The Hero Myth on Your Grocery Shelf

In 1917, the United Fruit Company had a logistics problem dressed up as a cultural one. Its steamers were arriving in Boston and New Orleans loaded with bananas from Honduras, Guatemala, and Costa Rica, and the average American had no idea what to do with them. The fruit was foreign, oddly shaped, and prone to rotting within days of purchase. To move inventory at the scale the company’s plantations were producing, United Fruit needed Americans to eat bananas the way they ate apples: routinely, unthinkingly, as a staple.

So the company invented a word.

In pamphlets distributed to doctors, schools, and women’s magazines, United Fruit began promoting the banana as a “super food,” a phrase that appears, by most accounts, for the first time in print in their promotional literature from that period. ¹ The pamphlets carried medical-sounding endorsements. Pediatricians were encouraged to recommend mashed bananas for infants. Nurses were told the fruit could treat celiac disease. Athletes were promised endurance. Within a few years, banana consumption in the United States had more than doubled, and a marketing concept had quietly entered the language. ²

The word would lie dormant for most of the twentieth century. It returned in the 1990s with the force of a religious revival, attached this time not to a single fruit grown on contested land but to an entire ideology of eating. That ideology, dressed in the language of cellular biology and sold at a markup, still governs the produce aisle today. It is also, when examined closely, largely incorrect.

A Word Without a Meaning

The first thing worth understanding about the term superfood is that it has no scientific or legal definition. Not in the United States, where the Food and Drug Administration regulates health claims on packaging but does not recognize the word. Not in the United Kingdom, where the Advertising Standards Authority treats it as marketing copy. In 2007, the European Union went further and effectively banned its use on food labels, requiring that any health claim be backed by specific, approved scientific evidence. ³ After that ruling, the word vanished from European packaging almost overnight, only to return in softer forms on blogs, in cookbook titles, and in the descriptions of smoothie chains.

The absence of a definition is the entire point. Because the word means nothing in particular, it can mean anything a marketer wants it to. A handful of almonds can be a superfood. So can a teaspoon of bee pollen, a powdered mushroom, a sea vegetable from the coast of Brittany, a berry from the Amazon. The category is infinitely expandable, which is precisely what makes it commercially valuable. There is no committee to satisfy, no trial to pass, no nutrient threshold to clear. There is only the willingness of a copywriter and the appetite of a consumer who has come to believe that some foods are heroes and the rest are background.

This belief did not arise spontaneously. It was built, painstakingly and profitably, on the back of a scientific idea that turned out to be more complicated than its popularizers admitted.

The Chemist and the Free Radical

In 1956, a chemist named Denham Harman, working at the University of Nebraska, published a paper proposing that aging itself was caused by a class of unstable molecules called free radicals. These molecules, byproducts of normal metabolism, carry an unpaired electron and react aggressively with whatever they encounter, including the DNA, proteins, and lipid membranes of human cells. Over decades, Harman argued, the cumulative damage from these reactions was the reason bodies grew slower, skin thinner, organs less reliable. ⁴

Harman’s hypothesis was elegant, and it gave aging a single, addressable cause. If free radicals did the damage, then molecules that neutralized them, the antioxidants found abundantly in fruits and vegetables, ought to slow the process down. The theory was tidy, mechanistic, and seemed to align with epidemiological data showing that people who ate more produce tended to live longer and develop less heart disease.

For several decades, the free radical theory of aging was the dominant framework in gerontology. It produced an enormous body of research and, beginning in the 1980s, an enormous body of products. Vitamin E supplements. Beta-carotene capsules. Selenium tablets. Each promised to do at the cellular level what celery and spinach were presumed to do at the dietary one, only more efficiently and in pill form.

The theory needed a way to rank foods, and in the 1990s it got one. Researchers at the United States Department of Agriculture, working with colleagues at Tufts University, developed the Oxygen Radical Absorbance Capacity scale, known by its acronym ORAC. The test measured, in a laboratory setting, how effectively a given food could neutralize free radicals in a test tube. It produced a single, clean number that could be printed on packaging and compared across products. ⁵

Blueberries did well on the ORAC scale. So did pomegranates, dark chocolate, and a small purple fruit from the Brazilian Amazon called acai. Marketers had what they needed: a number, a story, and a list of winners.

