Sarah Klein wrote an article for CNN, titled “Fatty foods may cause cocaine-like addiction,” discussing recent research co-authored by Paul J. Kenny, Ph.D., an associate professor of molecular therapeutics at the Scripps Research Institute. Here are a few excerpts.
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In the study, published in the journal Nature Neuroscience, Kenny and his co-author studied three groups of lab rats for 40 days. One of the groups was fed regular rat food. A second was fed bacon, sausage, cheesecake, frosting, and other fattening, high-calorie foods–but only for one hour each day. The third group was allowed to pig out on the unhealthy foods for up to 23 hours a day.
Not surprisingly, the rats that gorged themselves on the human food quickly became obese. But their brains also changed. By monitoring implanted brain electrodes, the researchers found that the rats in the third group gradually developed a tolerance to the pleasure the food gave them and had to eat more to experience a high.
They began to eat compulsively, to the point where they continued to do so in the face of pain. When the researchers applied an electric shock to the rats’ feet in the presence of the food, the rats in the first two groups were frightened away from eating. But the obese rats were not. “Their attention was solely focused on consuming food,” says Kenny.
In previous studies, rats have exhibited similar brain changes when given unlimited access to cocaine or heroin. And rats have similarly ignored punishment to continue consuming cocaine, the researchers note.
The fact that junk food could provoke this response isn’t entirely surprising, says Dr.Gene-Jack Wang, M.D., the chair of the medical department at the U.S. Department of Energy’s Brookhaven National Laboratory, in Upton, New York.
“We make our food very similar to cocaine now,” he says.
Coca leaves have been used since ancient times, he points out, but people learned to purify or alter cocaine to deliver it more efficiently to their brains (by injecting or smoking it, for instance). This made the drug more addictive.
According to Wang, food has evolved in a similar way. “We purify our food,” he says. “Our ancestors ate whole grains, but we’re eating white bread. American Indians ate corn; we eat corn syrup.”
The ingredients in purified modern food cause people to “eat unconsciously and unnecessarily,” and will also prompt an animal to “eat like a drug abuser [uses drugs],” says Wang.
The neurotransmitter dopamine appears to be responsible for the behavior of the overeating rats, according to the study. Dopamine is involved in the brain’s pleasure (or reward) centers, and it also plays a role in reinforcing behavior. “It tells the brain something has happened and you should learn from what just happened,” says Kenny.
Overeating caused the levels of a certain dopamine receptor in the brains of the obese rats to drop, the study found. In humans, low levels of the same receptors have been associated with drug addiction and obesity, and may be genetic, Kenny says.
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To read the entire article, click here.
To read some related Situationist posts, see “The Policy Situation of Obesity,” “The Situation of Snacking,” “Big Calories Come in Small Packages,” “The Situation of Eating – Part II,” “The Situation of Eating,” “The Situation of the Dreaded ‘Freshman 15′,” “Our Situation Is What We Eat,” “Social Networks,” “Common Cause: Combating the Epidemics of Obesity and Evil,” “The Situation of Fatness = Our ‘Obesogenic’ Society,” “Innovative Policy: Zoning for Health,” “Situational Obesity, or, Friends Don’t Let Friends Eat and Veg,” “McDonalds tastes better than McDonalds, if it’s packaged right,” “The Science of Addiction, The Myth of Choice,” “The Situation of our Food – Part I,” “The Situation of Our Food – Part II,” “The Situation of Our Food – Part III,” and “The Situation of our Food – Part IV.”
The American obesity paradox is explored at some length by Situationist Contributors, Adam Benforado, Jon Hanson, and David Yosifon, who devoted a sizeable article to the mistaken but dominant dispositionist attributions made regarding obesity and the actual situational sources of the epidemic. To access their article, entitled “Broken Scales: Obesity and Justice in America,” click here.