Daylight helps people with diabetes
The modern lifestyle is increasingly taking place indoors. In industrialized countries, people spend up to nine-tenths of their time indoors under artificial light, which is much less bright and dynamic than solar light. This is important because the body’s work is subject to circadian rhythms — the internal circadian clock that regulates metabolism, body temperature, and food intake. Light serves as the main guideline for these rhythms, and its lack has long been considered as a risk factor for metabolic disorders. A new study shows that a few hours spent next to a window in natural light can significantly improve blood glucose control. The work was published in the journal Cell Metabolism and attracts attention by the fact that it is not about drugs or complex interventions, but about the environment familiar to most people.
The team of scientists decided to test whether daylight entering the room through the window affects the condition of people with diabetes. Thirteen volunteers with a confirmed diagnosis participated in the experiment. Each of them spent two separate periods of four and a half days in an office space with tightly controlled conditions. In one case, the participants worked at tables near large windows from morning until late afternoon, in the other, they were in the same room, but with the windows fully closed and standard office lighting. Nutrition, physical activity, and taking prescribed medications remained the same.
The average blood glucose values in both regimens were almost the same. The noticeable difference was shown in another way. In natural light, participants spent more time within normal sugar levels, without sudden spikes. The metabolism also changed: the body used fats more actively as an energy source and relied less on carbohydrates.
Additional data was provided by studies of muscle tissue. The analysis showed that in daylight, the genes associated with the cellular biological clock worked more consistently with the real time of day. Simply put, sunlight helped the muscles stay in rhythm, making them more efficient at processing nutrients.
The results point to a simple and affordable way to reduce sugar fluctuations throughout the day. For people with type 2 diabetes, this can be an additional support to existing therapy — without changing medications and diet, but with a review of where and under what lighting the working day takes place.
Published
December, 2025
Category
Medicine
Duration of reading
2-3 minutes
Share
Source
Scientific Journal Cell Metabolism. Article: «Natural daylight during office hours improves glucose control and whole-body substrate metabolism»
Don’t miss the most important science and health updates!
Subscribe to our newsletter and get the most important news straight to your inbox
