Saccharin, Trans Fats… Why Do Healthy-Eating Trends Keep Turning Out to Be Wrong?

Every time nutrition science lights up a new patch of ground, food companies rush out foods that are "absolutely healthy," and consumers pile in right behind them. Everyone believes the same thing: you can't eat too much of something that's "absolutely healthy."

What's healthy to eat? You have more choices than ever before.

Vegetarianism is one trend that can't be ignored. In social settings, more and more people say "I'm a vegetarian" — whether the reason is health, environmental friendliness, or animal welfare, it signals a distinctive kind of identity.

The ketogenic diet, with its emphasis on low carbs and high fat, has been a lifeline for people who don't want to diet or exercise but still want to lose weight just by eating meat. It's said to relieve headaches, reduce liver fat, prevent diabetes, sharpen concentration, and boost intelligence — the list runs on too long to print, but it all comes down to one sentence: it makes you feel better.

"Gluten-free" (GF) is another dietary label chased by celebrities and athletes. After moving from a diet for people with allergies to a synonym for vitality, slimness, and energy, it turned into a healthy lifestyle with an almost legendary aura.

And don't forget the superfoods, led by quinoa and chia seeds. "More than twice the protein of ordinary meat," "rich in vitamins and minerals," "high fiber, low calorie, antioxidant" — all of it boils down to one simple word: super.

Just hearing about it sounds like it could keep you young forever.

And at the same time, the scientific research behind the health claims of the Mediterranean diet — popular for nearly a decade — turned out to have problems.

This June, the New England Journal of Medicine (NEJM), published by the Massachusetts Medical Society, retracted a 2013 study claiming that the Mediterranean diet cut the risk of cardiovascular disease by 30% compared with a low-fat diet. The reason: the methodology was flawed, which made the results entirely wrong. The corrected findings show that the Mediterranean diet is not a direct cause of reduced stroke and heart disease.

The Mediterranean diet's advice to cut back on red meat echoed the century-old, specious idea that "saturated fat is an unforgivable sin." Once it was certified by the New England Journal of Medicine, the most widely read medical journal in the world, the Mediterranean diet was smoothly promoted to the status of dietary myth.

The report was cited by more than 3,000 scientific journals, and it shaped the field of nutrition and health science deeply. Almost every month, a new study on the benefits of the Mediterranean diet is published. The same year the report came out, UNESCO added the Mediterranean diet to the intangible cultural heritage lists of several European countries.

At the end of 2015, the International Foundation of Mediterranean Diet was founded, saying it aimed to improve fast-food culture and preserve Mediterranean diet culture. The Mediterranean diet pyramid drawn up in 1993 by nonprofits and Harvard nutritionists became the center of attention — it even "thoughtfully" listed the food companies that met the standards of the Mediterranean diet, including the pasta maker Barilla, the condiment company McCormick, and the seasoned-butter company Président.

Retracting one study doesn't drop the Mediterranean diet to the level of McDonald's. But neither is it the cure-all healthy food that nutrition science has promoted it as.

And right when the New England Journal of Medicine was pulling the report, the Naples Pizza Festival was still selling an "anti-cancer pizza" developed on Mediterranean-diet principles, in a collaboration between vendors and a cancer research center.

Ever Since Humans Had Enough to Eat, We've Kept Discovering New Healthy Diets — and Then Disproving Them

Any diet that's "better for you" tends to travel the same road: an authoritative scientist or doctor supplies a respectable-sounding rationale; nutritionists then endorse it (sometimes the two happen at once); the government, acting decisively for public health, issues advice along the lines of "eat A, not B"; and then media coverage plus marketing by big companies remakes an entire generation's eating habits.

In the end, even if a study only shows that something is better in one particular respect, with no guarantee that it beats the food it replaces in every other respect, people become sure of one thing: replace the bad with the good, then eat as much of the good as you can — it can't hurt.

