A group of students and a professor of neuroscience have discovered that Oreo cookies may be as addictive as cocaine or morphine – to lab rats at least.
Professor Joseph Schroeder and his students at Connecticut College were conducting research on the addictiveness of high-fat and high-sugar foods, and how, for instance, they may contribute to the obesity epidemic.
Prof. Schroeder says:
“Our research supports the theory that high-fat, high-sugar foods stimulate the brain in the same way that drugs do. It may explain why some people can’t resist these foods despite the fact that they know they are bad for them.”
One of the students, Jamie Honohan (who has since graduated with a BA in Behavioral Neuroscience), was particularly interested in human motivation and food, and how the obesity epidemic may be linked to the prevalence of high-fat, high-sugar foods in low-income neighborhoods. It was her idea to use Oreos, as she explains in a statement issued this week:
“We chose Oreos not only because they are America’s favorite cookie, and highly palatable to rats, but also because products containing high amounts of fat and sugar are heavily marketed in communities with lower socioeconomic statuses.”
The results of their study are being presented at the Society for Neuroscience conference that is taking place early November in San Diego, CA.
Measuring pleasurable effects
The study shows that for rats, the association between the pleasurable effects of eating Oreos and a specific environment were as strong as for cocaine or morphine and a specific environment.
For their study, the students gave Oreos to hungry rats on one side of a maze, and on the other side of the maze they gave them a “control” food, in this case, rice cakes (Prof. Schroeder comments that like humans, rats do not seem to relish rice cakes very much).
Then they gave the rats the option to go to either side of the maze (without the food present), and measured how long they spent on the side where they were typically fed with Oreos compared with the side they were fed with rice cakes.
The researchers then repeated the experiment with another group of rats. This time, instead of feeding them Oreos and rice cakes, they injected them with addictive drugs – such as cocaine and morphine – when they were on one side of the maze, or saline, when they were on the other side. (Prof. Schroeder is licensed to carry out this kind of experiment).
The results show that the rats “addicted” to Oreos spent as much time on the side where they had been conditioned with Oreos as the rats that had been conditioned with addictive drugs spent on the drugs side of their maze.
High-fat, high-sugar foods ‘addictive’
Prof. Schroeder and one of the students, Lauren Cameron, furthered the research by measuring the expression of a protein called c-Fos in the pleasure center of the rats’ brains.
“It basically tells us how many cells were turned on in a specific region of the brain in response to the drugs or Oreos,” Prof. Schroeder explains.
They found Oreos stimulated many more neurons than cocaine or morphine. This is in line with the findings of the earlier behavioral experiments and supports the idea that the high-fat, high-sugar foods are addictive.
In 2011, a team from Yale University reported finding that food addiction and substance dependence have similar brain activity.
And finally, one interesting observation – it seems that just like humans, rats eat the middle of an Oreo first.
Written by Catharine Paddock PhD