Swiss Science Discovers That Sunlight Cures Diabetes 0 9

Metabolic diseases are reaching epidemic proportions. A significant role in this is played by a sedentary lifestyle and disruptions in circadian rhythms – the desynchronization between internal biological clocks and environmental signals. People spend up to 90% of their time indoors and receive very little natural light.

To determine how exactly daylight affects metabolism and blood sugar control, researchers from the University of Geneva and partner centers conducted a controlled study involving 13 individuals with type 2 diabetes. Under the influence of natural lighting, participants showed more stable glucose levels and improved metabolic indicators. The work, published in Cell Metabolism, is the first direct confirmation of the benefits of daylight for individuals with type 2 diabetes.

The study included 13 volunteers over the age of 65 with type 2 diabetes. Each spent 4.5 days in specially equipped rooms: either with natural light from large windows or under artificial lighting. After at least four weeks, participants returned for a second session – but in a different lighting condition.

Even in such a short period, the impact of light was noticeable: individuals exposed to daylight had their sugar levels remain normal for longer and fluctuate less. To understand what exactly happens in the body, scientists took blood and muscle tissue samples before, during, and after each period. They studied the functioning of "molecular clocks" in muscle cells, as well as analyzed lipids, metabolites, and gene activity in the blood. The combined data showed that natural light affects internal clocks and metabolism, which may improve blood sugar control and synchronize the functioning of central and peripheral biological clocks.

The study was conducted on a small group of elderly individuals with type 2 diabetes and lasted for a short time. Despite this, the data obtained became the first confirmation that natural daylight positively affects metabolic health compared to artificial lighting, under which we typically spend most of our lives.