Food Addiction? Let's Talk Turkey
For gluttons, Thanksgiving is both blessing and curse. Luckily the science of food addiction is half-baked, so forget the fear-mongering and have another piece of pie.
The curse of Thanksgiving is that it is the only holiday that celebrates eating and only eating. Other activities may be optional, but sitting at the table and digging in to turkey, sweet potatoes, pumpkin pie—at least a few bites to please Grandma—is obligatory. For those who have sweet memories of childhood meals filled with harmony and good cheer, the experience is one of simple pleasure, perhaps even the cozy togetherness that the Dutch call gezelligheid. For others, however, family reunions come with unhealthy servings of stress—from mild dysfunctional bickering to marital warfare to domestic violence. And for those of us with addictions, just going home may itself prompt regressive behavior of all types, including relapse.
Indeed, Thanksgiving poses, more acutely than any other day of the year, the question whether food itself can be addictive.
Food addiction is big in the news this year, but the idea itself has been around for at least 30 years. In 1982, Scientific American caused a minor scandal when it made the claim that cocaine and potato chips were equally addictive, thereby being perceived as minimizing the danger of the illegal drug. But in recent years, thanks in part to First Lady Michelle Obama’s anti-obesity crusade and to former FDA Commissioner David Kessler’s influential 2009 book, The End of Overeating, researchers are again comparing the addictiveness of cocaine and junk food—but this time, trying to raise awareness about the dangers of fatty, sweet and salty foods. The junk food industry, Kessler argues, has deliberately formulated its products to create irresistible cravings.
In his book, in fact, Kessler claims that our modern food environment is so artificial—and so unlike that for which Mother Nature evolutionarily prepared us—that it has rewired our brains, producing the current obesity epidemic. While traditional Thanksgiving fare isn’t the engineered ecstasy of say, a Cinnabon, it’s overdetermined feast placed before a brain designed more for surviving famine.
There’s no doubt that, of course, that we live in an artificial world filled with unprecedented types of temptations. But I think we need to be cautious about making such strong claims about the effects of substances on the brain. Founding the idea of food addiction on science—specifically, the neuroscience of alcoholism and drug addiction—is actually tautological.
Claiming that food and sex are addictive because they light up the brain's “drug” regions is absurd; it’s like saying our brains evolved so we could take drugs and these innate addiction pathways are hijacked by artificial drives to eat and reproduce! That’s bass-ackwards.
Here’s why. Originally, researchers argued that during addiction, drugs “hijacked” the brain’s pleasure regions, overstimulating them by inducing higher levels of neurotransmitters than natural rewards like food and sex could produce. But now, they’re arguing that food and sex can overstimulate this system, too. If so, then how so? Some claim that today’s junk food is so intensely processed that it’s essentially a drug, causing a craving unlike any ever seen with foods we ate historically. Others make similar claims about online pornography and sex addiction.
Such claims can’t be proven with the brain imaging studies that are used to support them, however. This is the fundamental problem. Anything pleasurable or desirable will “light up” the brain regions associated with drugs—it wouldn’t be recognized or experienced as “rewarding” otherwise.
Claiming that food and sex are addictive because they light up the “drug” regions is therefore absurd; it’s tantamount to saying our brains evolved so we could take drugs and these innate natural addiction pathways are being hijacked by artificial drives to eat and reproduce! That’s bass-ackwards. In reality, all we know from seeing these images is that experiences of pleasure and desire will activate similar areas. Current technology is still too crude to demonstrate much more than that—the mere presence of activation.
Take the study often cited by supporters of the idea that food addicts and drug addicts have “dysfunction” in the same regions of their brains. As one recent article described the research:
Ashley Gearhardt, devised a 25-question survey to help researchers spot people with eating habits that resemble addictive behavior. She and her colleagues used magnetic resonance imaging to examine brain activity of women scoring high on the survey. Pictures of milkshakes lit up the same brain regions that become hyperactive in alcoholics anticipating a drink, according to results published in the Archives of General Psychiatry in April.
Note the careful language to describe the participants: they had “eating habits that resemble addictive behavior.” In fact, none of the women in the research actually met full criteria for food addiction! The study basically showed that women who liked (chocolate!) milkshakes more, wanted them more. And while it did show some reductions in activation in brain areas associated with putting the brakes on behavior, the researchers didn't test whether participants were actually unable to stop themselves from binging.
Moreover, they didn’t find that these women experienced less pleasure when they drank the milkshakes, as has been found in food and drug addiction.
So, here we have a study presented in the media as showing food addiction in the brain that doesn’t include any actual food addicts! It could be that only actual food addicts show the deadening of pleasure or tolerance that is seen with drugs—but we can't tell that from this research.
In fact, brain-imaging scientists looking at Nobel prizes (or actors looking at Oscars) would probably produce results that look a lot like craving in the brain. That wouldn’t, however, prove that they were addicted to those desired rewards.
And animal research presents similar problems. Early research on the brain’s pleasure centers found that rats would often choose drugs over food and sex—but it wasn’t very careful about what type of food was offered and whether the rats had adequately stimulating environments. As it turns out, in settings where rats can mix and mingle, mate with one another and eat enjoyable foods rather than plain rat chow, they take far fewer drugs.Indeed, when sweet foods or sugar water are offered, rats often prefer them to crack cocaine. Does this mean sugar is more addictive than we thought? Or crack less?
It all depends on what political point you want to use the science to make; the interpretation of the data comes down to your perspective. If you are arguing against sending people to prison for decades for selling crack while junk food merchants make fortunes, play up the junk food (or sugar water). If you are arguing that obesity is going to bankrupt the health care system, play up the crack.
The reality is that addiction isn’t simply a story about whether a particular substance or activity is “addictive.” Addiction is about context, about a relationship between a particular person and a particular culture and a particular substance or activity at a particular time. With even the most addictive substances like crack and heroin, fewer than 20 percent of users get hooked.
Until we take this complexity into account, we will not develop sensible ways of regulating addictive substances and helping people navigate a world in which there will always be some more vulnerable than others—and some sort of addictive escape available to those who want it. We will never eliminate the desire to alter consciousness or the rid the world of technologies to do so.
We’re wired for desire, reward and risk. We need to focus on reducing related harm, not demonizing particular drugs, foods or people. The holidays can only hijack our brains if we believe they do.