In the 1960s, the New England Journal of Medicine published a study by two Harvard nutritionists on sugar and coronary heart disease, concluding that sugar wasn't the problem — only changing fat and cholesterol intake could prevent coronary heart disease.

At the time, clogged arteries were killing large numbers of patients, but whether sugar or fat was the real cause of coronary heart disease was still fiercely contested.

A study published in a prestigious scientific journal not only steered the direction of the whole scientific debate, it also led more nutritionists and government bodies to start telling people to eat more or less of certain foods. Health officials at the time warned that saturated fat was harmful to health in every way and beneficial in none.

Lengthy papers were boiled down to catchy health slogans, which were then printed on food packaging. Advertising copy first convinced Americans that sugar was harmless and low fat mattered more — and then, following American food companies, convinced the rest of the world too.

Today, a whole roster of food industry giants are in the "sugar" business — Kraft Heinz, known for ketchup and crackers; Coca-Cola, the largest maker of sugary drinks; Nestlé, with over a thousand snack brands; and Mars, a food company with more than $30 billion in annual revenue.

But later, more and more studies found that too much sugar hurts health even more than fat does.

Over the past decade, the American Heart Association, the World Health Organization, and other health bodies have all issued statements saying that a large rise in sugar intake may also raise the incidence of cardiovascular disease.

It later emerged that the report published back then in the New England Journal of Medicine had been backed by sponsorship worth about $50,000 in today's money, meant to protect sugar's reputation with the public. Both authors have since died, and neither ever disclosed where the money came from.

A 2015 New York Times article also pointed out that Coca-Cola had given researchers millions of dollars in an effort to weaken the link between sugary drinks and obesity.

Another healthy-eating trend that collapsed around the same time as high-sugar-low-fat was trans fat.

Before the 1990s, everyone from nutritionists to the American Heart Association to the FDA believed that hydrogenated vegetable oil, made mostly of unsaturated fatty acids, and the trans fat it contained, were healthier, more nutritious substitutes for animal fat.

It wasn't until the late 20th century that a growing body of research proved that partially hydrogenated vegetable oil contains trans fat that triggers fatal heart conditions — even a hundred times worse than animal fat. Food and drug regulators around the world, and the food industry itself, then scrambled to get hydrogenated oil out of use.

This pattern has repeated from the birth of nutrition science up to the present.

The British physician and chemist William Prout concluded that food is made up of three main components: protein, fat, and carbohydrates. Then Justus von Liebig, the German chemist who proposed nitrogen-phosphorus-potassium fertilizer and founded the fertilizer industry, added a few minerals to these three substances and declared that he had solved the mystery of nutrition. On that basis he went on to make beef extract and infant formula.

But sailors who ate by Liebig's principles still fell ill often, and infants fed his formula grew more slowly than those fed breast milk. The reason, it was later concluded, was a lack of vitamins.

Cases like this come around again and again in history.

Milk was once blamed as a source of typhoid infection, and it was pasteurization, funded by dairy giants, that finally dispelled people's fears. Saccharin, the first low-calorie substitute for sucrose, was once used widely across the food industry (including in Diet Coke); in less than a decade, scientists found it was a suspected carcinogen and it was pulled from use across the board (only for people to find, more than a decade later, that there was no solid evidence it caused cancer).

The Research Is Unreliable Because We Still Know Too Little About What Affects Health, and Comprehensive Studies Are Impossible

What nutrition science has to answer is how diet affects human health over an entire lifetime. But researchers can't recruit thousands of people, split them into groups, and watch what happens if each group eats only one diet for life.

Even in the most extreme human experiments in history, scientists could never get it exactly right.

In 1902 there appeared America's so-called Poison Squad, who supposedly sacrificed their own health for the public good.

At the time, chemical preservatives and adulterated substances had the public in a panic, and scientists began taking sponsorship from business groups and government agencies to launch one Poison Squad after another, made up of low-paid young government employees.

