A report published in the Annals of Internal Medicine on March 17 left meat eaters salivating. The meta-analysis of over 70 studies explored the comparative impact of saturated fat (found in meat, butter, and cheese) and unsaturated fat (found in vegetable oils, nuts, and fish) on heart disease. Challenging decades of conventional wisdom, the authors reported no clear correlation between levels of saturated fat and heart problems. Brashly, they concluded: "Current evidence does not clearly support guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats."
Food writers, who have long struggled with promoting meaty recipes without prescribing a heart attack on a plate, were wide-eyed with glee. New York Times columnist Mark Bittman wrote, “Butter is back, and when you’re looking for a few chunks of pork for a stew, you can resume searching for the best pieces — the ones with the most fat. Eventually, your friends will stop glaring at you as if you’re trying to kill them.” Christiane Northrup, writing in Huffington Post, practically urged readers to get thee to the nearest Burger King. “Think about it,” she wrote, “It's NOT the burger with cheese and bacon that's the issue. It's the ketchup, the bun, and the fries.” Michael Pollan, commenting on the Times coverage of the study, tweeted: “About time!”
A lot of "real" food is the seemingly pure and natural culmination of a chemically intensive process, one that we rarely hear about.
As a rule, one should be suspect when any nutrition study is widely celebrated. Sure enough, as so often happens, the other shoe quickly dropped on the saturated fat news. Within days of publication, critics of the study—as well as the researchers themselves—reported a slew of not insignificant errors. In one case the authors misinterpreted a study showing a strong correlation between unsaturated fats and positive heart health and, in another, they overlooked two critical studies on omega-6 fatty acids that presumably did not support their findings.
Scientists were unusually vocal in their critiques. The omissions, according to a New Zealand scientist, "demonstrate shoddy research and make one wonder whether there are more that haven't been detected." The authors of the study “have done a huge amount of damage,” Walter Willet, the chair of the nutrition department at the Harvard School of Public Health, told Science. Deeming the work “dangerous,” he called for a retraction.
Vocal critiques notwithstanding, the media blast touting this study cannot be undone. Willet noted as much, saying, "It is good that [the authors] fixed it for the record, but it has caused massive confusion and the public hasn't heard about the correction." A big problem for Willet is meta-studies more generally."It looks like a sweeping summary of all the data, so it gets a lot of attention,” he said, “but these days meta-analyses are often done by people who are not familiar with a field, who don't have the primary data or don't make the effort to get it."
Just as unfortunate as the apparently flawed meta-study was the quickness with which the food writers pushed it to the center of the media’s plate. Why such zeal? Why not wait until there was some vetting? In one sense, the urge to promote such a study is driven not so much by an inherent love of eating animals as a legitimate disdain for processed junk food. A study such as this one, although not about processed food per se, certainly offers a convenient basis to remind readers that heavily processed “food” parading as low-fat healthy alternatives to “real” food is bad news for the ticker. Typically, it is. So, perhaps the reasoning goes, any chance to clarify this point should be exploited in the interest of public health.
But still, aside from the disingenuousness of using a study on fat and heart health as grounds for condemning processed food, there’s also the dubious manner in which processed foods are condemned. Leading food writers never quite get around to explaining what exactly they mean by “processed” or “real” food. Bittman, who seems to think we can now eggs-and-bacon our way to heart health, evaluates a food’s integrity on the number of ingredients it contains. The longer the list the less real the food. This is not a bad rule of thumb, as far as it goes, but it’s also sort of like judging the quality of a library by the number of books it contains. Plus, if it's supplemental inputs that we’re concerned about, one could just as easily consult a farm-to-fork list of chemicals required to produce bacon and eggs and find himself wishing he’d paid better attention in chemistry class. A lot of “real” food, in other words, is the seemingly pure and natural culmination of a chemically intensive process, one that we rarely hear about. Get into the genetics behind what you eat, moreover, and things get unreal fast.
What I suspect the media endorsement of this flawed study is ultimately about is promoting the “eating like grandmother” agenda, an agenda that aims to heighten the appeal of the small local farm. This advice is standard foodie fare, combining a romantic notion of pre-industrialized agriculture with an anti-corporate ideology to promote threadbare notions such as eating local, buying organic, and, as Bittman endorsed it in his “Butter Is Back” piece, “avoid[ing] anything that didn’t exist 100 years ago.” These ideas might be seductive in their simplicity, but they’re rooted in soft and shifting sands, leaving consumers to confirm biases without necessarily improving their health or the quality of our food system.