Food Addiction and Drug Addiction is really the same thing
Having spent most of my life as both a pharmacist and a nutritionist, I have yet to meet a patient who enjoys being addicted to drugs or compulsive overeating.
Why would anyone continue to use recreational drugs despite the medical consequences and social condemnation? What makes someone eat more and more in the face of poor health?
One answer is that modern humans have designed the perfect environment to create both of these addictions.
No one will ever be shocked to learn that stress makes people more likely to search for solace in drugs or food (it’s called “comfort food” for a reason). Yet the myth has persisted that addiction is either a moral failure or a hard-wired behavior–that addicts
are either completely in command or literally out of their minds. Now we have a body of research that makes the connection between stress and addiction definitive. More surprising, it shows that we can change the path to addiction by changing our environment.
Neuroscientists have found that food and recreational drugs have a common target in the “rewards circuit” of the brain, and that the brains of humans and other animals who are stressed undergo biological changes that can make them more susceptible to addiction.
Consider the opioid epidemic. It was estimated that in 2016, 2500 Canadians died of drug overdoses, the largest increase in our history. British Columbia, alone, is on track for 1700 opioid deaths this year because of their large indigenous population. A recent study at the University of British Columbia demonstrated that middle-class whites have experienced an alarming increase in midlife mortality since the 1990’s, driven largely by “deaths of despair” involving suicide, alcohol and drugs. These addicts did not suddenly lose their moral fibre. Instead, they faced poor job prospects, a steady erosion in their social status and, consequently, mounting stress.
In a 2010 study, Diana Martinez and colleagues at Columbia scanned the brains of healthy controls and found that lower social status and a lower degree of perceived social support—both presumed to be indicators of stress—were correlated with fewer dopamine receptors, called D2’s in the brain’s reward circuit.
All rewards—sex, food, money and drugs—cause a release of dopamine, which conveys a sense of pleasure and tells the brain something like: “This is an important experience. Don’t forget it!” The reward circuit evolved to help us survive by driving us to locate food or sex in our environment. Today, the more D2 receptors you have, the higher your natural level of stimulation and pleasure—and the less likely you are to seek out recreational drugs or comfort food to compensate.
Dr. Nora Volkow, the director of the National Institute on Drug Abuse, and colleagues, demonstrated this in a study of Ritalin. Healthy non-drug abusing subjects with fewer D2 receptors experienced the drug as pleasurable while those with more found it aversive.
The study also found that people addicted to cocaine, heroin, alcohol and methamphetamines experience a significant reduction in their D2 receptor levels that persist long after the drug use has stopped. These people are far less sensitive to rewards, are less motivated and may find the world dull, once again making them prone to enhance their everyday life.
Drug exposure also contributes to a loss of self-control. Dr. Volkow found that low D2 was linked with lower activity in the prefrontal cortex, which would impair one’s ability to think critically and exercise restraint.
The same neuroscience helps us understand compulsive overeating. Food, like drugs, stimulates the brain’s reward circuit. Chronic exposure to high-fat and sugary foods is similarly linked with lower D2 levels, and people with lower D2 levels are also more likely to crave such foods. It’s a vicious cycle in which more exposure causes more craving.
Dr. Volkow showed that morbidly obese individuals had reductions in their D2 receptors and that the reduction was proportional to their body mass index. The implication of this blunted reward circuit is that they find normal food consumption insufficiently rewarding. At the same time, when exposed to pictures or smells that predict a food reward, they experience more intense cravings than non-obese people. And just like drug addicts, obese people with fewer D2 receptors also show decreased activity in the prefrontal cortex, making it harder to exert self-control.
At this point you may be wondering: What controls the reward circuit in the first place? Some of it is genetic. We know that certain gene variations elevate the risk of addiction to various drugs, alcohol being one of the best examples. But studies of monkeys suggest that our environment can trump genetics and rewire the brain. We may not be able to change our genetics but we can change our environment.
Michael Nader at the Wake Forest School of Medicine showed this in a study of monkeys and cocaine. When monkeys are moved from an individual cage and housed in a group, some become dominant and others assume dismissive roles. For those that became dominant—meaning they get more attention, more grooming and more access to food and treats—this is a positive change. They now have more D2 receptors and are less interested in administering cocaine. But for submissive animals, the group setting is a stressful change, and they respond by increasing their use of cocaine.
Strikingly, the effect of environment is easily reversible: Stress the dominant monkey by returning it to a solitary cage and its D2 receptors will drop—and its taste for cocaine will increase. In other words, simply by changing the environment, you can increase or decrease the likelihood of an animal becoming a drug addict.
The same appears to be true for humans. Even people who are not hard-wired for addiction can be made dependant on drugs if they are severely stressed. Is it any wonder, then, that the economically frightening situation that so many Canadians experience could make them into addicts? You will literally have a different brain, depending on your postal code, social circumstances and stress level.
The last important component of addiction is access. No matter how stressed you are, you obviously won’t become a drug addict unless you are exposed to drugs. The same goes for compulsive overeating.
We have been consuming food for rather a long time without the modern affliction of widespread obesity. In 1990 no province in Canada had an adult obesity rate above 15 percent; by 2015 nine of our provinces had obesity rates of 25 per cent or higher. The lowest rates were in British Columbia and Quebec but not by much, 24 per cent. So what changed in the last 25 years?
Contemporary humans did not experience a sudden collapse in self-control. What happened is that cheap, calorie-dense foods that are highly rewarding to your brain are now ubiquitous. Once you have had a glass of orange juice, you are not likely to be as satisfied with a healthier and less caloric orange that you have to peel.
For most of history, food was scarce, so there was a great survival advantage of eating as many calories as you could when they were available. There was no flourless chocolate cake on the prairies.
Nothing in our evolution has prepared us for the double whammy of caloric modern food and potent recreational drugs. Their power to activate our reward circuit, rewire our brain and nudge us in the direction of compulsive consumption is unprecedented.
The processed food industry has transformed our food into a quasi-drug, while the drug industry has synthesized ever more powerful drugs that have been diverted for recreational use. We extracted opium from the poppy and quickly discovered how to make opiates that are a thousand times more potent and addicting. Not content with just smoking cannabis, we bred super-potent strains of the plant, extracted the active cannabinoids and moved on to dangerous synthetic versions.
Finally, the advertising industry has played a role. Dr. Volkow and her colleagues are now testing how the brain responds to subliminal messages about food and drugs. They believe that drug-addicted and obese individuals are more susceptible to those messages.
Fortunately, our brains are remarkably pliable and sensitive to experience. Although it’s far easier said than done, just limiting expose to high-calorie foods and recreational drugs would naturally reset our brains to find pleasure in healthier foods and life without drugs.
In the meantime it’s worth remembering that we cannot control our genes or the misfortunes that befall us, much less their impact on our brains. Even the most self-disciplined can fall prey to a food or drug addiction under the right mix of adversity and stress.