Have you ever described yourself as a chocaholic, or blamed your favorite junky snacks for being addictive? Maybe you're not exaggerating.
A study carried out at the Scripps Research Institute in Florida has found that rats show alarming signs of addiction when given junk food.
The study was published in Nature Neuroscience. The scientists involved, Dr. Paul Johnson and Dr. Paul Kenny, set up their research as follows:
- The rats were divided into three groups, with each group being given access to normal, healthy rat food
- One group didn't receive any junk food
- Another group was given limited quantities of junk food
- The third group had unlimited access to junk food
The junk food was described as consisting of bacon, sausage, cheesecake, pound cake, frosting and chocolate.
The scientists also directly stimulated the pleasure receptors in the rats' brains, before the feeding experiment (to establish a base line) and after the rats had been eating junk food:
They found the rats on unlimited junk food needed even more stimulation to register the same level of pleasure as the animals on healthier diets.
This chemical change in the brain's response to pleasure is seen as a hallmark of addiction.
When the rats were cut off from their junk food, they refused to eat at all.
Although this research has been carried out on rats, Dr. Kenny is hopeful that it may point the way towards a clearer understanding of overeating and obesity:
Common mechanisms may therefore underlie obesity and drug addiction. [It is] as far as we know the strongest support for the idea that overeating palatable food can become habitual in the same manner and through the same mechanisms as consumption of drugs of abuse
Could you be addicted to junk food?