Some were required to eat three meals a day laced with "preservatives" supplied by the researchers, for anywhere from three to five years; others tested whether soft drinks contained opium, cocaine, and caffeine; one squad even ate food containing the preservative sodium benzoate for more than five years. Some researchers even wanted to test baby food, but a squad of test-subject infants never came together.

A song about it is said to have made the rounds in circuses at the time:

"They eat a batch of poison with every meal. Breakfast is liver with cyanide added, cut into the shape of a coffin."

In the end, of course, no member of any Poison Squad was poisoned, and chemical additives including sodium benzoate duly joined the FDA's "generally recognized as safe" list.

Across this whole string of poison-tasting examples, even the squads that got government and corporate funding to stretch their experiments past five years were still negligible next to the decades of a human lifetime — never mind the experiments back then that confidently drew conclusions after only a few hundred days.

Modern society could never permit this kind of "testing poison on your own body" either — it violates basic humanity and scientific ethics.

In the end, most concepts in nutrition science come from studies that test only one nutrient at a time. That is also the most basic logic of scientific research: strip away every other factor and look at a single variable to establish cause and effect — otherwise there's no way to show what difference that variable's presence or absence makes.

But this seemingly rigorous way of experimenting underrates the complexity of the interactions among a food's components, between food and the human body, and among the differences between individual bodies.

Peanut butter spread on bread, for instance, affects how fast the body responds with insulin; eating steak with coffee means the body can't fully absorb iron; adding a little olive oil to tomatoes helps the body absorb lycopene.

At the same time, people aren't machines — you can't treat food as pure fuel.

Some people love fried chicken and stay thin anyway; some people metabolize sugar better than others; some people can't digest lactose that others digest with ease. These differences may come from the pace of evolution, genetic material, environmental influences during growth, or other causes we haven't even thought of.

Food is also more than a bundle of pure nutrients, and exactly how it affects health is still being discovered. Take vegetables and fruit, long seen as protecting against cancer. Researchers once assumed this had to be thanks to the antioxidants in produce, such as beta-carotene, lycopene, and vitamin E. But new research has found that once these components are separated from whole, natural food, they stop working — and beta-carotene may even raise the risk of lung cancer in people already at high risk for it.

Nutrition science has carried these inherent flaws of scientific method with it ever since it began.

The great chemist Liebig declared that he had solved the mystery of nutrition: food's main components were nothing more than protein, fat, carbohydrates, and a few minerals. He founded a company to sell beef extract and infant formula, never expecting that his formula was still missing something — vitamins, which he could not possibly have anticipated, since they weren't discovered until 40 years after his death.

Once vitamins were discovered, they instantly became a cure-all for every health problem. The question "What should I eat?" turned into "Which nutrients do I need to take in?"

With science behind them, whatever nutrients were lost in food processing could simply be replaced with vitamins — which was cheaper. Since the technology to measure vitamin content didn't yet exist, any food company could claim its products had vitamins added, including makers of chocolate, chewing gum, and white bread.

Vitamin supplements have kept growing ever since, into a business worth tens of billions of dollars today.

Despite numerous studies, it still hasn't been proven that extra vitamin supplementation helps prevent chronic disease or extend life. But taking vitamin pills has become an article of faith: after I take them, I'll feel better.

Nutrition Evangelism That Simplifies the Message Magnifies the Limits of Scientific Research

Asking everyone to read a paper dozens of pages long is asking too much. And even the most rigorous study, once squeezed into a one-line health slogan, often ends up meaning something else.

Let's go back once more to where the vitamin craze began.

In the early 20th century, the Polish biochemist Casimir Funk discovered vitamins and concluded they were substances essential to life. A diet lacking this water-soluble cofactor could indeed cause certain diseases, such as the beriberi common among people in Southeast Asia. But vitamin deficiency was rare in American cities at the time — everyday food already contained vitamins. Even so, fear that a vitamin shortage could harm health still spread.

