Have you ever been attracted to a food that you knew was not good for you? Did you ever dig into a greasy burger, a triple-cheese pizza, a candy bar, or double-chocolate cake, knowing that they could affect your weight or clog your arteries?
Of course. We’ve all been there. Even when we know that some foods are not doing our bodies any favors—maybe even especially when we know they are bad for us—we are like moths to a flame.
Why does that happen? It is perhaps the single most important question we could ask. Sometimes understanding the facts about what can destroy or protect the brain is not enough to motivate us to action, and we need more incentives to eat right.
The fact is, a war is going on inside your brain, and one small part of your brain is winning. Its weapon is dopamine. It can kill your resolve to stay healthy, and it may end up killing you. Let’s take one last trip to England, where we’ll spot the problem.
Just as the Beatles hit the peak of their popularity, the drug culture was exploding. In San Francisco, New York, London, and everywhere else, marijuana, hallucinogens, cocaine, and heroin were becoming widely available for the first time, and society was trying to sort out how to deal with them.
Musicians seemed especially vulnerable to the deadly effects of drugs and alcohol. Jimi Hendrix, Janis Joplin, Jim Morrison, and Rolling Stones guitarist Brian Jones were all part of the so-called 27 Club, named for their age at death. “We were smoking marijuana for breakfast,” John Lennon said in a 1980 interview.1 “We were well into marijuana and nobody could communicate with us, because we were just all glazed eyes, giggling all the time. In our own world.” Cocaine, LSD, and alcohol all came along, too.
Now, a key part of a manager’s job is to fend off drugs, alcohol, and any other threat to success, or at least to try to contain them as much as possible. After all, if the band stops showing up for gigs or cannot make it through a performance, the game is over.
But Epstein—the forward-thinking, exquisitely organized planner who always seemed to know the best path forward—did not stop the Beatles’ drug use. He couldn’t, because he was pulled into the world of drugs himself.
Perhaps it was inevitable. Drugs were everywhere in the music business at that time. Moreover, Epstein pushed himself to the absolute limit. Most people would have been satisfied to be managing the most successful musical group in history. But Epstein simultaneously took on another Liverpool group—Gerry and the Pacemakers—and guided them to stardom with “Ferry Cross the Mersey” and many other hits. He also managed Billy J. Kramer and the Dakotas and Cilla Black, merged with the management company that handled Cream, the Who, and the Bee Gees, launched a theater, and took on endless other projects. For a young man who had fallen into the music business by taking a job in his parents’ furniture store’s record department, success came dizzyingly fast. Drugs became a coping mechanism. Epstein fell into amphetamines, marijuana, and barbiturates, experimented with heroin, and sometimes drank more than was good for him.2
On August 27, 1967, Brian Epstein did not answer his phone. A knock on his apartment door elicited no response. His live-in assistant broke open his bedroom door and found his pulseless body lying on his bed. The medical examiner took blood samples, which revealed Carbrital, a barbiturate.
This was not a suicide. Barbiturates had been Epstein’s way to turn off his brain and get to sleep, and over time it took more and more to shut out the day’s events.
So 1967 did not bring us a picture of the sober manager who reined in the rowdy rock band and kept them on the straight and narrow. Epstein was drawn into the world of drugs and was ultimately destroyed by them.
If drugs are so deadly—if they can get you into trouble with the law, destroy your relationships, ruin your career, and maybe even kill you—why do people take them? The reason is dopamine.
Deep inside your brain, in what is called the reward center, dopamine waits in tiny round vesicles inside brain cells. Dopamine is a neurotransmitter. That is, it is a natural chemical that carries messages from one brain cell to another. It is actually waiting for you to find something to eat—some really good, tasty food. As soon as you do, dopamine bursts out from one brain cell and races across the gap to give the news to a neighboring cell. Other brain cells follow suit—one cell squirting dopamine at the next, all of which creates a little party in your brain and a feel-good sensation for you.
Your brain is not doing this just for fun. Your brain uses dopamine to make sure you remember the sights, sounds, and smells of this happy event, so that you’ll come back and do the same tomorrow. After all, food keeps you alive. Dopamine resets your priorities to make sure that whatever else you might have had on your schedule—battling a neighboring clan, planting a garden, flying to the moon, or whatever—it will all come second to whatever got your dopamine flowing. Dopamine organizes your to-do list.
If this sounds odd, it is important to remember that for much of our time on Earth, food was not just sitting at the corner grocery store. You had to go out and find it, and you had to be able to separate what was nourishing from what was poisonous. And so the reward center has been part of the mammalian brain since long before the dawn of our species. Our biological cousins use it, too. At Gombe, on the shores of Tanzania’s Lake Tanganyika, Jane Goodall observed chimpanzees digging into the succulent strychnos fruit. As the juice dripped down their chins, you could almost see the dopamine sparks in their brains.