The Decade of the Berry

The two thousands belonged to the berry. Acai pulp arrived frozen from Brazil and was blended into bowls topped with granola. Goji berries from northwestern China appeared dried in trail mix and tea blends. Maqui, a small dark berry harvested by the Mapuche people of Patagonia, was marketed as containing more antioxidants than anything else on Earth, a claim that was recalculated and resold every eighteen months as a new contender emerged.

The economic stakes were significant. By the mid two thousand tens, the global market for foods marketed as superfoods exceeded one hundred and thirty billion dollars annually, with the category growing faster than packaged food as a whole. ⁶ Whole Foods built sections of its produce floor around the concept. Trader Joe’s filled freezers with acai packets. Smoothie chains charged eleven dollars for cups whose primary value, the contents of the cup notwithstanding, was the implicit promise that the drinker was performing health.

Jeffrey Blumberg, a nutrition scientist at Tufts who studied antioxidants for much of his career and helped develop early ORAC methodology, watched the commercialization with growing unease. He and his colleagues had developed the scale as a research tool, a way of comparing chemical properties of food extracts under laboratory conditions. They had not designed it as a guide for grocery shopping. The number a berry produced in a test tube, where antioxidants encountered free radicals directly and in pure solution, was not the number it would produce inside a human digestive tract, where most of those compounds would be broken down, modified by gut bacteria, or simply never absorbed in the first place. ⁷

But the number was on the packaging now, and the number was selling.

The Trials That Broke the Theory

While the marketing was building, the science was beginning to come apart. The free radical theory had always rested on a syllogism: produce contains antioxidants, people who eat produce live longer, therefore antioxidants extend life. The first premise was true. The second was true. The conclusion required that the antioxidants themselves do the work, and that proposition could be tested.

In the late 1990s, researchers in Finland enrolled tens of thousands of male smokers in a trial of beta-carotene, the orange pigment in carrots and a powerful antioxidant in cell culture. The expectation was straightforward. Smokers had elevated rates of lung cancer because their lungs were under constant oxidative assault from cigarette smoke. An antioxidant supplement should reduce that damage and lower their risk. The trial was large, well-designed, and ran for years.

It failed. Worse than that, it reversed. The men taking beta-carotene developed lung cancer at a rate roughly eighteen percent higher than the men taking placebo. The trial was stopped early on ethical grounds. A parallel American study, CARET, produced similar results and was also halted. ⁸

The next decade brought more disappointments. The Selenium and Vitamin E Cancer Prevention Trial, known as SELECT, was launched in 2001 by the National Cancer Institute. Researchers enrolled more than thirty-five thousand men to test whether vitamin E and selenium, taken either alone or together, could prevent prostate cancer. The trial was halted in 2008 when interim analyses showed not only no benefit but a slight increase in prostate cancer among men taking vitamin E alone. ⁹ Follow-up published in 2011 confirmed the result.

Review after review found the same pattern. A 2012 Cochrane meta-analysis of seventy-eight randomized trials, encompassing more than two hundred thousand participants, concluded that antioxidant supplements did not reduce mortality, and that some, particularly beta-carotene and high-dose vitamin E, appeared to slightly increase it. ¹⁰ The free radical theory had not been disproven exactly, oxidative stress is still considered a contributor to aging and disease, but the simple intervention it suggested, more antioxidants in, less damage done, was not how the body actually worked.

In 2012, the USDA quietly removed its ORAC database from the public web. The accompanying notice explained that values from a test tube assay could not be used to predict health effects in humans, and that the database had been so widely misinterpreted by marketers and consumers that maintaining it caused more harm than good. The agency was, in effect, withdrawing the central piece of infrastructure on which the antioxidant superfood economy had been built. ¹¹

The market kept growing anyway.

What the Long-Lived Actually Eat

If the heroic single food does not exist, the question becomes how to account for the genuine and well-documented benefits of diets rich in plants. The answer lies in a slower, less marketable line of research, the kind that takes decades to produce results and cannot be reduced to a number on a label.

