A Few Rational Words about Sugar

Recently I spent the better part of a morning writing on my laptop at a Starbucks in my neighborhood. After an hour or so I took a break to see what was happening on Twitter. The first thing that caught my eye was a tweet from Mark Hyman, a physician and author of several diet books, including The Blood Sugar Solution. He’d just taken a photo of a display case at an airport Cinnabon. Strung across its protective glass, above a mouthwatering selection of pastries, was a sign that read, “Eat me. I’m sweet!” Next to the photograph was this comment from Dr. Hyman: “Drug pushers everywhere. Why don’t they just sell crack at airports instead of Cinnabons.”

I understood the reference. Sugar-as-addictive drug has become a trendy meme lately. Its peddlers believe that sugar has an irresistible power to make people eat more and more sugar and that succumbing to this power destroys health because sugar is toxic—toxic!—in any amount. If you’ve only recently returned from Jupiter and this latest dietary hullabaloo is news to you, just Google the phrases “sugar addictive” and “sugar toxic” and you’ll see what I’m talking about.

The idea that sugar is addictive is based largely on a handful of animal studies from the early 2000’s demonstrating that sugar consumption activates parts of the brain that are also excited by pleasure-inducing opioid drugs. It’s based as well on a few studies of the same vintage showing that rats fed large amounts of sugar for a long period of time tend to develop a dependence-like preference for sugar. Parallel research proved that fat has the same effects, but the anti-sugar crowd doesn’t have much to say about these findings.

As chance would have it, not half an hour before I saw the tweet that I just described I had eaten a Starbucks cinnamon roll, which is very much like the Cinnabon version of the same and contains a whopping 32 grams of sugar (seven grams more than the World Health Organization’s new recommended daily limit for refined sugars). I like Starbucks cinnamon rolls and I eat them perhaps five or six times a year. But I never crave them and I can’t say that I have felt compelled to consume them with ever-increasing frequency since I first tasted one.

I enjoy eating all kinds of confections, not just cinnamon rolls. Bread pudding and cheesecake are my particular favorites. But I don’t eat these or any other desserts often, either—maybe twice a month when dining at restaurants with my wife. I am careful with my diet and I know that eating a lot of sugar is unhealthy, so I don’t. Most of the sugar in my diet is not refined at all but comes from whole fruits. My pantry and refrigerator are almost always devoid of solid and liquid sweets except for a bar or two of premium dark chocolate, which I eat once or twice a day in tiny amounts. I find it not the least bit difficult to keep my sugar consumption at such a low level despite the regularity of my exposure to it.

In short, the claim that sugar is addictive does not square with my experience. Nor does sugar have the appearance of addictiveness with respect to most of the people I know. The majority of my friends and family members are like me—they love a good peach cobbler yet they strictly limit their sugar consumption and they do so without difficulty. And when I think of the fittest and healthiest people I know, I can’t name one who avoids refined sugars altogether. So the claim that sugar is toxic even in small amounts does not square with my real-world experience either.

If sugar is so addictive, where are all the sugar addicts? When folks like Mark Hyman are asked this question, they usually point to the fact that sugar consumption has increased by more than 23 percent in the U.S. since 1970, and they never fail to also mention that the rates of obesity and diabetes have skyrocketed in the same time span. But these are population numbers; addiction is an individual relationship with a particular behavior. It is one thing to say that a society in general is eating too much of something, quite another to say that large numbers of people within that society are addicted to what they’re eating.

I fear that most of the folks who call sugar addictive have no idea what addiction is. A person may become addicted to virtually any behavior that offers pleasure or relief. The vast majority of people who are exposed to a behavior that has the potential to become addictive do not get hooked. Only those who have a psychological susceptibility end up dependent. In other words, the primary source of addiction is the addict, not the substance or behavior upon which he is dependent.

Sugar alarmists are fond of equating the addictive nature of sugar with that of alcohol. Let’s have a look a this. Nearly 70 percent of American adults drink alcohol at least a few times per year, yet only 6 percent drink enough to qualify as alcohol dependent. Meanwhile, 33 percent of alcoholics suffer from depression. Alcohol offers an escape (imperfect and ephemeral) from psychic pain. That’s what makes it potentially addictive. But booze becomes an addition only for those who have an extraordinary need for such an escape.

These dynamics are even starker as they relate to hard drugs such as heroin. Gabor Maté, a psychiatrist who oversees harm-reduction clinics for drug addicts in Vancouver, B.C., has said that every single one of the female heroin addicts he treats is a current or past victim of physical or sexual abuse. One of the arguments against legalizing hard drugs is that doing so would lead to an explosion of abuse and addiction. In fact, legalization would barely move the needle unless it was somehow accompanied by a drastic increase in the rates of physical and sexual abuse. It is not illegality but the absence of inner torment and desperation that keeps most people from using heroin. I mean, would you start buying heroin if it was made legal?

