A study making headlines today purports to conclude that Oreo cookies are “just as addictive as cocaine.” If a scientific study showed that a popular snack food had the addictive properties of a narcotic substance, popular press headlines would be appropriate. The study in question plainly does not support that conclusion, however.
The researchers conducted the study as follows:
On one side of a maze, they would give hungry rats Oreos and on the other, they would give them a control – in this case, rice cakes. . . . Then, they would give the rats the option of spending time on either side of the maze and measure how long they would spend on the side where they were typically fed Oreos.
. . .
They compared the results of the Oreo and rice cake test with results from rats that were given an injection of cocaine or morphine, known addictive substances, on one side of the maze and a shot of saline on the other. Professor Schroeder is licensed by the U.S. Drug Enforcement Administration to purchase and use controlled substances for research.
The research showed the rats conditioned with Oreos spent as much time on the “drug” side of the maze as the rats conditioned with cocaine or morphine.
From these two independent tests, it only seems possible to draw two independent conclusions: 1) rats like Oreos more than rice cakes, and 2) rats like cocaine or morphine more than saline. Plainly, because the testing did not directly compare Oreos and cocaine, it would be inappropriate to draw a conclusion that directly compares Oreos and cocaine.
From these two, independent tests, we do not know whether rats prefer Oreos in equal measure, for example, to cocaine. One seemingly easy way to find out would have been to ask them directly to choose between Oreos and cocaine, and it is strange that the researchers did not conduct such a test.
The testing conducted also appears to conflate preferentiality with addictiveness. Establishing that “hungry rats” consistently prefer one type of food over another does not necessarily mean that they are addicted to the preferred food option. The addictive force in a person would seem to be stronger than and fundamentally different from a mere preferential force; indeed, the power of addiction is that it can compel a being to act against its preferences in order to serve the addiction.
All we know from this research is that hungry rats would rather eat Oreos than rice cakes, not that the Oreos were “addicting” in a non-colloquial sense. A behavioral test for Oreos’ addictive properties might be whether rats choose Oreos over other, equally or more desirable food, or whether they eat Oreos even when they are not hungry, or otherwise consume Oreos to their detriment.
Addiction surely has a neurological component as well, but again, the difference between preference (or pleasure) and addiction (or need) would seem to be important. In follow-up research, one of the student-researchers conducted some neurological testing:
They used immunohistochemistry to measure the expression of a protein called c-Fos, a marker of neuronal activation, in the nucleus accumbens, or the brain’s “pleasure center.”
“It basically tells us how many cells were turned on in a specific region of the brain in response to the drugs or Oreos,” said Schroeder.
They found that the Oreos activated significantly more neurons than cocaine or morphine.
“This correlated well with our behavioral results and lends support to the hypothesis that high-fat/ high-sugar foods are addictive,” said Schroeder.
That we derive more pleasure from consuming Oreos than from consuming cocaine or morphine is interesting, but it does not necessarily mean that consuming Oreos creates the pervasive neurological shift that constitutes addiction. (This is probably why the researchers only describe a “correlat[ion]” on this point.)
As someone without formal neuroscience training, my assessment of this study and the conclusions drawn from it certainly may be incorrect, but my criticism seems obvious, appropriate, and easily addressed (and remedied, if necessary). I do not mean to suggest that this Connecticut College group is the only scientific research team susceptible to this critique, as the popular science news contains plenty of examples. Maybe something that seems obvious– Why not compare Oreos and cocaine directly?– to a lay reader like me would never occur to the trained researchers because it is not a scientifically relevant inquiry. If the scientific community wants to present its work to a popular audience, however, it should shed the thin veneer of social justice concerns, which the Connecticut College group attempted to apply, and focus on addressing that audience’s natural curiosities, which are particularly likely to arise in response to sensational headlines like “Oreos as ‘addictive as cocaine.’”