The leading chemist Elmer McCollum showed reporters the results of an experiment on 3,000 rats. The New York Times reported in 1930 that the rats given no vitamins were, one and all, gaunt, agitated, and wasting away to death. The rats fed vitamins, by contrast, were relatively sturdy, with glossy coats and clear eyes.

Vitamins were soon boiled down to a synonym for "longevity." For food manufacturers, this was a gift from heaven.

McCollum was invited to endorse white bread, whose sales were sliding, and he argued that eating white bread with milk and vegetables was healthier than eating whole wheat bread. Bread manufacturers later launched fortified bread with added vitamin B and iron, which got strong government backing.

Vitamin C also drew intense attention thanks to scurvy, a disease that barely existed in the United States. Sunkist cited scientific data to recommend drinking two full glasses a day of vitamin-C-fortified, non-natural orange juice — enough, it claimed, that you'd never need to eat fruit for the rest of your life.

People must have been making frequent trips to the bathroom back then, since the dietary advice of the day also called for drinking nearly a liter of milk a day.

Starting around 1998, concentrated juice — once virtually a synonym for vitamin C — gradually fell out of favor. People stopped paying for the sugar and fat that had become plainly visible, and also began worrying that concentrated juice lacked the fiber important for gut motility — the very thing nobody had yet found any use for back when vitamins first became popular.

From 2012 to 2016, total U.S. sales of orange juice across all categories fell 13%, with frozen concentrated orange juice down 39%.

In 2014, the principal of an American elementary school issued a rule: cut juice from lunch, and drink more water when you're thirsty. Susan Jebb of the Medical Research Council unit at Cambridge told the Sunday Times: "Sweet juice isn't the same as whole fruit — its sugar content is nearly as high as soda, and it has little nutritional value."

Fiber became nutrition science's new favorite, and at first the response was simply to go back to eating vegetables and fruit. But the food processing industry quickly followed the same old formula — whatever is deemed healthy, add it in. Fiber drink mixes, fiber crackers, fiber-infused light waters... started appearing on shelves.

Sprite Fiber+, which Coca-Cola China launched this March — its "fiber" means "resistant dextrin," a water-soluble dietary fiber that creates a feeling of fullness — even brought on Dilraba Dilmurat as spokesperson, shooting a series of ads called "Dilraba's Secret to Staying Light," tying "Sprite" to health and weight loss, and hammering the message into audiences through online video and offline convenience stores alike: "Sprite Fiber+ is rich in dietary fiber."

But resistant dextrin, sold on the gimmick of "sucking up fat," has in fact long been used widely as a thickener in foods like ice cream, milk powder, and yogurt — and no one can become "light" by taking in a single nutrient from a soft drink.

Research findings in nutrition science that are still open to question, along with unsolved limits in that research, get reduced — under food companies' billions of dollars a year in marketing — to a single line: "food that's better for you." But how is that any different from the old promise that vitamins would solve everything?

It's Food Companies, in the End, That Turn Concepts Into Food and Get It Into Your Stomach

Every time a food or a way of eating becomes a mass trend, food companies grow along with it.

General Mills launched a gluten-free version of its Rice Chex cereal brand in 2008, and the move instantly won General Mills a following. In the first quarter of fiscal 2012 alone, Rice Chex sales rose 29%.

Besides producing more vegetarian recipes and restaurants, the vegetarian trend also pushed the share of chocolate and candy labeled "vegetarian" or "vegan" from 1% in 2009 to 9% in 2013. By the end of 2016, the market for vegetarian products had grown to $4.126 billion.

In 2013, Coca-Cola launched Coca-Cola Life, sweetened with stevia, and switched the bottle to green to evoke "natural." The product did fairly well. Data from IRI shows that a year after launch, Coca-Cola Life's sales reached £28.9 million (about 248 million yuan) — more than four times the typical first-year sales of a new product.