It is true that some substances have more addictive potential than others. Only a select few substances have the power to relieve (again, temporarily) great inner torment. Those that do are the ones that stimulate the highest levels of opioid release in the brain. Heroin increases opioid levels hundreds of times more than sugar does. Therefore a person who is suffering enough to cling to the relief provided by heroin is very unlikely to get hooked on something as comparatively weak as sugar.

This is not to say that sugar addicts are completely nonexistent. As I said above, people can get hooked on anything that offers pleasure or relief. But insofar as sugar addiction is real, sugar itself is not to blame. Anti-sugar crusaders often claim that sugar causes depression, but the scientific evidence suggests they’ve got it exactly backwards: people living in psychic pain are likely to eat more sugar—and more of a lot of other things besides sugar. Indeed, newer research indicates that any food that tastes good may stimulate opioid release and reconfigure the brain’s reward circuitry in a manner that modifies future behavior. Among the overweight people I know, most would appear to have greater weaknesses for fat and salt than they do for sugar.

Getting back to alcohol, I’d like to point out that drinking alcohol in moderation is one of the healthiest habits a person can have. Moderate drinking reduces the risk of heart disease and diabetes, lowers markers of systemic inflammation, and even increases lifespan. The University of Cambridge Medical Research Council included moderate alcohol consumption on a selective list of four behaviors that collectively increase lifespan by fourteen years. The other three were not smoking, exercising regularly, and eating five servings of fruits and vegetables a day.

Is alcohol a toxin? Yes! Plenty of things that are toxic in excess are healthy in moderation. Nutrition scientists now believe that most antioxidants in plant foods are toxins. They enhance cellular health by provoking a stress response. So it’s a bit rash to look at the negative consequences of consuming large amounts of sugar over a prolonged period of time and conclude that no one should ever consume any sugar.

Millions of years ago, fruit was the most energy-dense food in the diet of our primate ancestors, thanks to its sugar content. Without fruit sugar our Neogenic forbears would have had a hard time meeting the energy demands of survival. Today sugar is known to significantly enhance human work capacity by acting on the brain to make physical exertion feel easier. Sugar need not even be ingested to yield this effect—merely tasting it is enough. This is why runners quaff sports drinks during marathons.

Humans like sweet-tasting things for a reason, and we’ve liked them for a long, long time. Seven million years ago we were essentially bonobos, an ape species that has “an incurable sweet tooth,” as one writer put it. Our ancestors evolved this predilection because individuals that had a taste for sugar ate more fruit and thus lived longer and bore more offspring. The pleasure we derive from sweets is a natural genetic inheritance, yet anti-sugar extremists treat it like a biological form of original sin, something to be ashamed of and to repress. By the way, have you tasted human breast milk lately? It’s surprisingly sweet. It contains 54 percent more lactose (“dairy sugar”) than cow’s milk.

Pleasure is not only nature’s way of guiding creatures toward healthy behaviors; it is also intrinsically healthy. Scientific support for this idea is abundant, yet it seems counterintuitive here in America, a society founded by dour religious fanatics and still reeling from their scowling influence. American diet gurus of all stripes are deeply mistrusting of gustatory pleasure. Anti-sugar zealots triumphantly expose sugar’s similarity to cocaine vis-à-vis its action on opioid receptors as though this were the most damning charge that could possibly be leveled against a nutrient. Well, guess what else stimulates opioid release in the brain? Laughter, exercise, and mother-infant bonding, among other things.

I’ve got an idea for Mark Hyman’s next tweet: Why don’t we just give babies crack if we’re going to allow mothers to hook them on being cuddled and cooed at?!

Chocolate, too, increases opioid levels in the brain and it is well-known to elevate mood state for precisely this reason. This explains why depressed persons eat twice as much chocolate as the average person. But check this out: Chocolate that is modified to be tasteless has no effect on mood state. The taste experience of chocolate is inseparable from its drug-like action on the brain, which is inseparable from its beneficial health effects. Of course, sugar is only a secondary ingredient in chocolate, but sugar-free chocolate is practically inedible.

The pleasure we experience when eating sweets is dismissed by sugar haters as a crude, animal thing, but it can be much more. Some sweets are works of art. If your average candy bar or soft drink is the confectionary equivalent of reality television, a blueberry panna cotta made by a great pastry chef is The Godfather. Enjoying an exquisite chocolate mousse or truffle is a celebration of human creativity and of our species’ uniquely sophisticated relationship with food.

When I was growing up my mother used to make a French silk pie for special occasions. The recipe called for loads of sugar as well as five eggs, each of which had to be whisked for five minutes. I’m not making this up. The result would make your knees buckle. My mom should be sainted for making French silk pie as often as she did, but whoever came up with the recipe deserves a Nobel Prize.

Some members of the anti-sugar faction have suggested that sugar should be a controlled substance, like its “cousin” crack cocaine. I have nightmares about living in an Orwellian dystopia where sugar police—literal sugar police—break down the door of my childhood home and haul my mother off to prison for making French silk pie for my father’s birthday. (Not really.)

