Link Examined Between High-Fat Diet and Depression

There is widespread national concern about the obesity epidemic. In schools children are taught about healthy eating and exercise habits and in some families the practice of cooking with only natural, organic ingredients becomes almost a religion. Obesity can affect many other areas of health. The risk of heart disease, cancer, and diabetes are all increased by obesity, and many mental illnesses are affected and sometimes worsened by obesity. A new study by researchers at University Hospital Research Centre in Montreal and members of the university’s Faculty of Medicine explore the connection between obesity and depression. The study uses advanced neuro-science to explore the changes in the brain that come with depression and obesity. In a recent issue of the International Journal of Obesity, authors Sandeep Sharma and Stephanie Fulton published a study that examined the link between depressive behaviors and adaptations in the brain reward circuitry that resulted from obesity. The study shows how the relationship between depressive symptoms and high-fat diets might be explained. Dr. Fulton says that while high-fat foods cause obesity, they also mimic illegal drugs in their alteration of chemicals in the brain, with depression being one result of eating rich foods. The alteration initiates a cycle of “food highs” being used as a self-treatment for depression, with the resulting low initiating another intake of high-fat foods. Dr. Fulton also explains that while research has shown that obesity has a definite link with an increased risk of developing depression, there has been little research providing information about the neural mechanisms and reward patterns in the brain that connect depression and obesity. This is the first study, says Dr. Fulton, to show the progression of chronic high-fat food consumption leading to pro-depressive results. The researchers were interested in understanding how dopamine was affected by obesity. Dopamine is located in the brain and controls the reward and pleasure experience, with an important role in not only experiencing the reward but also the motivation to seek out the reward and pleasure again. It is heavily involved in encouraging individuals to seek out certain kids of behaviors to experience pleasure. In the study, the researchers gave different types of food to mice and monitored the resulting behaviors exhibited by the animals. The animals that were given a high-fat diet exhibited signs of anxiety in open spaces, in addition to symptoms of depression. The mice given a high-fat diet were less likely to attempt escape when they were trapped. The researchers also noted that the high-fat diet also physically altered the animals’ brains. There was increased activation in certain areas, specifically those dedicated to memory function and stress levels. The information gained by this research will aid in understanding the full impact of obesity on the overall health of the patient.