Eating a High-Fat Diet May Rapidly Injure Brain Cells That Control Body Weight

Obesity among people who eat a high-fat diet may involve injury to neurons, or nerve cells, in a key part of the brain that controls body weight, according to the authors of a new animal study. The results will be presented Tuesday at The Endocrine Society’s 93rd Annual Meeting in Boston.

“The possibility that brain injury may be a consequence of the overconsumption of a typical American diet offers a new explanation for why sustained weight loss is so difficult for most obese individuals to achieve,” said presenting author Joshua Thaler, MD, PhD, a faculty member with the Diabetes and Obesity Center of Excellence at the University of Washington in Seattle.

Thaler and his colleagues studied the brains of rodents for the short-term and long-term effects of eating a high-fat diet. After giving groups of six to 10 rats and mice a high-fat diet for periods from one day to eight months, the researchers performed detailed biochemical, imaging and cell sorting analyses on the animals’ brains.

Within the first three days of consuming a diet that had a similar fat content to the typical American diet, rats consumed nearly double their usual daily amount of calories, Thaler reported. Rats and mice fed the high-fat diet gained weight throughout the study. These rodents developed inflammation in the hypothalamus, the part of the brain containing neurons that control body weight. At the same time, a group of support cells called glia and scavenger cells called microglia accumulated in the hypothalamus and appeared to become activated. Although this collective response to brain inflammation—called gliosis—subsided days later, it recurred after four weeks.

“Gliosis is thought to be the brain equivalent of wound healing and is typically seen in conditions of neuronal injury, such as stroke and multiple sclerosis,” Thaler said. “We speculate that the early gliosis that we saw may be a protective response that fails over time.”

In their experiments, Thaler said they also detected damage to, and eventual loss of, critical weight-regulating neurons. These neurons, called pro-opiomelanocortin (POMC) neurons, were reduced in number by month 8 of the high-fat diet in mice, according to Thaler. These results were not present in same-age rodents fed standard chow.

It is not yet clear whether this presumed neuronal injury is permanent, but it may contribute to weight gain, he stated.

This research, which was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, provides a new potential target for obesity treatment, Thaler concluded.

“If new medicines can be designed that limit neuron injury during overeating, they may be effective in combating the obesity epidemic,” he said.

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1 thought on “Eating a High-Fat Diet May Rapidly Injure Brain Cells That Control Body Weight”

  1. I’m sorry, ScienceBlog, but I find this post to be very, very disappointing. I understand that the research is yet to be published/released, but considering all the specific details you did go into, I’m quite confused as to why you wouldn’t also include the actual nutrient breakdown of the “typical American diet” these rats were fed vs. the typical rat chow they were being fed prior to the study. You’ve done it with other studies posted here. Why not this one? Diet and nutrition science is confusing and contradictory enough as it is without you holding back on the details that lie at the core of the validity of this research. Considering that the typical American diet is actually high carbohydrate (60+%) and thus highly fattening (but not necessarily high fat) it seems a critical element to include so that we can see if the researchers were correctly controlling/manipulating both the fat and the carbohydrate variables in the generation of their data. Additionally, what specific fats were the rats being fed? Were they being fed coconut oil? olive oil? animal fats? a blend of mufas and pufas? straight trans fats? It definitely matters! Coconut oil is a known anti-inflammatory, so this research would be earth-shattering if it was the oil used in the study, where as trans fats are known to be inflammatory and would give this study a somewhat diminished value in the fight against obesity. Meanwhile high-carbohydrate diets (including the typical American diet) are also known to be inflammatory and this study would lend some insight into a bit to the causation basis of obesity if it turns out that the “typical American diet” that was used was both high fat and high carbohydrate. Considering the group that funded this research and the title that you’ve put on this post, i believe it is irresponsible of you to not include the nutrient breakdown and fat-specific details. Shock value titles and critical detail skipping posts is not what this blog, or people trying to fight obesity with causation-oriented science, needs.

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