New paper shows that oxytocin modulates how our brain responds to food pictures.
Often referred to as the "love hormone", oxytocin is a small neuropeptide made in the hypothalamus of our brains and released by the pituitary that is important for social bonding, feelings of empathy, and during childbirth and breastfeeding. We became interested in this hormone following recent studies in animals showing that oxytocin may also have effects on appetite and body weight. In our study, we wanted to know whether oxytocin affects appetite and whether the human brain response to food cues changes after administration of oxytocin.
Many thanks to the 24 healthy volunteers who completed this study. Each participant was studied on four occasions: during two visits we did a special brain scan, called a functional Magnetic Resonance Imaging (fMRI) scan and during the other two visits we provided a special test meal - sometimes people received oxytocin via a nasal spray, sometimes they received placebo (saline) - this was blinded to both the participants and the researchers.
Our results showed that oxytocin didn't have an effect on reducing food intake. However, the fMRI part of the study did show some interesting results. An fMRI scan can help us look at how the brain responds to pictures of appetising foods for instance, such as a delicious piece of chocolate cake, ice cream etc. We would expect to see certain areas of the brain becoming more active and actually "lighting up" in the scanner when people see such pictures. But, we found that oxytocin actually reduced this "lighting up" in the brain area known as the hypothalamus. This is particularly interesting as the hypothalamus is a key area in the brain controlling our weight. We now need to do further studies to investigate whether this hormone can ultimately be used in the treatment of obesity.