Health & Medicine, Australia (Commonwealth Union) – New research in mice has demonstrated that stress has the ability to override natural satiety cues and bring about cravings for sweet foods.
New research conducted by the Garvan Institute of Medical Research and UNSW Sydney has shed light on the negative consequences of combining stress with calorie-dense “comfort” food. While indulging in high-calorie snacks may provide temporary relief, the study conducted on mice suggests that this combination can lead to changes in the brain, ultimately resulting in increased eating, cravings for sweet and highly palatable food, and weight gain.
The study, which appeared in the journal Neuron, revealed that stress interferes with the brain’s natural response to satiety, triggering continuous reward signals that promote the consumption of highly palatable food. The lateral habenula, a specific region of the brain responsible for regulating these reward signals, failed to dampen their effects when activated under stress.
According to Professor Herbert Herzog, the senior author of the study and a Conjoint Professor at UNSW Medicine & Health and Visiting Scientist at the Garvan Institute, the findings indicate that stress can override the brain’s natural mechanism to reduce the pleasure derived from eating. Consequently, the brain remains constantly driven to seek food as a reward.
The research also demonstrated that chronic stress, coupled with a high-calorie diet, amplifies food intake and cultivates a preference for sweet and highly palatable food, ultimately promoting weight gain and obesity. These findings emphasize the importance of maintaining a healthy diet, particularly during times of stress.
Understanding the impact of stress on eating behavior and the brain’s reward system is crucial in developing strategies to combat obesity and promote overall well-being. By recognizing the negative consequences of relying on high-calorie comfort foods during stressful periods, individuals can make more informed dietary choices and seek healthier alternatives to manage stress effectively.
The research highlights the intricate relationship between stress, diet, and brain function. By addressing the unhealthy cycle of stress-driven eating patterns and promoting a balanced diet, individuals can better maintain their overall health and well-being even in challenging times.
In their study, the researchers utilized mouse models to investigate the response of different brain regions to chronic stress under varying dietary conditions. To induce stress, the mice were exposed to a new environment for one-hour multiple times per week. As a result, the mice exhibited increased anxiety-related behavior, and their serum levels of corticosterone, a well-known marker for chronic stress, significantly rose.
The study revealed that the combination of chronic stress and a high-calorie diet produced notable alterations in the brain’s functioning.
Dr. Kenny Chi Kin Ip, the 1st author of the study and a Conjoint Lecturer at UNSW Medicine & Health, as well as a Research Officer at the Garvan Institute, indicated that they observed that a region called the lateral habenula, which is typically involved in suppressing the brain’s reward response, became active in mice on a short-term, high-fat diet as a protective mechanism against excessive eating.
However, when the mice were subjected to chronic stress, this specific brain region remained inactive, allowing the reward signals to persist and promote feeding for pleasure, disregarding signals of satiety regulation. The researchers discovered that the stressed mice consuming a high-fat diet gained twice as much weight as their non-stressed counterparts on the same diet.
These findings highlight the intricate interplay between chronic stress, dietary choices, and brain activity. The activation or deactivation of specific brain regions, such as the lateral habenula, can have a significant impact on eating behavior and weight regulation. Understanding these mechanisms can provide valuable insights into the development of effective strategies to address overeating, weight gain, and the adverse effects of chronic stress on overall health. The researchers indicated that further studies are required to find out how these mouse studies will relate to humans
