The coconut water health fad hit New York City in 2004. Mark Rampolla, the founder of Zico, had just returned from a trip to Central America, where he’d seen locals sipping the stuff. His competitors at Vita Coco, now the top brand, had just returned from Brazil and were also trying to market coconut water.

Rampolla would park his van outside yoga studios and offer samples. Sweaty students emerging from trendy hot yoga classes embraced his claims that the drink was natural and replenishing. The lithe, spandex-clad students would head off in all directions with Zico’s logo in

It was a stroke of marketing genius. Even now, when Zico introduces its products to a new market, the company first builds brand loyalty at local yoga studios.

By 2013, coconut water was the health food to have, buoyed by claims that it’s exactly as saline as blood and therefore restores the body to its pristine state after a workout — or even just a hard day. Even Coca-Cola had gotten in on the action: The beverage giant acquired a controlling share of Zico in 2012. Dr. Oz had touted coconut water as “one of the most hydrating liquids out there.”

But what does all that really mean?

coconut water

Nutritionists describe coconut water as a natural sports drink. As sports drinks go, it’s not a bad one. Unlike Gatorade, it doesn’t contain artificial colors. Enthusiasts can avoid added sugars and sugary fruit purees if they steer clear of the many fruit-flavored varieties and stick to plain coconut water.

But only a tiny fraction of fitness buffs push themselves hard enough to need a sports drink, nutritionists say. A 2012 study funded by Vita Coco found that the company’s $0.12-per-ounce product was no better than water at hydrating athletes after hour-long workouts. Those who don’t need to recoup calories and electrolytes add 43 milligrams of salt and 10 grams of sugar to an American diet that’s generally already too rich in both.

“Drink it if you like it, but don’t assume it’s a powerful, much-needed food in your diet,” advised Joan Blake, MS, RD, LDN, a clinical associate professor of nutrition at Boston University.

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Building Foods up with the ‘Health Halo’

In recent years, the number of foods touted as dietary magic bullets has grown rapidly. The 1980s saw grapefruit and cottage cheese diets. The past 10 years have seen coconut water, Bulletproof coffee, juicing and cleanses, raw foods, acai and goji berries, Greek yogurt, kale, chia seeds, and fermented foods and teas — not to mention fad diets such as the paleo diet.

These nutritional claims often appeal to our primal ways of thinking. Many are said to cleanse or restore our bodies to like-new condition. Others bring traditional wisdom into the modern world: Acai berries purportedly emerged from the Amazon rainforest, and goji berries came down from the high Himalayas. The paleo diet returns us to the simplicity of more primitive times.

Brian Wansink, director of the Food and Brand Lab at Cornell University and the author of “Slim By Design: Mindless Eating Solutions for Everyday Life,” says these claims create a “health halo” that surrounds certain foods. Once a food acquires a health halo, consumers often ignore nutrition labels and price tags alike.

“People tend to underestimate the amount of calories in that food and overestimate the health benefits,” he said.

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Consumers are eager to find foods on which to hang these health halos. They want to eat healthier, but they don’t want to commit to the hard work that a diverse, healthy diet can require.

“People are always looking for something new. They’re ready to hear about something that could be ‘it,’ that this is the magic bullet,” said Blake.

The trouble is, there’s no such thing as magic. What consumers are usually buying is marketing.

“As to why these and other foods are considered health foods, the answers vary — sometimes it’s preliminary research that always ends with ‘and more research is needed.’ More often it’s good PR on behalf of companies, importers, or ideologists promoting their products or views,” said food historian Andrew F. Smith.

Many fad health foods are potentially healthy, but not miraculously so and only when they’re part of a nutritionally sound diet. Chia seeds are just as healthy as any other seed. Kale and wheatgrass are nutritious leafy greens, but they’re no better than spinach. There’s nothing wrong with acai or goji berries, but it would be hard to make the case that those berries are better than, say, blueberries.

“All plants have antioxidants,” said Blake. “Do I need to have an expensive berry? Is it going to have any superior nutritional benefit over another plant food?”

Nutritionists take issue with the way fad foods key in on a single potent ingredient, rather than accept the healthful blend found in most vegetables and fruits. The most extreme example is juice diets, which literally filter out the beneficial fiber as if doing so would make the remaining vitamins more powerful.

Dr. Ranit Mishori, a family medical doctor and professor at Georgetown University School of Medicine, has reviewed the scientific literature on juice cleanse diets. Her conclusion is that any promise that a food will “cleanse” is “complete nonsense.”

“The human body was set up to ‘detox’ itself 24 hours a day and for free. It does so through the kidneys, the liver, the skin, the immune system, and the lungs. Despite marketing claims, ‘toxins’ do not get trapped in those organs or need external help from some supplements, ‘superfoods,’ or certain types of vegetables or fruit,” she said.