Your reward center is also keen on sex. No, sex doesn’t keep you alive, but it goes a long way toward keeping the species alive, so it has gotten favorable treatment as evolution shaped our brains.
So your reward center is looking for food and for a receptive mate, and when it finds them, out comes the dopamine. But this primitive system can be hijacked by drugs. A whiff of marijuana, a snort of cocaine, a shot of heroin, and, in fact, virtually all drugs of abuse trigger the release of dopamine. The same is true of a glass of wine, a cigarette, and a cup of coffee. Whatever else they do in your brain—calm you down, pick you up, create hallucinations, ruin your driving, or anything else—they also trigger dopamine. That’s why people use them. The market for legal and illegal drugs depends on a flaw in the human brain: Its dopamine switch is easily manipulated.
Drugs are much more potent at triggering dopamine compared with foods or sex, which is why addicts often lose interest in food, sex, and more or less everything else in favor of their drug of choice. But food manufacturers found that they could play that game, too. The dopamine release that you get from an apple, an orange, or a strychnos fruit is actually pretty modest. So, over time, the food industry has learned how to enhance it, making products that are less and less like food and more like drugs.
Exhibit A: sugar. Yes, an apple or an orange is pleasantly sweet, and it tastes very nice on a hot summer day. But why stop there? By extracting and purifying the juice from sugarcane or sugar beets, sugar companies get pure, concentrated sucrose—table sugar. And sugar is a hit. We bake it into cookies, pies, and cakes, and give it to children to show our “love.”
In the brain, sugar stimulates the release of mild opiates—that is, natural compounds that are in the same chemical class as heroin and other narcotics but much weaker. You probably already know of some of the opiates the brain creates—the natural endorphins that cause the “runner’s high” that marathoners experience. Sugar also stimulates the release of dopamine.
Exhibit B: chocolate. In prehistoric Central America, Aztecs turned cacao beans into a warm drink they called chocolatl. It was bitter, and neither they nor the early Spanish explorers saw much commercial potential in it. But in the mid-1800s, chocolate manufacturers discovered that by extracting and concentrating cocoa butter and then combining it with cocoa powder, sugar, vanilla, and other flavorings, chocolate becomes irresistible. Dopamine receptors light right up.
Exhibit C: cheese. Cows produce milk for one reason: to nourish their young. But about ten thousand years ago, some adventurous humans decided to taste cow’s milk themselves. In your digestive tract, milk’s casein protein breaks apart to release mild opiates, called casomorphins. They are not produced by your brain cells. They are actually in the milk protein that nature meant for the rapidly growing calf, and as you digest it, the opiates are released and absorbed into your bloodstream. In turn, these opiates trigger dopamine release.
Later on, someone figured out that coagulating milk and expressing out the water transforms it into cheese. And now we’re on to something. Cheese has concentrated casein and so delivers a much larger casomorphin dose. It may smell like old socks and have more saturated fat, cholesterol, and sodium than a steak, but people flock to the cheese counter to get their hit of opiates and dopamine.
Exhibit D: meat. Humans do not have the long canine teeth that natural carnivores like cats and dogs use to kill and dismember prey. At least three and a half million years ago, our ancestors’ canine teeth withered away to be no longer than their incisors. So while we were pretty handy with fruit, leaves, nuts, and anything else we could pick with our fingers and opposable thumbs, dismembering a mastodon was not really in the cards. Then, when the Stone Age brought us hatchets, arrowheads, axes, and knives, we finally were able to eat like carnivores. Never mind that we still have pre–Stone Age bodies that develop heart disease and colon cancer in response to meat eating. Meat, like sugar, chocolate, and cheese, has an opiate effect in the brain, which in turn triggers dopamine release. Researchers have shown that when people are given a drug that blocks opiate effects in the brain, they lose much of their interest in meat.3
So let’s come back to the question that started us off: Why do we eat foods that we know are not good for us? Because they bathe our brains in dopamine. And dopamine won’t take no for an answer. It glamorizes every last detail of whatever triggered it—the sweetness of sugar, the sizzle of a steak, and even the moldy smell of cheese.
Look at a wine connoisseur. At one point in his life, wine was not important to him. The first bitter taste might even have been a bit off-putting. But alcohol triggers dopamine, which embellishes every aspect of the drink that delivered it. He no longer speaks of how a wine smells; it now has a “bouquet.” The color of the wine, its taste, its aftertaste, and the feel of the stem of the glass between his fingers—all engender glowing poetry, because they have been wildly oversold by dopamine.
