Junk food rewires the brain - study

New York - People who binge on fatty sausages, French fries and hamburgers can become as dependent on junk food as a junkie is on drugs, according to a report released by US researchers.

The new study, appearing in the magazine Nature Neuroscience, offers detailed evidence to support previous claims about food addiction.

Scientists from the California-based Scripps Research Institute showed how rat brains changed when they had easy access to high- calorie, high-fat food. The study showed a deterioration in the chemical balance in the circuits of the brain wired for reward.

The study "presents the most thorough and compelling evidence that drug addiction and obesity are based on the same underlying neurobiological mechanisms," said Scripps research associate professor Paul Kenny.

"In the study, the animals completely lost control over their eating behaviour, the primary hallmark of addiction. They continued to overeat even when they anticipated receiving electric shocks, highlighting just how motivated they were to consume the palatable food," Kenny said.

As the so-called pleasures centres of the brain deteriorate and became less responsive, the rats developed compulsive overeating habits and became obese, the study found. The changes in the brains of rats were similar to those in rats which overindulged in cocaine or heroin, the study showed.

Sausage, bacon and cheesecake were among the foods offered to the rats.

"They always went for the worst types of food," Kenny said, "and as a result, they took in twice the calories as the control rats."

The rats refused to eat when offered nutritious, healthy food.

Kenny said that in addiction, the "reward pathways" of the brain become overstimulated and the system turns on itself. The molecular mechanism involved a particular receptor in the brain that plays a major role in vulnerability to drug addiction - the dopamine D2 receptor.

Kenny said the findings of his studies confirmed what many have suspected - that "overconsumption of highly pleasurable food triggers addiction-like neuroadaptive responses in brain reward circuitries, driving the development of compulsive eating." - Sapa-dpa



Source : http://www.iol.co.za