When foods gain a health halo, people tend to simply add them to their diet like they would a supplement, instead of substituting them for less healthy foods.

“People aren’t eating acai berries instead of apples,” Wansink said. “It’s just calories on top of calories.”

The health halo also leads to regular consumption of foods whose health benefits are limited to certain circumstances. A gluten-free diet is healthy for people who have an autoimmune reaction to the protein gluten, found in wheat, barley, and rye. But the hype surrounding gluten-free foods can lead consumers to think that gluten is bad, period. To wit, a gluten-free café in Berkeley, California, bans customers from bringing even packaged gluten products onto the premises.

Following fads like a gluten-free diet when they don’t need it can lead people into eating habits that are less healthy, not more so.

“I’m happy that there are more gluten-free foods, but when you take them and say ‘I’m doing this because I want to lose weight,’ there’s no science to support that. And if you look at gluten-free foods, because they take out gluten, they can have more fat and calories,” Blake said.

Can Coffee Really Make You ‘Bulletproof’?

Few health fads are as commercially driven as Bulletproof coffee, a mix of “low-mold” coffee, butter from grass-fed cows, and a coconut oil extract made from medium-chain triglycerides that supposedly improves brain function.

Bulletproof coffee’s proponents say one cup in the morning instead of breakfast keeps them satisfied, energized, and alert well into the afternoon, while training the body to burn fat for energy, leading to weight loss. Grass-fed butter, according to some, contains healthier fats than cream or cheese.

But there’s no science to support any of these claims. Many people aren’t aware that the claims originate with the company that makes Bulletproof coffee.

Online ads claim that Bulletproof coffee can boost IQ and help you lose weight.

The term “Bulletproof” is trademarked by Dave Asprey, a self-proclaimed “biohacker” who developed the recipe based, he says, on a cup of yak butter tea he had on a cold day in the Tibetan Himalayas. Asprey sells low-mold coffee and the coconut oil extract, which he calls “Brain Octane,” directly. He also sells an herbal sleep supplement and a diet book.

Asprey’s health claims are met with utter contempt from dieticians.

“What you don’t need is to be having a stick of butter!” said Blake. “It shouldn’t displace a breakfast that would be of food, like grains and fruit.”

Liz Applegate, Ph.D., a nutritionist at the University of California, Davis, also scorned the coffee concoction.

“Bulletproof coffee is the best example of something that’s gone viral that’s just ridiculous,” she said.

Here’s what the evidence says. The fats in Bulletproof coffee, like all fats, extend the feeling of fullness, according to nutritionists. But butter in your morning coffee is no more likely to result in weight loss than butter anywhere else, they said.

There’s no reliable evidence that the caseins in cream and cheese are any different nutritionally, gram for gram of fat, than those in milk or butter. Medium-chain triglycerides have no health benefits other than being more easily digested by people who have trouble digesting fats.

“They just make a feasible-sounding yet still confusing claim,” said Katie Ferraro, a registered dietician and an assistant professor of nursing at the University of California, San Francisco. “If I were to reinvent Bulletproof coffee, at least I’d put olive oil in it because those are healthy fats.”

So what about that magical productivity Bulletproof coffee drinkers claim they experience? It’s just a caffeine buzz, nutritionists said.

Blame the Internet for New Food Fads

If there’s no nutritional evidence to fuel them, how do trends like coconut water and Bulletproof coffee take off? We asked Vani Hari, the woman behind the popular website and the forthcoming book “The Food Babe Way.”

“Social media,” she said.

The Internet allows niche groups to connect and share information, and it allows information to spread quickly, sometimes obscuring its source.

There’s a willing audience for new health food discoveries, as the number of health and lifestyle blogs reveals. These sites have to produce new content constantly in order to stay relevant. When one site mentions a hot new food, others often follow suit.

“You’ve got to come up with another miracle week after week because people’s attention spans are short,” said Ferraro. “They’re all variations on a theme. Last year it was Greek yogurt; this year it’s Icelandic yogurt.”

That explains why kale, rather than its equally nutritious cousin, spinach, became a craze: Consumers already knew about spinach.

Celebrities also get in on the game. Dr. Oz has endorsed nearly all of the fad foods mentioned here, and then some. Some of his “miracle” weight loss claims landed him in a congressional hearing last year.

Actress Gwyneth Paltrow’s lifestyle site Goop has also helped push raw and gluten-free diets and, more recently, bone broth. (Traditional meat broths are also made with bone, but “bone broth” is the buzzword du jour.)

Soon after Goop hyped bone broth, Marco Canora, a celebrity chef and serial restaurateur, launched Brodo. The café, located in trendy lower Manhattan, serves bone broth in coffee cups. Canora calls the broth “the world’s first comfort food.”