In 2004, a National Geographic Fellow named Dan Buettner, working with demographers and epidemiologists, began identifying regions of the world where people lived measurably longer than average and remained healthy into their nineties and beyond. He called these places Blue Zones. The list included Sardinia, the Greek island of Ikaria, the Nicoya Peninsula in Costa Rica, the Japanese island of Okinawa, and a community of Seventh-day Adventists in Loma Linda, California. ¹²

The diets of these populations varied considerably. Okinawans ate sweet potatoes, soy, and a small amount of fish. Sardinian shepherds ate sourdough, fava beans, sheep’s milk cheese, and red wine. Loma Linda Adventists, many of them vegetarians, ate beans, nuts, oats, and avocados. Nicoyans ate beans, corn tortillas, and tropical fruit. Ikarians ate wild greens, lentils, olive oil, and herbal teas. No single food appeared in all five diets. None of them ate acai. None of them ate goji berries. None of them had heard of maqui until tourists started asking about it.

What the diets shared was structural rather than ingredient-based. They were largely plant-based, with meat eaten occasionally rather than centrally. They were composed of whole foods rather than processed ones. They included legumes daily. They were low in added sugar. They were eaten communally and slowly. The longevity in these populations was not produced by a hero food. It was produced by a pattern, sustained over a lifetime, embedded in a way of living.

The most rigorous evidence for such a pattern comes from a Spanish trial called PREDIMED, which randomized nearly seven and a half thousand participants at high cardiovascular risk to either a Mediterranean diet supplemented with olive oil, a Mediterranean diet supplemented with mixed nuts, or a low-fat control diet. Published initially in 2013 and republished after methodological revisions in 2018, the trial found that participants on the Mediterranean diet had roughly thirty percent fewer major cardiovascular events than the control group. ¹³ Subsequent analyses found similar reductions in all-cause mortality and in incidence of diabetes and certain cancers, with the magnitude of benefit clustering around the twenty to twenty-five percent range across outcomes.

The Mediterranean pattern, like the diets of the Blue Zones, has no single hero. It contains olive oil, vegetables, fish, legumes, whole grains, and modest amounts of wine and dairy. The active ingredient, if such a phrase applies at all, is the whole package. Removing any single component would probably not dismantle the benefit. Adding any single component to an otherwise poor diet would probably not produce the benefit.

This is not a finding that lends itself to a label. There is no number to print, no berry to feature, no exotic origin story to tell. The diet is, in the most literal sense, what people in southern Italy and Greece happened to eat in the 1960s when researchers first noticed how few of them were dying of heart attacks.

The Persistence of the Myth

Given the evidence, it is worth asking why the superfood concept survives at all. Part of the answer is commercial. A company that grows commodity blueberries in Michigan needs a way to differentiate its product from blueberries grown in New Jersey, and a generic health halo is cheaper than improving flavor or sustainability. Part of the answer is psychological. Humans appear to prefer narratives with protagonists, and a diet composed of variety and moderation does not satisfy that preference the way a single magic ingredient does.

There is also a deeper structural problem with how nutrition science enters public consciousness. A randomized trial of a dietary pattern takes years to run, costs millions of dollars, and produces a result that is difficult to summarize. A laboratory measurement of antioxidant activity in a berry takes an afternoon, costs almost nothing, and produces a single number. The press releases that travel furthest are the ones with numbers in them, and the numbers that travel furthest are the ones that imply a clean, simple action the reader can take. Buy this. Eat this. Avoid that.

The result is a public information environment in which the most rigorous findings, the ones about patterns and long horizons, are the hardest to communicate, and the least rigorous, the ones about single foods and immediate effects, are the most heavily promoted. The superfood is the natural product of that asymmetry.

There is no reason to stop eating blueberries. They are a fine fruit, modestly priced when in season, and they contribute usefully to a varied diet. The same can be said of kale, of walnuts, of sardines, of lentils, of plain old apples. None of these foods will save anyone’s life on their own. All of them, in combination with others like them, eaten regularly over many years, will probably help.

The word superfood, when it appears on a label, is not really making a claim about the food. It is making a claim about the buyer, that the buyer is the sort of person who eats well, who pays attention, who has done the research. The premium price is the cost of that identity. The product itself is, almost always, an ordinary food that grew somewhere and was harvested by someone, and that would be just as nourishing without the marketing.

The banana of 1917 was not a superfood, and the acai bowl of 2017 was not one either. They were fruits, with the chemistry of fruits, doing what fruits do. The word that linked them across a century has had a long and profitable career. The science has moved on. The shelf has not.

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