter infection. Two studies reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets, but studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences. All estimates of differences in nutrient and contaminant levels in foods were highly heterogeneous except for the estimate for phosphorus; phosphorus levels were significantly higher than in conventional produce, although this difference is not clinically significant. The risk for contamination with detectable pesticide residues was lower among organic than conventional produce (risk difference, 30% [CI, −37% to −23%]), but differences in risk for exceeding maximum allowed limits were small. Escherichia coli contamination risk did not differ between organic and conventional produce. Bacterial contamination of retail chicken and pork was common but unrelated to farming method. However, the risk for isolating bacteria resistant to 3 or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33% [CI, 21% to 45%]).

Conclusion: 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.

The New York Times quickly wrote, Stanford Scientists Cast Doubt on Advantages of Organic Meat and Produce:

Stanford University scientists have weighed in on the “maybe not” side of the debate after an extensive examination of four decades of research comparing organic and conventional foods.

They concluded that fruits and vegetables labeled organic were, on average, no more nutritious than their conventional counterparts, which tend to be far less expensive. Nor were they any less likely to be contaminated by dangerous bacteria like E. coli.

The NYT article admitted that organics probably had significantly less residue from pesticides, but in Scientific American, Christie Wilcox attacked that justification with Are lower pesticide residues a good reason to buy organic? Probably not.

A lot of organic supporters are up in arms about the recent Stanford study that found no nutritional benefit to organic foods. Stanford missed the point, they say—it’s not about what organic foods have in them, it’s what they don’t. After all, avoidance of pesticide residues is the #1 reason why people buy organic foods.

But as a lot of SA commenters noted, you can’t distill preference for organic to any one issue. Traditional farmers Agribusinessmen insist that organic farming is a chimaera, and that fossil-fuel-based mechanical farming is the only way to provide all the food that the world needs. The word “organic” is probably as abused as “user-friendly” or “green” or “new and improved,” but a 2007 Treehugger article does offer a definition:

In agriculture, this means that crops were grown without the use of conventional pesticides, artificial fertilizers or sewage sludge, and that they were processed without food additives (like chemical preservatives). When it comes to animals, they must be reared without the routine use of antibiotics and growth hormones and fed a diet of organic foods. In most countries, organic produce must not be genetically modified.

The holistic argument is more that using natural pesticides and fertilizers is better for the soil than that an individual bunch of grapes is safer for the shopper. Even if they don’t stay on the food, all those unnatural pesticides and fertilizers end up somewhere. Of course some Madison Avenue types are throwing the word organic around, but ideally, organic farming is supposed to be a sustainable food system that requires less fossil-fuel energy and that leaves less chemical byproducts behind.

On a personal note, my wife and I do notice a difference in produce from Whole Foods, Trader Joe’s and some farmer’s markets compared to ordinary supermarkets. For one thing the organic produce doesn’t rot a day after you bring it home. We simply won’t buy produce at some markets anymore. For another, it does taste better.