Journalist Christopher McDougall isn’t a celebrity, but his 2009 bestselling book “Born to Run”was popular enough to launch a couple of health fads. In the book, McDougall describes the fast, joyful, injury-free running habits of a remote indigenous tribe in Mexico. The runners, he wrote, noshed on chia seeds. American health enthusiasts were eager to follow suit, and the seeds began to appear in juicing diets, kombucha fermented teas, and energy bars.

What the natives in the book wore on their feet spurred a second fad: barefoot-style running shoes. Vibram, formerly known for making outsoles for hiking boots, shot to commercial stardom with its FiveFingers shoes.

But the company settled a class action lawsuit in 2012 after the commission pointed out an inconvenient truth: There’s no scientific evidence to support the claim, repeated at gyms and on athletic fields across the country, that barefoot-style shoes result in fewer running injuries.

Health food claims are rarely debunked. The more obviously bogus the claims are, the harder it is for nutritional scientists to get funding to investigate them, Applegate said. It’s not a good use of funding dollars. Researchers could use social media to combat false information, but they’re paid to research and teach, not blog and tweet.

“There are people out there who don’t have the background, and they often outnumber people like me,” said Applegate. “I just don’t feel that a lot of credible people in the world of nutrition can be out there combatting this kind of information.”

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The Food Industry Cashes In

The food industry capitalizes on consumers’ desire for dietary magic to move products off the shelves.

“There’s a caveat with almost everything that becomes a trend. As soon as the thing becomes a trend, the food industry finds a way to capitalize on that, and when they capitalize on a trend that has to do with health, they usually adulterate it,” Hari, the Food Babe, said.

Hari is part of the health-food echo chamber. But she advocates for the least processed forms of trendy foods, including juice, coconut water, and yogurt. She researches which beneficial ingredients they have, and she’s hawkish on processed foods and the dubious, sometimes undisclosed, ingredients they contain.

Take yogurt. Naturally low in sugar and a solid source of calcium, protein, and beneficial bacteria, yogurt has real health-food cred.

Enter Chobani, founded by a Turkish-American man in upstate New York in 2007. Seeing Chobani’s success, Fage, a Greek company, started marketing its yogurt in the United States the following year. Before long, Greek-style yogurts had taken over the dairy case, with food multinationals like Dannon and others entering the fray.

But many of the big brands didn’t want to take the time to strain their yogurt. Instead, they added milk protein concentrate or carrageenan to unstrained yogurt, according to an exhaustive analysis done by the Cornucopia Institute, an advocacy group that supports small, organic farming.

Carrageenan’s safety as a food additive has been widely debated, and the Food and Drug Administration forbids the use of milk protein concentrate in yogurt. Many yogurts, whether Greek or not, also add something else, the Cornucopia Institute analysis shows — sugar, and lots of it.

At the same time, many major brands, including Chobani, are short on the very thing that gives yogurt its edge: the good-for-you bacteria, or probiotics, that turn milk into yogurt. Makers are not required to provide a count of how many active bacteria a serving of yogurt contains. However, some companies voluntarily include this information on the packaging.

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Unlike many nutritionists, Hari believes there’s a longer list of health benefits that don’t show up on food labels, such as the active enzymes in coconut water. She also points out that food companies can legally conceal many industrial processes. For example, the ingredient called high-fructose corn syrup is sometimes labeled simply “fructose.”

But she says the nutrition label is still the best way to tell how healthy a food really is.

“No matter what health trend you choose, you have to look at the ingredient list,” she said.

One Not-So-Simple Trick to Live Longer

Nutritionists insist that the most legitimate healthy diet is the Mediterranean diet, made up of whole grains, fruits and vegetables, and lean meats and fish, with caps on unhealthy fats rather than total fats. There’s a long list of studies supporting the benefits of such a diet for heart and metabolic health and longevity.

The diet’s benefits don’t come from any single food, though some researchers have tried to prove it does. The cultures that pioneered the Mediterranean diet managed to live longer, healthier lives without eating a single so-called superfood.

“If you lived in the Mediterranean, they never had the ‘superfood’ berry,” Blake said.

Of course, the Mediterranean diet also didn’t include Doritos or Coca-Cola, so if food fads drive people to eat chia seeds or drink coconut water instead of fast food and processed foods, nutritionists will call it a win.

“I don’t want people to feel bad for following these things, I just want people to be realistic,” Applegate said.

The key is for consumers to do their own research, starting with nutrition labels. Smart choices about one’s overall diet will have to replace magical thinking about particular foods.

“We’re going to get to the point where it’s going to be the total diet,” said Blake. “We’re going to go back to what your grandmother did — we’re going to go back to food.”