Researchers at the Justus Liebig University in Giessen (Germany) are investigating the brain’s influence in the desire for high-calorie sweet and savory foods just before menstruation.
Many women experience a sudden craving for sweets or salty foods shortly before the start of their period, in addition to mood swings, or concentration problems among other symptoms. These premenstrual symptoms and cravings for certain foods are mainly associated with the biochemical changes during the menstrual cycle. A research team from the Justus Liebig University Giessen (German acronym: JLU) has now investigated in more detail whether the female brain is particularly sensitive to food stimuli shortly before menstruation.
The teams within the university chairs for Psychotherapy & Systems Neuroscience and Differential & Biological Psychology at JLU repeatedly invited 35 young healthy women who are not using hormonal contraception to the laboratory over a period of three months - in the first half of the cycle, at ovulation and in the period shortly before menstruation. The women were asked to look at pictures of high and low-calorie foods and to evaluate them in terms of their palatability.
To measure attention and sensitivity to the images, the scientists used an electroencephalogram (EEG) to derive the brain waves of the women and measured the respective concentration of the sex hormone progesterone. Based on their own experience, the women also provided information on complaints and impairments in connection with the monthly cycle. Some of them reported feeling unwell or in pain, but also impairments in their social relationships, for example in their work environment or hobby activities.
The data collected in the study show that women react much more sensitively to images of high-calorie foods in the period shortly before menstruation than in other phases of the cycle. However, this effect was not observed for low-calorie images. The main study author Dr. Jana Strahler summarizes the results: "The lower the progesterone concentration and the greater the impairments that the women reported in connection with their periods, the lower was the EEG response to images of high-calorie foods. There were no differences in the subjective evaluation of the images.
The research team, therefore, assumes that women with low premenstrual progesterone levels and higher premenstrual symptoms find it easier to focus their attention on food stimuli. Whether such a changed response is also relevant for the development of eating disorders, obesity or premenstrual dysphoric disorders is still unclear.
Further studies in patients will be helpful in showing whether a reduced sensitivity to high-calorie foods makes them susceptible to excessive consumption of highly sweet and high-fat foods or - on the contrary - even protects them from it.
Strahler, J., Hermann, A., Schmidt, N. M., Stark, R., Hennig, J., & Munk, A. J.: Food Cue-Elicited Brain Potentials Change Throughout Menstrual Cycle: Modulation by Eating Styles, Negative Affect, and Premenstrual Complaints. Hormones and behavior DOI: 10.1016/j.yhbeh.2020.104811