Daylight exposure can enhance metabolic health in individuals with type 2 diabetes, leading to better glycaemic control, as per a study conducted by researchers from the University of Geneva (UNIGE) in Switzerland and Maastricht University in the Netherlands. The study revealed that individuals exposed to natural light maintained blood glucose levels within the normal range for more extended periods each day, with reduced variability. Additionally, their melatonin levels were slightly higher in the evening, and fat oxidative metabolism showed improvement.
The research, published in the journal Cell Metabolism, marks the first evidence of the positive effects of natural light on individuals with type 2 diabetes. According to Charna Dibner, an associate professor at UNIGE, disruptions in circadian rhythms have been linked to the development of metabolic disorders affecting a growing segment of the Western population.
In the study, 13 volunteers aged 65 and above, all diagnosed with type 2 diabetes, were recruited. They spent 4.5 days in specially designed living spaces illuminated either by natural light through large windows or artificial light. Following a minimum four-week break, they participated in a second session under the alternate lighting conditions.
To comprehend the observed metabolic improvements, researchers collected blood and muscle samples from the volunteers before, during, and after each light exposure. Analysis of molecular clock regulation in cultured skeletal muscle cells, along with lipids, metabolites, and gene transcripts in the blood, was conducted.
The findings indicate a clear influence of natural light on the body’s internal clock and metabolism. Dibner suggested that this influence might explain the enhanced blood sugar regulation and improved coordination between the central brain clock and organ clocks.
