Researcher who found that high-fat foods cause damage to the hypothalamus — an area of the brain that controls your urge to eat and sends signals to stop eating when you're full — in rodents have linked their research to obesity in humans.
The study was published recently in The Journal of Clinical Investigation and bears the opening statement: "Obesity has emerged as a major health problem in industrialized nations."
About a third of Americans are obese, according to the Centers for Disease Control and Prevention.
MyHealthNewsDaily.com, reporting on the new research, wrote that comparison of rats and mice that ate a high-fat diet with those that ate a regular diet found gliosis — an overgrowth of cells that is a sign that the brain has tried to heal itself from injury — in the former group.
They also found that though the brain's repair effort was effective, inflammation and gliosis persisted as long as the animals remained on a high-fat diet.
Moreover, the brain images of 34 healthy people, who ranged from lean to obese, revealed a link between body weight and gliosis similar to what was found in rodents.
The site quotes study co-author Dr. Joshua Thaler, an endocrinologist at the University of Washington, as saying: "There seemed to be more gliosis in people who were obese than those who were lean."
Thaler speculated that obesity might also be linked with inflammation in the hypothalamus, which "may prevent it from responding to hormones like insulin that regulate our body weight."
CNN cites the study's lead author, Dr. Michael Schwartz, also an endocrinologist at the University of Washington School of Medicine, as saying the work represented a step in the right direction for obesity treatment.
The human body is designed to regulate how much fuel is stored as fat through a process called energy homeostasis, the study's lead author Dr. Michael Schwartz says. For a normal-weight person, that's good. But once a person becomes obese, his or her body seems to want to stay at that new weight permanently.
"That's the biggest problem with obesity treatment," Schwartz reportedly said. "Obese people can lose weight, but they have trouble keeping it off."
CNN also quotes Dr. Steven R. Smith, co-director for the Sanford-Burnham Diabetes and Obesity Research Center, as saying that while researchers must first determine if the scarring happening in the rodent models will translate to the human condition:
"These are really important papers that begin to push the idea out that we're not in control as much as we think we are."