Obese people who eat huge amounts of food may be doing so because regions of their brain that control satiety (fullness) are also those that trigger cravings for drug addicts, say researchers from New York, USA. The scientists say that they now have a better understanding of how the brain and the stomach interact with emotions to cause overeating and obesity.
You can read about this study in Proceedings of the National Academy of Sciences.
The scientists scanned the brains of seven obese people, all of whom had had an implantable gastric stimulator (IGS) fitted for one to two years. An IGS is a device that sends signals to the vagus nerve, which sends the message on to the brain telling it that the person is full. The device has been shown to reduce the desire to eat.
Each volunteer underwent two positron emission tomography (PET) brain scans two weeks apart. One when the IGS was switched on and another when it was switched off. The volunteers were not told when the devices were switched on or off. Before the scans, they were injected with a a radioactively labeled form of glucose – so that the scanner could track brain metabolism.
The scans showed higher activity in the hippocampus. The hippocampus is an area of the brain linked to emotions, memory, learning and processing of sensory and motor impulses. The hippocampus has an important role in retaining memories related to prior drug experiences in drug addicts – it is likely that the memories of fullness in these obese volunteers might also be stimulated by hippocampal activation, say the scientists.
In other words, the scientists saw a similarity in these people’s brain activity and that of drug addicts when they are craving for their drug. Identical parts of the brain became active in similar ways. This indicates, say the researchers, that is going on in the brain of an obese person who wants to eat is virtually identical to what goes on in a drug addict’s brain when he/she wants his/her fix.
The researchers believe these brain circuits play a critical role in behaviors linked to calming negative emotions.
Lead author, Gene-Jack Wang, Brookhaven Lab’s Center for Translational Neuroimaging, said ?This study opens new territory in understanding how the body and brain connect to each other, and how this connection is tied to obesity. We were able to simulate the process that takes place when the stomach is full, and for the first time we could see the pathway from the stomach to the brain that turns ?off’ the brain’s desire to continue eating.?
Click here to see the article in the Brookhaven National Laboratory’s web site
Written by: Christian Nordqvist
Editor: Medical News today