Anticipated Reversals

 The most recent episode of the Omnibus Project podcast—of which I've been a devoted listener since its inception—focused on the shifting fortunes of the "Food Pyramid." Remember that thing? Those of us who went to school in the '90s no doubt have some memory of this fictional edifice. We surely recall that the base of the image was always a hefty block of grain, flour, and starch; and that, higher up—as the shape narrowed—one could find smaller helpings of meat, poultry, dairy, fruits and vegetables. 

The evolution of nutrition science in the years since has not been kind to the Food Pyramid. Most of us have probably noted that today's dietary advice is almost the exact inverse of the pyramid's implied recommendations. Instead of loading up on carbohydrates—we now are told—one ought to consume proteins. Far from being the bedrock of any healthy diet, sugar-rich bread products are now seen as the cause of all our problems. The pyramid has been flipped on its head!

The "Food Pyramid" episode of the Omnibus thus forms a sort of trilogy with two earlier episodes of the podcast—"Olestra" and "A Glass of Red Wine With Dinner"—that similarly explored areas of health science that have pulled a complete 180-degree turn in the course of our lifetimes. We used to be told that eating fatty foods was the cause of obesity, and that we would lose weight if we substituted these with fat-free (but sugary) alternatives. Now, we are told the opposite. 

Likewise with alcohol. An emerging consensus among researchers these days holds that alcohol is even worse for one's health than previously believed. Yet I grew up in a world in which moderate drinking was encouraged as a health benefit. A "glass of red wine with dinner" was prescribed as the key to heart health. And, like so much dietary advice, it even had a veneer of homeopathic pseudo-plausibility to recommend it: wine looked like blood, after all, and—after drinking it—one could feel one's heart racing faster. 

The lesson from such examples surely should not be to disregard the medical consensus of the age. One hopes that, in the course of these pendulum swings, the weight of scientific opinion is eventually converging toward an equilibrium point, located somewhere proximate to the truth. There are oscillations in scientific opinion, then—and still more in popular science, as it is digested and packaged for us, oftentimes by interested parties—but the arcs hopefully become smaller over time. 

Still, these examples do underscore the vanity of taking any one current health bromide as a fixed and final truth. As Jonathan Swift observed, there are modes and styles in the natural sciences that shift as quickly in that cultural domain as do they in any other. "[N]ew systems of nature were but new fashions, which would vary in every age," as a character observes in Gulliver's Travels. Alcohol was in; now it is out. Grains and starches were in; now they are on the index of prohibited foods. 

Alfred Jarry's 1902 satirical novel The Supermale even manages to forecast such a fate for alcohol. The turn of the twentieth century, much like our own age, was after all a time of various health fads. One of the most powerful lobbying and advocacy groups of the era was the temperance movement—the teetotalers and prohibitionists. Jarry, however, predicted that the then-consensus on the evils of alcohol would be as short-lived as every other dietary fashion. Indeed, he forecasts it would eventually be inverted. 

Speaking from the imaginary standpoint of 1920—still two decades in the future, at the time Jarry was writing, he says: "by an anticipated reversal of scientific fashion, it was proclaimed that the only hygienic beverage was pure alcohol" (Wright/Gladstone trans.) And indeed, we lived to see it. It was many decades after Jarry's time, but scientists eventually declared that moderate drinking was in fact good for the heart. And we have seen since yet another "anticipated reversal of scientific fashion" in turn. 

Jarry's novel—like his other, even stranger work, The Exploits and Opinions of Dr. Faustroll—fits broadly into the category of the Menippean satire, within Northrop Frye's typology of literary genres. That is to say, these books' chief object of ridicule is the pretension of the crank scientist and the quack physician. Gulliver's Travels, not coincidentally, is another canonical example of the type. Each book derives its richest comedy from displaying the vanity of the human sciences. 

And indeed, the rate at which the "scientific" advice we are given on healthy living alters—not only to the point that previous recommendations are eventually superseded, but to such an extent that they routinely pull a complete volte-face—does lend itself to satire. 

Worse than provoking laughter, however, such overweening pride in the consensus of the moment can do actual harm. In Jarry's novel, the doctors and public health experts go so far as to pipe undrinkable water into people's homes, in order to force them to consume more alcohol, in line with shifting recommendations. So too, in real life, the "fat-free" dietary craze may have perversely caused, rather than ameliorated, the country's obesity epidemic, by leading people to replace fat with sugar. 

And so the pendulum keeps swinging—hopefully converging toward some center; the natural equilibrium that oscillates around the line of truth. But its wider swings can cause grave damage to people standing by in the meantime. Perhaps, then, we should beware the pious certainties of the advisors. Perhaps, we should answer the vaunted bromides of the health experts and the dietary gurus with some advice of our own—an ancient adage: physician, heal thyself!