Stanford Analysis of Organic vs Conventional Foods – Well Done, Poorly Spun

A  Stanford University meta-analysis  comparing the health effects of organic to non-organic food has concluded that organic meat and produce, while not necessarily more nutritious than conventionally raised food, does harbor less antibiotic resistant bacteria and less pesticide residue. Pesticide levels are also lower in children consuming food from organic vs conventional sources.

[The researchers reviewed]7 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%].]

The researchers also found less fungal toxin contamination in organics and higher levels of Omega 3 fatty acids in organic dairy.

This is all  important information for consumers who want to lessen their family’s exposure to pesticides, some of which can be endocrine disruptors and have been linked to cancer.  It also supports organic claims as to the superior fatty acid content of milk and poultry.

Poorly Spun

And yet, here’s the way Stanford themselves pitched their research to the media –

Little evidence of health benefits from organic foods, Stanford study finds
BY MICHELLE BRANDT

Crystal Smith-Spangler and her colleagues reviewed many of the studies comparing organic and conventionally grown food, and found little evidence that organic foods are more nutritious.

You’re in the supermarket eyeing a basket of sweet, juicy plums. You reach for the conventionally grown stone fruit, then decide to spring the extra $1/pound for its organic cousin. You figure you’ve just made the healthier decision by choosing the organic product — but new findings from Stanford University cast some doubt on your thinking.

“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 Dena Bravata, MD, MS, the senior author of a paper comparing the nutrition of organic and non-organic foods, published in the Sept. 4 issue of Annals of Internal Medicine.

Huh? Exposure to pesticides and antibiotic resistant bacteria is not a factor to be considered in making buying choices based on your health? Omega 3 fatty acids are not important?  Says who?

The researchers  pointed out that they found only 17 human studies, too little to really base any long term recommendations, hence the “little evidence”. But there is “little evidence” because a hypothesis has been disputed, and “little evidence” because the volume of data is too small on which to base conclusions. The latter is clearly the case here, but the headline makes it appear to be the former.

The authors also point out that despite differences in pesticide exposure, most exposure, even in conventionally grown produce, was below government limits. But that’s not the point, is it? Organic proponents think government limits are too high in the first place, so this is not reassuring to them, or informative to the public.

And note also that Bravata was careful to say “If you’re an adult” – I would assume that means if you’re feeding a child, you may want to think differently.

My conclusions on the study

I’d say this study pretty much supports the claims that organic producers are making when it comes to the issues most important to consumers who choose organic food sources.

The media is all over this one

Headlines range from ” Stanford Scientists Cast Doubt on Advantages of Organic Meat and Produce” (NY Times) to” Organic Food Has Little Health Impact”   (Fox News ) and “Organic Food is not healther than conventional produce” (Huff Post).  Reuters actually had a more accurate headline “Organic food no more nutritious than conventionally non-organic” , which still is misleading in that it ignores the pesticide data, which is actually the reason most folks prefer organic.

I say ignore the headlines and read the study yourself. See what conclusions you come to, and buy accordingly.

_______________________________________________________________________________________

Essential Reading

• Mark Bittman – Eating Food that’s Better for you, organic or not.
• Michael Pollan –  Resource list and Much more.
• Tara Parker-Pope: – Five Easy Ways to Go Organic
• Environmental Working Group – Clean 15 vs the Dirty Dozen. Spend your precious produce dollars where they will benefit you most.