Chocolate, strawberries, pickles… Pregnant women are known to have specific food cravings. If we don’t know exactly what causes pregnancy cravings, a Spanish study conducted by the University of Barcelona and published in the journal natural metabolism April 4, 2022 advances a path of declaration. According to the researchers, they are linked to changes in neuronal activity.
An attraction for sugary and high-calorie foods
Scientists from the University of Barcelona studied the behavior of pregnant mice. During her pregnancy, the brain undergoes changes, particularly at the level of connections between the cerebral circuits of reward, taste and sensorimotor centers that affect sensory functions and motor skills. They observed that mice, like pregnant women, are more sensitive to sugary foods and develop compulsive behaviors toward high-calorie foods when expecting babies. “Changing these structures prompted us to explore the mesolimbic pathway, one of the signaling pathways of dopaminergic neurons. Dopamine is an important neurotransmitter for motivational behavior“, explains March Claret, researcher and member of the University School of Medicine and the Center for Connected Biomedical Research in Diabetes and Metabolic Diseases. This neurotransmitter is known to affect motivation, productivity, or even focus.
The researchers observed an increase in dopamine levels and an increase in the activity of its receptor, called D2R, in the part of the brain involved in the reward circuit. For researcher Roberta Haddad-Tóvolli, co-director of this study, her work suggests so “Pregnancy Induces a Complete Reorganization of Mesolimbic Neural Circuits Through the Alteration of D2R Neurons”. With his team, they blocked the activity of these receptors to see if behavior changes, and it does: “These neuronal cells – and their modification – would be responsible for the cravings for food, since the fear of food typical during pregnancy disappeared after their activity was blocked“.
What are the consequences of food cravings on the future baby?
If the pregnant woman’s cravings persist, it can have consequences for the unborn child. Because the metabolism and neural circuits that regulate food intake are affected, it can lead to weight gain, anxiety, but also eating disorders (ED). For March Claret, “cThe results are shocking, given that many studies focus on analyzing how the mother’s lifelong habits – such as obesity, malnutrition or chronic stress – affect the baby’s health. However, this study indicates that brief but recurring behaviors such as food cravings are enough to increase offspring’s psychological and metabolic vulnerability. The results of this study could therefore be very useful to improve dietary guidelines for pregnant women.
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