On the more niche end, bulletproof coffee — which rode to popularity on the back of the ketogenic diet — has its top-selling version on Taobao made by Yeshou Shenghuo; the brand's latest, fourth-generation product sold roughly 40,000 bottles within three days of launch.

Every time nutrition science lights up a new patch of ground, food companies swarm in with "absolutely healthy" food to tempt consumers.

Food companies do this for a reason: this is an industry dominated by a handful of giants.

According to data released by the consultancy A.T. Kearney, U.S. food and beverage sales reached $495 billion in 2016, and 25 large food and beverage companies — including Nestlé, McDonald's, Kraft Heinz, General Mills, Coca-Cola, and Hershey — held 63% of the market.

Nestlé alone owns more than 2,000 brands, spanning categories that include coffee and tea, chocolate and candy, bottled water, dairy and ice cream, and nutrition and health products.

Coca-Cola sells 160 beverage brands across 200 countries, equal to a 48% share of the global beverage market, and has likewise expanded from soda, sports drinks, and dairy all the way to juice, tea, and coffee.

The chocolate maker Hershey sells more than 80 chocolate and candy brands worldwide; last year it posted revenue of $7.515 billion and profit of $780 million, up 8.7% year over year.

For these brands, whose average age tops a hundred years, every product launch reaches thousands of points of sale worldwide. And health is a reason everyone is willing to pay for.

Scale isn't a bad thing — humanity largely escaped hunger thanks to the industrialization of food: large-scale livestock farms and meat-processing plants that drove down the cost of high-protein products. Cheap fast food and supermarkets sprang up like mushrooms after rain. Along the chain from farm to table, processing technologies — refrigeration and freezing for preservation, chemical preservatives, aseptic packaging — appeared one after another, helping these big companies feed more than half the planet.

But scale also makes them an industry that watches costs closely: anything nutrition science hasn't yet found value in gets stripped out fast. That was once true of saturated fat, and of plant fiber.

And whatever the nutrition trends call effective gets added right back in, and set equal to health.

History keeps repeating itself. Lesson after lesson has come and gone, yet the food industry remains as robust as ever — as long as it keeps combining nutrients with guilt-inducing processed food, and rolling out new "foods" "guaranteed to be good for your health," consumers will keep enjoying, without restraint, the flavor and nutrition that industrialization delivers, believing that you can't eat too much of something healthy.

Consumers Push Back, Then Embrace the Next New Health Theory

Years of research into food and investigative reporting, along with the 2009 documentary Food, Inc., exposed the food industry's effect on health.

The panic caused by obesity (and the fear of it) seeped into every corner of urban life. Between 1998 and 2009, the number of times the New York Times mentioned the word "obese" tripled; mentions of "diabetes" are now ten times what they were when the term first appeared in 1970. The phrase "obesity epidemic" first appeared in the New York Times in 2002, and has recurred without a break ever since.

The dietary trend reversed. People began to crave more information behind the ingredient list, and to want to know the direct effect on the body of all those complicated chemical names.

Rising health consciousness among middle-class consumers drove a new wave of interest in organic, local, small-farm food.

Over the past decade, almost every chef in America has been talking about organic farming — even the agricultural biotech company Monsanto and McDonald's have joined in. Dan Barber, chef at Blue Hill, a Michelin one-star restaurant in New York and one of the best practitioners of this approach, calls it pushback against a global food economic system that's eroding culture and cuisine: "It's directly connected to seasonality, place, and the farmer, and at the same time you get to taste better food."

This has made life increasingly hard for big companies.

Kraft is considering buying the underperforming Campbell Soup Company. The latter, seen as selling high-sodium, not-fresh canned soup, has found the business increasingly difficult.

McDonald's performance has also disappointed: its revenue has fallen every year since peaking at $28.11 billion in 2013, and the company has been searching constantly for ways to make itself more fashionable and healthier.

Since 2012, as consumers have cut back on junk food and sugary food, Nestlé's confectionery business has trended downward overall as well; this year it sold three of its candy brands to the Italian chocolate maker Ferrero.

