In a new research our worst fears are confirmed – fatty, fried and fattening foods are addictive. The addiction with these delicious ‘yummies’ may be as potent as that with cocaine or heroin. The study was conducted on experimental animals, rats in this case. When fed with fatty foods in great quantities these rats showed a compulsive need to eat.
According to Paul J. Kenny, Ph.D., an associate professor of molecular therapeutics at the Scripps Research Institute, in Jupiter, Florida these drugs and fatty foods both stimulate the “pleasure centers” of the brain causing the compulsion to repeat the experience. Eventually these transient pleasures “crash” and the drug or in this case food is needed to feel normal.
“People know intuitively that there's more to [overeating] than just willpower," he says. "There's a system in the brain that's been turned on or over-activated, and that's driving [overeating] at some subconscious level."
The study published in a journal, Nature Neuroscience involved studying three groups of laboratory rats for 40 days. One group was fed regular food. Second was given fat rich foods like bacon, sausage, cheesecake, frosting, and other fattening, high-calorie foods only for one hour each day. The third group had unlimited access to these unhealthy foods for up to 23 hours a day.
Obesity in the third group was a known outcome. But what was not anticipated was their change in behavior. 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.
Their eating behavior turned compulsive with even pain stimulus not deterring them from food. These rats were given minor electric shocks on their feet pads. The rats in the first two groups were scared to reach for food in face of such a painful stimulus but the third group were not,
"Their attention was solely focused on consuming food," says Kenny. He also said that similar behaviour is seen when experiments are conducted with cocaine or heroin.
When these high calorie foods were stopped this group of obese rats went on without food for two weeks. This behavior was also linked to their addition.
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. He says that just like cocaine that was initially made from coca leaves and has been distilled to its present state where it can be smoked or inhaled, food is similarly processed from its primitive form.
"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.
Role of Dopamine a chemical in the brain is emphasized in addiction in humans and animals. The study has found that a drop in dopamine receptors in brain of obese rats is similar to that in humans who are addicted to drugs or are obese.
Wang also says that the results of this study conducted on animals may not always be applicable to humans.
"You can't mimic completely human behavior, but [animal studies] can give you a clue about what can happen in humans," Wang says.
However Kenny says that drug development for de-addiction may have a potential role in obesity and compulsive overeating. With obesity and related complications lead to an annual expenditure of $150 billion with nearly two thirds of American adults and one third of children are obese or overweight this might open new avenues for research and not just a new warning to all compulsive eaters.