I suppose many of us are nodding already. OF COURSE IT DOES. I know what happens to me as soon as I delve into creamy fatty goodness or high-carb deliciousness. Brain - trigger - eat - more please. However with the Extra Benefit of a Gastric Bypass -- I can stop eating. KTHANXRNYPOUCH.
But, does poor eating or overeating cause inflammation in my BRAINS? (Do not answer that.) But I want to know? Did years of overeating and reaching a body weight of 320 pounds screw up my brain?
New (scary) research suggests that the brain is altered by obesity and changes the part of the brain that regulates appetite control and body weight. Perhaps why diets don't work? (For most of us?)
The study was done on rats --
JCI -
Rodent models of obesity induced by consuming high-fat diet (HFD) are characterized by inflammation both in peripheral tissues and in hypothalamic areas critical for energy homeostasis. Here we report that unlike inflammation in peripheral tissues, which develops as a consequence of obesity, hypothalamic inflammatory signaling was evident in both rats and mice within 1 to 3 days of HFD onset, prior to substantial weight gain. Furthermore, both reactive gliosis and markers suggestive of neuron injury were evident in the hypothalamic arcuate nucleus of rats and mice within the first week of HFD feeding. Although these responses temporarily subsided, suggesting that neuroprotective mechanisms may initially limit the damage, with continued HFD feeding, inflammation and gliosis returned permanently to the mediobasal hypothalamus. Consistent with these data in rodents, we found evidence of increased gliosis in the mediobasal hypothalamus of obese humans, as assessed by MRI. These findings collectively suggest that, in both humans and rodent models, obesity is associated with neuronal injury in a brain area crucial for body weight control.
And in readable English, a translation --
NPR -
Now some provocative research suggests that a part of the problem might be that obesity could change the area of the brain that helps control appetite and body weight.
And those changes might start within a day of eating a high-fat meal, according to scientists who are trying to figure out why it's so hard to lose weight. They report seeing changes in the brain after just one day on a fatty diet.
"That was quite a shock," says Michael Schwartz, a professor and director of the Diabetes and Obesity Center of Excellence at the University of Washington. "This might reflect fundamental biological changes in how the brain works that help explain why it's so hard to keep weight off."
He fed rats and mice a high-fat diet, similar to what people in the United States typically eat, and found inflammation in the hypothalamus after just one day, well before the animals gained any weight. They were looking at the hypothalamus because it's the part of the brain that helps regulate body weight and hunger. Earlier studies in obese lab animals have found inflammation there.
Within a week, the animals' brains mounted a defense, activating cells in the brain that repair and protect damaged neurons. The inflammation subsided. But after about a month, the inflammation returned, and continued for eight months, when the researchers ended the study. The results were published in the Journal of Clinical Investigation earlier this week.
Yes, these are animal brains, and human brains might not respond the same way. But Schwartz's team did look at MRI scans done on the brains of 34 people, and found that the people who were obese had more of that repair activity in the hypothalamus than did people of normal weight.
Still, at this point these are just clues as to what might be going on in the brains of people who are obese, and Schwartz is the first to admit that. He's now studying rodents who are switched to a healthful diet after gaining weight, to see if their brains return to normal.
Should we non-rodents be worried? "I would be concerned about this," Schwartz told Shots. "If we can see these responses occurring rapidly with eating high-fat foods in excess, maybe we as humans should think that there are potential consequences for indiscriminate eating."
Not what you want to hear right after a big-eating holiday.
But that spike in inflammation after a pigout could also be a protective response, another scientist says. "My sense is that a lot of it is adaptive," says Rexford Ahima, an endocrinologist at the University of Pennsylvania Perelman School of Medicine. "It may be a good thing."
Ahima co-wrote a commentary on Schwartz's research. He thinks the brain's fast response to fatty food might prove to be normal, like the insulin spike that people get after a big meal. The important brain changes, Ahima speculates, might come when a lab rat has eaten enough to become obese and the brain inflammation is constant.
Whether that also applies to humans who indulge in occasional pigouts, but also overeat day after day, remains to be seen.
Oh.