Dopamine gets you into trouble. Up until now, good health, a long life, and a trim figure might have been high on your list of priorities, but chocolate, burgers, and cheese pizza elbow their way ahead of them. Have a candy bar—or two or three, your reward center tells you. Don’t worry, just enjoy it, it insists.
So where is your Brian Epstein in all of this? Where’s your internal manager who is supposed to talk you out of things you’ll regret later? Unfortunately, dopamine got him, too. In fact, your cerebral cortex is recruited to help support the addiction. You’ll find yourself coming up with increasingly far-fetched rationalizations for why you ought to set aside caution. “I can exercise those calories off,” your now-corrupted brain tells you. “Everything in moderation,” “My grandfather ate all the wrong things and lived to be ninety, so how bad can it be?” and so on. Your priorities have been reset, and your entire brain has been recruited to embrace the culture of dopamine.
There are certain times when you’ll be especially susceptible to dopamine’s siren call. When you are stressed, angry, lonely, or tired—when the world has treated you badly—you are not likely to look for solace in healthful foods. No one ever went to a convenience store at nine o’clock at night to buy cauliflower. That’s when we turn to sugary cookies, chocolate bars, cheesy pizza, greasy burgers, or other junk food. We call them “comfort foods,” because that is exactly the effect opiates and dopamine provide.
Some people are vulnerable for a different reason. Their genes conspire against them. During a research study on diabetes, I found that while some people changed their diets easily, others had a tougher time, and I wondered whether genes might explain this difference. It was already known that we all have a gene called DRD2—dopamine receptor D2—that is involved in building the receptors for dopamine. These receptors are like little docks on the outside of each cell, ready to receive the latest shipment of dopamine as it arrives. One variant of this gene causes you to have about one-third fewer dopamine receptors. And with fewer receptors, you do not get the same “feel-good” sensations other people get from dopamine. You would need an extra amount of dopamine just to feel normal. So you could end up being drawn to alcohol, smoking, drugs of abuse, and even risk-taking behavior, all of which give you an extra dose of the dopamine you are missing. About one in five people carries this genetic trait.
I took blood samples from each of our participants and sent them to the University of California at Los Angeles, where Ernest Noble, MD, extracted their DNA. A short time later, Dr. Noble called me on the telephone. He had found that nearly half of our diabetes patients had the gene variant that caused them to have too few dopamine receptors.4 That was far higher than the normal one-in-five prevalence of this genetic trait. Moreover, when we tracked how our patients did over time, those with the gene for too few dopamine receptors did not respond as well to a healthy diet—they did not improve as much—compared with people who had the normal number of receptors, presumably because they had more trouble with cravings and lapses.
I began to suspect that many people overeat in order to get dopamine stimulation. They are not aware of what is happening inside their brains, but they are drawn to food, especially unhealthful foods—more so than other people. They find it hard to break away. And when overeating gets into high gear, it leads to obesity, diabetes, and myriad other problems, including a higher risk of brain disorders.
If you are thinking you might like to be tested to see if your own food cravings could be due to a genetic trait, it is important to understand that anyone can fall victim to the addictive power of foods, no matter what genes you carry. Food manufacturers are doing everything they can to seduce your taste buds and keep you in a state of constant temptation with displays of food products in stores, gas stations, and airports and on television. They can easily overpower your inner manager, and they know it.
So am I saying that weight problems and diabetes are caused by dopamine? Yes, in part. And the same is true for heart disease, high blood pressure, and every other condition related to food, including Alzheimer’s disease and stroke. In all of these conditions, the drive for dopamine draws you to the very foods that can hurt and kill you. It is dopamine that pushes you in front of the train.
Now, let’s not be overly simplistic. Other genes play important roles in our disease risk, too, and even if you were on a perfect diet, you could still have health problems. Life is not fair. But eating healthfully goes a long way toward preventing health problems, and it is increasingly clear that there is a reason why unhealthful foods attract us. That reason lies deep inside our brain cells in tiny vesicles filled with dopamine.
Is there a healthy way to get dopamine? Can we get a little bit of “feel good” without drugs, booze, or junk food? Well, I thought you’d never ask!
There actually are a couple of ways. First, you can break a sweat. Exercise releases mild opiates—endorphins—and also appears to trigger the release of dopamine. If you were to get up in the morning and have a half-hour run or a brisk walk, the natural feel-good sensation that comes from exercise would make you less likely to turn to unhealthful foods later in the day.
Second, there is a role for intimacy. If food is your preferred form of “comfort,” it’s time to have real comfort, which comes from developing friendships, engaging in conversations, intimacy, sexuality—any or all of the varieties of personal interaction.
