Distinguishing Between Food & Drug Addiction
Research is beginning to uncover that the brain reward systems responsible for making drugs of abuse so addictive are the same pleasure systems that are activated by the foods we eat. While it’s easy to list differences between foods and drugs our brains can have a very hard time differentiating between the pleasure derived from mild doses of some drugs of abuse and some types of food. What are the primary differences between food and drugs of abuse, and how might these differences actually help contribute to food addiction?
Nicole Avena, Ph.D., is a research neuroscientist and an expert in the fields of nutrition, diet, and addiction.
Editor: Saad Shaheed
Drugs of Abuse vs. Food
One of the key differences is that we need food to survive, but we don’t need drugs or abuse. Interestingly, however, the survival value of food is one of the factors that may contribute to its addictive potential. Food is one of our basic needs, and thus our brains are designed to make us enjoy the taste of it and seek it when we are hungry. This explains why some people go to extreme lengths when they are faced with severe hunger (e.g., stealing, cannibalism), which emphasizes what a powerful motivator food can be.
As a species, we need to eat and mate to survive so our clever brains make us enjoy those activities. That enjoyment occurs through the activation of the same reward systems that are activated by drugs of abuse. Drugs of abuse actually “hijack” the primitive brain systems that were put in place to reinforce natural behaviors, such as feeding. Because of this, the brain circuitry is certainly in place for food to also elicit addictive responses.
The fact that food is so readily available makes it easier to binge off of food than it is for drugs. Today in most industrialized countries, food seems ubiquitous. It can be found on every corner block or, if you choose to not leave your couch, you can even have it delivered. Drugs of abuse, on the other hand, are typically less accessible. A third feature that distinguishes the two is the constant exposure we have to delicious and inviting images of food. There are billboards, commercials, and signs everywhere advertising food. Fortunately for drug addicts, the cues associated with drug use are less commonly seen.
Furthermore, there is much more social acceptance associated with overindulgence of food than there is for overindulgence of drugs. You can be arrested, fined, and jailed for buying, selling, and carrying some drugs. You can even be arrested for having an open container of alcohol in your car. There is a social stigma associated with drug use, which is not the case with food (unless this food overindulgence leads to obesity in which case there is a negative stigma). More often than not, people are usually lauded for showing up with food (think about the last time someone showed up at a party with a plate of brownies or brought doughnuts into work).
Food Addiction & The Addicted Body
Comparisons between drugs and food have led researchers to look at studies of “food addiction” as a way to understand why there has been such a sharp rise in obesity rates over the last several decades. The fact that people across the globe are gaining weight rapidly cannot be fully explained by genetic factors or some sort of evolutionary change, as these types of changes don’t happen that quickly. Instead, many suspect that the increase in obesity is due to an environmental change. Our modern-day food environment is filled with opportunities to get quick and easy access to food, which can be a good thing, but unfortunately, these convenience foods tend to be highly-processed, dense in calories, and high in sugars. The ease and convenience of such foods lure us to eat them or feed them to our families, but when they are consumed in excess, body weight increases occur.
Similarities between food and drugs can be seen when comparing someone on an extreme diet and someone quitting some type of drug. Some evidence has shown that quitting carbs and sugars cold turkey may be equivalent to quitting any other drug. The overlaps between drug addiction and obesity have been uncovered, both in terms of behavior and brain changes. For example, studies show that when obese people are shown images of foods they desire, their dopamine system is activated as if one were showing drug stimuli to a drug addict. It doesn’t take scientific studies to tell us this; anyone who is overweight and has gone on a diet in an attempt to lose weight can relate to the overwhelming compulsion and desire to eat certain foods. That is one reason why adherence to diets is so poor.
So when it’s proposed that certain foods with a high concentration of sugar or fast-digesting carbs in them may be addictive, what does this mean? Obviously, humans crave food because we need it to survive, but simply craving sugary, high-carb foods does not mean that we are addicted to them. Humans, especially when very thirsty, crave water, but nobody would claim that anyone has an addiction to water. If you left a person in the desert long enough and offered them water or even just showed them pictures of water, you would probably see a release of dopamine in their brain. Exhibiting this response is not sufficient to say that something is addictive. Addiction is something fundamentally different. How does one cross the line from a user to the abuser to an addict?
Prevalence of Food Addiction
Lots of people try drugs. In the U.S., for example, approximately 50% of adults consume alcohol occasionally. However, only approximately 5% of U.S. adults have been reported to have alcohol abuse. The same pattern is seen for other types of drugs: many may try, but few become addicts. So what is different about food? We are all users of food, and most of us have abused it at one time or another (think about Thanksgiving dinners in your past). But how many people are actually addicted?
There are relatively few drug addicts out there; should we expect the same for food addicts? Probably not. Recent studies suggest that up to 11.4% of normal-weight people may meet the criteria for a diagnosis of food addiction. The numbers are higher among binge-eating disorder patients (up to 40.5% of individuals can be classified as food addicts) and obese patients (up to 57%). These statistics seem extremely high especially when considering that rates of alcoholism fall between 2-8%, but think about this: If drugs of abuse were legal, easily accessible, highly visible, socially accepted, and everyone used them all of the time (as is the case with palatable foods), I bet there would be a lot more people addicted to drugs, too.