Student investigates the relationship between night light and food intake

Bratislava, 8 December 2022: People who are exposed to soft ambient light at night are more likely to gain weight and have diabetes. This negative effect on metabolism could, however, be reversed by timing meals correctly during the day. Valentína Rumanová, a PhD student at Comenius University Bratislava, received a grant from the university to study the impact of night light smog on digestion.

12. 12. 2022 16.49 hod.
By: CU External Relations Office

Night lighting affects the functioning of the central circadian clock, causing changes to hormonal rhythms, food and water intake, as well as metabolism. Even very low intensity ambient light produced by street lamps or advertising signs which surround us in cities, represents a risk.

Valentína Rumanová from the Faculty of Natural Sciences studies the mechanisms through which changes occur in the organism. She and her team carry out research on rats, whose metabolism is similar to that of humans. They discovered that even subdued ambient light at night disrupts the body's circadian rhythms, affecting both behaviour and molecular processes. The consequence is the disruption of internal rhythms, which could contribute to the emergence and more rapid progress of diseases.

"During my study visit at the Medical Center of the University of Amsterdam, and while working in Professor Kalsbeek’s lab, I conduced an experiment in which we discovered that the disruptive effect of dim night lighting can, to some extent, be mitigated by limiting food intake to the active phase," Valentína Rumanová from CU explains how the research originated.

Soft ambient lighting at night stimulates increased storage of fat in the liver, which is not adapted to long-term fat storage, causing a negative effect on various metabolic pathways. However, little is known about the consequent changes to the circadian rhythms of rats, mice, or humans.

If the relationship between the time of food intake and ambient night lighting is confirmed, new therapies could be designed for people with metabolic diseases, obesity or diabetes. Eating at correct times could slow down the course of their disease or even suppress it.