When high-fat and high-calorie foods are consumed regularly, our brain’s ability to regulate hunger cues and calorie intake gets reduced. A new study has shown evidence of how continuously eating a fatty diet seems to disrupt the neurological pathway between the brain and the gut.
The cells in charge of signaling the brain when we’ve had enough food are called astrocytes. According to new research published in The Journal of Physiology, calorie intake is regulated in the short term by astrocytes (large star-shaped cells in the brain that regulate many different functions of neurons in the brain). Astrocytes also control the signaling pathway between the brain and the gut, a path that can get interrupted by high-calorie diets.
This study provides great insight into the brain’s role in weight gain and obesity and also how intuitive eating might not be the best road for everyone. The complex mechanisms that lead to overeating could have a neurological explanation, after all, and knowing this could help experts develop therapies to treat overeating.
Dr. Kirsteen Browning, Penn State College of Medicine, said, “Calorie intake seems to be regulated in the short term by astrocytes. We found that a brief exposure (three to five days) to a high-fat/calorie diet has the greatest effect on astrocytes, triggering the normal signaling pathway to control the stomach.
“Over time, astrocytes seem to desensitize to high-fat food. Around 10–14 days of eating a high-fat/calorie diet, astrocytes seem to fail to react, and the brain’s ability to regulate calorie intake seems to be lost. This disrupts the signaling to the stomach and delays how it empties.”
Astrocytes initially react when high-fat/calorie food is ingested. Their activation triggers the release of gliotransmitters, chemicals (including glutamate and ATP) that excite nerve cells and enable normal signaling pathways to stimulate neurons that control how the stomach works. This ensures the stomach contracts correctly to fill and empty in response to food passing through the digestive system.
However, when astrocytes are inhibited, this mechanism is disrupted. The decrease in signaling chemicals leads to a delay in digestion because the stomach doesn’t fill and empty appropriately.
This would prove that consistent intake of fast and fatty foods, which we already know leads to obesity, also has a long-term neurological effect, damaging our brain cells and making weight loss more difficult. Obesity is a public health concern worldwide, as it is associated with a higher risk of cardiovascular diseases and type 2 diabetes. In The United States, 69% of adults are overweight, and 36% of these are living with obesity. One out of six children is obese, and one out of three children is at least overweight.