Sugar haters constantly invoke science in support of their dogma, but their style of messaging is strikingly unscientific. The typical anti-sugar communication is, like Mark Hyman’s Cinnabon tweet, strident and holier-than-thou. One of the sacred texts of the movement is a YouTube video of a 2012 lecture titled “Sugar: The Bitter Truth,” which was delivered by Robert Lustig, an endocrinologist at the University of California-San Francisco.

“I’m going to tell you tonight a story,” Lustig began, “and by the end of the story I hope that I will have debunked the last 30 years of nutrition information in America!”

This is not the language of a scientist. It is the language of a stage magician, or a circus barker. “Step right up, ladies and gentlemen, and prepare to have your minds blown by the sinister might of Satan’s favorite nutrient: sugar!” Lustig’s tone is theatrical, applause-seeking, and unserious. If I had known nothing whatsoever about nutrition before watching Lustig’s lecture I would have assumed an attitude of extreme skepticism toward everything that came out of his mouth after those introductory words and I would have subsequently looked to other experts to inform my beliefs concerning sugar.

An overreaction? Hardly. Style matters. Scientists who betray obvious signs of wanting to believe what they believe are not good scientists. Compare Lustig’s chest-thumping histrionics to the measured tone of Stephan Guyenet’s delivery in his lecture, “The American Diet: An Historical Perspective,” also available on YouTube. Guyenet’s position on sugar is that we eat too much of it. That’s all. Virtually every nutrition scientist who holds this view expresses it the same way he does—dispassionately—whereas almost everyone who holds the view that sugar should be subjected to some kind of “final solution” expresses it as Robert Lustig does: frothing-mouthed.

One might defend the sugar haters on the grounds that a message as urgent as theirs demands an overwrought delivery. But I think it’s the other way around: the moralistic, browbeating style of the sugar haters’ messaging is symptomatic of an irrational disposition that led them to their over-the-top views on sugar in the first place.

Most of us are not qualified to judge whether science supports this or that position on sugar—or on any other nutritional debate, for that matter. The best we can do is let our gut instincts (so to speak) tell us which scientists to trust. My gut responds favorably to signs of open-mindedness and reason, which I see in Stephan Guyenet and in others with a moderate take on sugar. But I have known other folks who cannot resist the godlike certitude of a Mark Hyman or a Robert Lustig.

In the specific case of sugar, though, there is something else that we nonscientists can go by, and that is personal experience. I’m sure there are many people who have been easily persuaded that sugar is addictive and toxic because they eat sugar by the shovelful and their health is terrible. But many others have been so persuaded even though their experience with sugar is like mine, lacking any evidence of dependence or consequence.

I’m not suggesting that these eager victims of dietary brainwashing are stupid, or that their indoctrinators, the likes of Mark Hyman and Robert Lustig, lack intelligence. But the argument that sugar is addictive and toxic in any amount is utterly fatuous. Why do smart people entertain such a silly belief? Well, smart people believe all kinds of silly things, but food is a unique case. Humans have a special susceptibility to form irrational beliefs about food, and also to irrationally demonize foods that are perfectly okay to eat, if only in small amounts.

Mankind is nature’s ultimate omnivore. But we weren’t always. The story of Man is a story of dietary diversification. Throughout our existence we have made a habit of eating things we have never eaten before. Sometimes a new food we tried really was toxic and was subsequently declared taboo. As time went by, though, individual cultures began to make taboos of foods that were not toxic, merely for the sake of defining themselves as distinct from other cultures. Hence the ancient Jewish prohibition against eating meat and dairy in the same meal, which was originally a prohibition against eating a specific sacrificial dish of a rival religion.

Things aren’t so different today. Nearly all popular diets present themselves as rationally focused on health. Yet most of them demonize foods or nutrients that are health-enhancing (as strict vegetarians do, for example, with fish) or else they greatly exaggerate the harmfulness of foods or nutrients that are best consumed only in small amounts (as the sugar haters do with sugar). Those who create and enforce these taboos have no more idea why they’re really doing it than my dog Queenie has as to why she humps my leg, but I’m telling you why: instinct. There exists within the human breast an ancient impulse to forge community bonds with people who refuse to eat what we refuse to eat and to condemn those who eat what we refuse. This impulse runs so deep that, according to studies by Yale psychologist Karen Wynn, infants as young as six months of age exhibit a desire to punish puppets that seemingly don’t share their food preferences. It takes a special effort to resist this impulse and to think rationally about diet, an effort that many of us lack the wherewithal to make.

This “diet cult” instinct, as I call it, is wonderfully allegorized in the story of the forbidden fruit, which, in case you’ve forgotten, is to be found on page one of your Bible. God tells the first human, Adam, “Of every tree of the garden you may freely eat: But of the tree of the knowledge of good and evil, you shall not eat of it: for in the day that you eat thereof you will surely die.” Adam eats the sweet fruit anyway, but he does not die. He lives, according to scripture, another 930 years.