Are Organic Foods Better?
That Flawed Stanford Study By MARK BITTMAN
I tried to ignore the month-old “Stanford study.” I really did. It made so little sense that I thought it would have little impact. That was dumb of me, and I’m sorry. The study, which suggested — incredibly — that there is no “strong evidence that organic foods are significantly more nutritious than conventional foods,” caused as great an uproar as anything that has happened, food-wise, this year. (By comparison, the Alzheimer’s/diabetes link I wrote about last week was ignored.) That’s because headlines (and, of course, tweets) matter. The Stanford study was not only an exercise in misdirection, it was a headline generator. By providing “useful” and “counterintuitive” information about organic food, it played right into the hands of the news hungry while conveniently obscuring important features of organic agriculture. If I may play with metaphor for a moment, the study was like declaring guns no more dangerous than baseball bats when it comes to blunt-object head injuries. It was the equivalent of comparing milk and Elmer’s glue on the basis of whiteness. It did, in short, miss the point. Even Crystal Smith-Spangler, a Stanford co-author, perfectly captured the narrowness of the study when she said: “some believe that organic food is always healthier and more nutritious. We were a little surprised that we didn’t find that.” That’s because they didn’t look — or even worse, they ignored. In fact, the Stanford study — actually a meta-study, an analysis of more than 200 existing studies — does say that “consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.” Since that’s largely why people eat organic foods, what’s the big deal? Especially if we refer to common definitions of “nutritious” and point out that, in general, nutritious food promotes health and good condition. How can something that reduces your exposure to pesticides and antibiotic-resistant bacteria not be “more nutritious” than food that doesn’t? Because the study narrowly defines “nutritious” as containing more vitamins. Dr. Dena Bravata, the study’s senior author, conceded that there are other reasons why people opt for organic (the aforementioned pesticides and bacteria chief among them) but said that if the decision between buying organic or conventional food were based on nutrients, “there is not robust evidence to choose one or the other.” By which standard you can claim that, based on nutrients, Frosted Flakes are a better choice than an apple. But they’re not. And overlooking these key factors allows the authors to imply that there isn’t “robust” evidence to choose organic food over conventional. (Which for many people there is.) Under the convenient cover of helping consumers make informed choices, the study constructed a set of criteria that would easily allow them to cut “organic” down to size. Suspect conclusions derived from suspect studies are increasingly common. In the last couple of weeks: having a poor sense of smell might be linked to being a psychopath. People who read food labels are thinner. G.M.O.’s give rats tumors. (That one in particular violated many rules of both science and ethics.) Usually these “revelations” are of little more than passing interest, but they can sometimes be downright destructive. Susan Clark, the executive director of the Columbia Foundation, summed up the flaws of the Stanford approach perfectly in a letter to her colleagues: “The researchers started with a narrow set of assumptions and arrived at entirely predictable conclusions. Stanford should be ashamed of the lack of expertise about food and farming among the researchers, a low level of academic rigor in the study, its biased conclusions, and lack of transparency about the industry ties of the major researchers on the study. Normally we busy people would simply ignore another useless academic study, but this study was so aggressively spun by the PR masters that it requires a response.” When Clark says “aggressively spun by the PR masters,” this is what she means: a Google search for “Stanford Annals of Internal Medicine” gave me these six results in the top seven: Stanford Scientists Cast Doubt on Advantages of Organic Meat and Produce (The New York Times) Why Organic Food May Not Be Healthier for You (NPR) Organic food no more nutritious than non-organic, study finds (MSNBC) Organic Food Is No Healthier Than Conventional Food (U.S. News and World Report) Study Questions How Much Better Organic Food Is (Google via A.P.) Save Your Cash? Organic Food Is Not Healthier: Stanford U. (New York Daily News) Yet even within its narrow framework it appears the Stanford study was incorrect. Last year Kirsten Brandt, a researcher from Newcastle University, published a similar analysis of existing studies and wound up with the opposite result, concluding that organic foods are actually more nutritious. In combing through the Stanford study she’s not only noticed a critical error in properly identifying a class of nutrients, a spelling error indicative of biochemical incompetence (or at least an egregious oversight) that skewed one important result, but also that the researchers curiously excluded evaluating many nutrients that she found to be considerably higher in organic foods. Even the Web site of Stanford’s Freeman Spogli Institute for International Studies (which supported the research) features an article right above that about the new study that says “study confirms value of organic farming” and details how conventional agriculture is much more likely to contaminate drinking water with nitrates, which “can cause serious illness in humans, particularly small children.” What’s healthy and nutritious again? Like too many studies, the Stanford study dangerously isolates a finding from its larger context. It significantly plays down the disparity in pesticides (read Tom Philpott on this) and neglects to mention that 10,000 to 20,000 United States agricultural workers get a pesticide-poisoning diagnosis each year. And while the study concedes that “the risk for isolating bacteria resistant to three or more antibiotics was 33 percent higher among conventional chicken and pork than organic alternatives,” it apparently didn’t seek to explore how consuming antibiotic-resistant bacteria might be considered “non-nutritious.” Finally (I think) it turns out that Cargill (the largest privately held company in the United States) provides major financing for Freeman Spogli, and that’s inspired a petition to retract the findings.