THE ESSENTIAL
- Researchers have studied the link between increased dopamine levels and food cravings in pregnant women
- These cravings can cause eating disorders in the mother and impact the health of the baby.
- This study could help improve nutritional guidelines for pregnant women to ensure good prenatal nutrition and prevent disease development
Want strawberries, chocolate… the cravings of pregnant women are the subject of many myths and popular beliefs. During this period, the mother’s body undergoes a series of physiological and behavioral changes in order to create a favorable environment for the development of the embryo, and food cravings are said to be one of the symptoms. We do not yet really know the hormonal mechanisms that cause them, but a study published in the journal Nature Metabolism provides new evidence on the alterations in neural activity that cause food cravings.
More sensitive to sugary foods
To conduct their study, researchers from the University of Barcelona studied the behavior of female mice. During pregnancy, their brain undergoes changes in the functional connections of brain reward circuits, as well as taste and sensorimotor centers. Like pregnant women, female mice are more sensitive to sugary foods, and they develop compulsive behaviors towards high-calorie foods. “The alteration of these structures made us explore the mesolimbic pathway, one of the signal transmission pathways of dopaminergic neurons. Dopamine is a key neurotransmitter in motivational behaviors“, notes March Claret, member of the Department of Medicine at UB and the Center for Networked Biomedical Research in Diabetes and Associated Metabolic Diseases (CIBERDEM).
Increase in dopamine levels
The team observed an increase in dopamine levels – and the activity of its receptor, D2R – in the nucleus accumbens, a region of the brain involved in the reward circuitry. “This finding suggests that pregnancy induces a complete reorganization of mesolimbic neural circuits through D2R neurons,” notes researcher Roberta Haddad-Tóvolli who is leading the study with March Claret. “These neuronal cells – and their alteration – would be responsible for food cravings, since food anxiety, typical during pregnancy, disappeared after blocking their activity.“
Effect on children
Researchers have also found that persistent food cravings have health consequences for future children. They affect metabolism and the development of neural circuits that regulate food intake, leading to weight gain, anxiety and eating disorders. “These findings are shocking, as many studies focus on analyzing how lifelong habits of the mother — such as obesity, malnutrition or chronic stress — affect the baby’s health. However, this study indicates that brief but recurrent behaviors, such as food cravings, are sufficient to increase the psychological and metabolic vulnerability of the offspring.“, concludes March Claret.