Independent founders in niche categories, spawned by small-scale dietary trends, also pose a threat to the big companies.

Functional drinks built around "superherbs" have started eating into the sports-drink market long dominated by PepsiCo, while thick smoothies made of fruit, vegetables, and protein have been chipping away, step by step, at the market share of 100% juice.

Big companies respond either by changing themselves to fit the new trends, or by buying independent brands that need capital to expand.

McDonald's has been moving step by step toward a "better McDonald's": it took the preservatives out of Chicken McNuggets, hid part of the menu for Happy Meals, and switched some frozen beef to fresh beef — spending more than $60 million to do it.

In 2014, among the top five soda brands by sales on Amazon US, a new name appeared for the first time alongside old standbys Coca-Cola, Pepsi, and Dr Pepper: Zevia. In the first half of that year, U.S. carbonated soft drink sales fell 7.5% year over year, while Zevia's sales rose 67% year over year. Its formula used the same stevia that the cola giants would later embrace.

Last year Nestlé spent $500 million to take a controlling stake in Blue Bottle, the specialty coffee brand that became a Silicon Valley sensation (valued at $700 million). Blue Bottle has 50 stores in the U.S. and Japan and is one of the standard-bearers of the third-wave coffee movement, which emphasizes fresh beans, origin, and baristas.

PepsiCo recently acquired Bare Foods, a maker of dried fruit and vegetable snacks whose selling point is simple, non-GMO ingredients that are baked rather than fried. In an earlier interview with the media, Bare Foods CEO Santosh Padki remained critical of the traditional packaged-food industry, arguing that the big companies' food has quality problems and fails to connect with consumers.

Independent brands, short of capital and unable to go public easily, keep getting bought up by big companies one by one. But after an acquisition, does the independent brand end up reshaping the big company's sourcing and processing — or does the big company reshape the independent brand's product to fit mass production?

Once a big company's food is made, it has to be shipped out to many more sales channels, which means different requirements for shelf life, cost, and a taste suited to the mass market.

Lechun yogurt, which this year received a strategic investment from Coca-Cola after several years of mass production, started out with the goal of restoring yogurt to its original form, its selling point being zero additives and zero-fat or low-fat. Its founder, Zhang Nannan, left the company after a little more than a year, and the formula changed as well. Lechun responded by saying that the formula Zhang Nannan had developed was an early, still-immature version of ordinary yogurt, different from the Greek yogurt with "triple-triple-triple" nutrition that Lechun makes today.

Once the product moved into scaled-up production, Lechun added more ingredients beyond yogurt itself, and it became sweeter and higher in calories (6 grams of fat per box). But the premium that slogans like health, natural, and weight loss command hasn't gone away — a 135-gram cup of Lechun yogurt now costs 16.9 yuan, considerably more than the average under-10-yuan yogurt from other major brands.

The fight between industrialized food and natural, organic food will keep going.

Since the 1980s, American nutritionists have raised the "French paradox" — the French diet is full of high-fat foods, yet the French have a far lower rate of cardiovascular disease than Americans, who eat according to the most "scientific" principles. The End of Overeating offers an unproven explanation: the French take longer over meals and eat smaller portions, which may be the key to their lower rate of cardiovascular disease.

But health without solid scientific backing isn't an easy concept to sell. New, supposedly healthier nutrition theories keep being born anyway, alongside the health anxiety that never lets up.

Healthy-eating trends keep shifting, even when they contradict each other. Someone who swore by gluten-free eating yesterday becomes a believer in the high-fat, low-carb ketogenic diet today.

The health crisis caused by processing replacing nature hasn't fully passed, and already "food terminator" Soylent — a fully synthetic powdered meal-replacement nutrient paste — has become the new fad.

Some things never really change.

Cover image sources: Wikimedia Commons, Eric May on Flickr, Fancycrave on Unsplash, Brooke Lark on Unsplash