But let’s think beyond dopamine. Forty years before the Beatles and eight hundred miles away, Sigmund Freud wrote about the Beatles and Brian Epstein. He did not use their names, of course; they had not yet been born. But Freud described the unruly drives that well up from deep and primitive brain structures. For Freud, those scruffy, fun-loving, irresponsible, troublemaking desires were the id. And the manager—the more mature, forward-thinking part of ourselves—was the ego. The ego’s job, like Epstein’s, was not to frustrate the id. It was to help the id succeed. The ego makes plans, keeps you on schedule, and maintains the long view.
But the ego has limits, too, as Epstein illustrated so tragically. Freud wrote that there is a third brain function, called the superego. The superego is not there to manage your primitive drives. It looks beyond them, and helps you see the bigger picture around you. When you aspire to do good in the world, setting aside your own desires—that’s the superego in action. And when you feel guilty about having let someone down, that’s the superego, too. It is the part of you that thinks about others.
The ego—your manager—is not a particularly high-minded soul. The truth is, it just wants its percentage. That is, it helps you negotiate your world more effectively, and you’ll both be better off. The superego is something else entirely. It looks at the needs of the world around us.
That broader view can save your life. It can provide the motivation you need to break away from unhealthy habits. Sir Paul McCartney described exactly this as he recalled looking out the window at his farm in Scotland. He was sitting with his wife Linda.
We were eating roast lamb for Sunday lunch and it was the lambing season and there were all these beautiful little lambs gamboling around. Then we just looked at the lamb on our plate and looked at them outside again and thought “we’re eating one of those little things that is gaily running around outside.” It just struck us, and we said “Wait a minute maybe we don’t want to do this.” And that was it, that was the big turning point and we said we’d give up meat.5
This change of heart did not come from any sort of drive or ambition. This was not the id talking. Nor did it come from a manager prescribing a good career move or health advice. Paul and Linda began to consider the world around them. And then they realized how food choices affected their children, too.
It was all brought into focus by our youngest daughter Stella coming home from school one day and saying how they’d been having this debate about eating meat and she said, “Mum, when we were talking about it I had a really clear conscience.”
For most of human history, we did not need any dietary directives from our superego. Junk food simply was not available. We did not have an easy way to extract sugar from sugarcane or sugar beets, or to turn cacao beans into Snickers bars. Cheese hadn’t been thought of, and meat eating, while not impossible, was arduous enough that steakhouses and chicken restaurants just were not a winning proposition. And when these products became available, it was a long time before they were inexpensive enough to be as ubiquitous as they are nowadays.
Today technology has removed those barriers. Junk food is cheap. We can have it anytime we want it. It calls to us from every corner, and that’s where we run into trouble.
So I have two suggestions that are designed to help your ego and superego tackle that scruffy id of yours:
Set some rules. If you are having trouble resisting any unhealthful food, whether it’s a greasy cheese sandwich, a chicken wing, or a sugary snack, you’ll find it easier to set it aside completely than to tease yourself by having it occasionally. This is the opposite of what many people imagine. “Maybe I can just have it now and then,” we say to ourselves. “A little bit won’t hurt.” And in theory, that’s true. The problem is that each dose of a problem food triggers another dopamine blast that reinforces the desire for it. Each bite makes it harder to say no next time. By setting it aside—even for just a couple of weeks—we’re able to forget about it a bit once we get over that initial craving hump.
If that sounds like tough love, it’s exactly the lesson that smokers learned a long time ago. Quitting is not easy, but it is much easier than teasing yourself with an occasional cigarette. “Moderation”—for both cigarettes and junk food—is simply a way of stoking a fire rather than letting it go out.
Look to other motivators. Many people break the meat habit, not for themselves, but because they view factory farming and animal transport and slaughter as something they want no part of. Today Americans eat more than one million animals per hour. Even in my grandfather’s day, it was not a remotely kind process, and today it is all the more miserable for all concerned.
Others are moved by reports of the environmental damage that modern factory-style farms engender. From the pesticides used to grow feed crops and the fecal output of chickens, hogs, and cattle that contaminate waterways, to the greenhouse gases emitted by the 100 million or so cattle grazing on American farms, raising livestock is no treat for Earth. These facts are motivating more and more people to change their diets.
One of the most common reasons people decide to take better care of themselves is that their spouses or children depend on them. Not only do we not want to burden our families if we become ill, we want to be there to help them through whatever problems they may encounter. We cannot afford to take risks with our own health that could mean abandoning them. And the more we model healthful habits, the more we help them to do the same.
Whatever your motivation for rethinking the contents of your plate, you will get a huge reward in the form of better health. And that will help you put dopamine in its place.
Now you know the secrets for keeping your brain and physical being well for a long and productive life. There are many recipes to sample, new tastes and new restaurants to try, and many things to explore.
I wish you the very best of luck, and I hope you will share what you’ve found with others.