I think we may have suspected this for quite some time now … yet we keep handing out Happy Meal vouchers as prizes and rewards for school kids. “Happy” indeed.
Junk food turns rats into addicts
Bacon, cheesecake and Ho Hos alter pleasure centers in rats’ brains
By Laura Sanders
Science News Online
CHICAGO — Junk food elicits addictive behavior in rats similar to the behaviors of rats addicted to heroin, a new study finds. Pleasure centers in the brains of rats addicted to high-fat, high-calorie diets became less responsive as the binging wore on, making the rats consume more and more food. The results, presented October 20 at the Society for Neuroscience’s annual meeting, may help explain the changes in the brain that lead people to overeat.
“This is the most complete evidence to date that suggests obesity and drug addiction have common neurobiological underpinnings,” says study coauthor Paul Johnson of the Scripps Research Institute in Jupiter, Fla.
These reward pathway deficits persisted for weeks after the rats stopped eating the junk food, the researchers found. “It’s almost as if you break these things, it’s very, very hard to go back to the way things were before,” Kenny says. When the junk food was taken away and the rats had access only to nutritious chow (what Kenny calls the “salad option”), the obese rats refused to eat. “They starve themselves for two weeks afterward,” Kenny says. “Their dietary preferences are dramatically shifted.”
Scientists are interested in determining the long-term effect of altering the reward system. “We might not see it when we look at the animal,” says obesity expert Ralph DiLeone of Yale University School of Medicine. “They might be a normal weight, but how they respond to food in the future may be permanently altered.”
–complete article here