Weight Loss with Light? A New Study Explores the Pathway

SadaNews - A recent scientific study has revealed that exposure to bright light does not only affect sleep and mood but may also play a direct role in reducing appetite and limiting weight gain, at least in animal experiments, opening the door to new approaches in combating obesity, according to a report published on the "MedicalXpress" practical website.

The study, published in the journal Nature Neuroscience, was conducted by researchers from Jinan University and several research institutions in China, focusing on understanding how bright light affects eating behavior and weight through specific neural pathways in the brain.

The researchers relied on an adult mouse model, dividing the animals into groups that were exposed to different levels of light during the daytime, ranging from very dim lighting to bright light of up to 5000 lux, an intensity comparable to strong indoor lighting.

The results showed that mice exposed to bright light consumed less food compared to the other groups, and recorded less weight gain during the experiment, without significant changes in activity levels.

Importantly, the study not only identified behavioral outcomes but also pinpointed the neural pathway responsible for this effect. Researchers managed to trace a neural circuit that starts from specialized cells in the retina, with signals transmitted - via a specific pathway - to an area of the brain known for its role in regulating appetite and eating behavior.

Researchers clarified that activating this visual-neural pathway inhibits the neurons associated with food intake, explaining the noticeable decrease in food consumption and weight gain.

Bright light therapy is already used to treat certain psychological disorders, such as seasonal depression and sleep disorders, relying on exposure to strong artificial light for a specified duration each day. This study suggests that the benefits of this type of therapy may extend to include weight regulation and metabolism.

The researchers believe that the results provide a clear biological explanation for previous observations linking exposure to bright light with weight loss, although the underlying neural mechanism had not been thoroughly understood.

Future Prospects

Although the study was conducted on mice, the researchers assert that the results pave the way for future research to investigate whether the same mechanism operates in humans. If proven, light therapy could become part of new non-pharmacological strategies for preventing obesity or supporting weight loss.

The researchers conclude by emphasizing that light, as a daily environmental factor, may have a greater impact on our metabolic health than we previously thought, not only through the biological clock but also via neural circuits that directly control appetite and food consumption.