Why Researchers Say Natural Light Is Important For Diabetes Prevention & Management

From mindbodygreen.com 

Over 37 million adults in the U.S. are living with diabetes, and that number is only expected to grow, making preventive approaches to managing blood sugar paramount for all of us.

Beyond the food we eat, what else can be done to prevent diabetes? And if you already have it, how can you better manage it? According to research presented at the European Association for the Study of Diabetes, natural light could play a role—here's what to know.

                                                                              Image by Alexey Kuzma / Stocksy

The connection between circadian rhythm and metabolic function

For this study, researchers wanted to look at the connection between natural light, the circadian rhythm, and metabolic function. To do so, they conducted a small study of older participants with Type 2 diabetes (average age was 70 years old), in which participants stayed in a research facility where light exposure, meals, and activity patterns were controlled.

For part of the study, they were exposed to artificial LED lighting, and in the other, natural daylight. In both lighting settings, the researchers looked at things like blood sugar levels, insulin production, body temperature, respiratory exchange ratio (which reveals whether fat or carbs are being used for energy), and more.

And based on the findings, it would appear that natural light reigns supreme when it comes to preventing diabetes. Namely, blood glucose levels were within the normal range for longer on days spent with natural light, compared to artificial lighting. Further, natural light saw a lower respiratory exchange rate in participants, meaning it was easier for the participants to burn carbs and fat for energy.

Of course, considering natural light is one of the best things you can get to regulate your circadian rhythm, the authors also note that the genes that control circadian rhythm were more active in natural light conditions than artificial ones.

The respiratory exchange ratio was lower during the daylight intervention than during the artificial light intervention, indicating that the participants found it easier to switch from using carbohydrate to fat as an energy source when exposed to natural light.

What to do about it

According to study co-author and Ph.D. candidate Ivo Habets, these findings suggest that exposure to natural light is not only beneficial to your metabolic health but could even help with the treatment and prevention of Type 2 diabetes and other metabolic conditions.

"The type of light you are exposed to matters for your metabolism. If you work in an office in almost no exposure to natural light, it will have an impact on your metabolism and your risk or control of Type 2 diabetes," Habets explains in a news release, adding, "So try to get as much daylight as possible, and ideally, get outdoors when you can."

The takeaway

While the researchers note that more research is needed to figure out just how much natural light we need to compensate for all the time spent in artificial lighting, opening up the blinds—or better, getting outside—is a pretty simple ask.

Not only can it help keep your circadian rhythm regulated, but according to this research, it could just help prevent and manage Type 2 diabetes.

https://www.mindbodygreen.com/articles/natural-light-may-help-control-blood-sugar-new-research-suggests

How daylight may help people with type 2 diabetes regain metabolic balance

From thehansindia.com

A growing body of research is reshaping the way we understand health, and the latest findings suggest that something as simple and accessible as daylight could play a meaningful role in managing type 2 diabetes. A new study indicates that exposure to natural light can improve metabolic health and help people with the condition achieve better blood sugar control, highlighting the powerful link between light, the body’s internal clock, and metabolism.

Conducted by researchers from the University of Geneva (UNIGE) in Switzerland and Maastricht University in the Netherlands, the study offers the first direct evidence that natural daylight has measurable benefits for people living with type 2 diabetes. The findings were published in the scientific journal Cell Metabolism. 

Daylight and blood sugar control

The study revealed that individuals exposed to natural light spent more hours each day with blood glucose levels within the normal range. Not only were their glucose levels better regulated, but they also showed less variability — a key factor in managing diabetes and preventing long-term complications. Compared to artificial lighting, daylight appeared to provide a more stable metabolic environment, helping the body process glucose more efficiently. This suggests that beyond diet and medication, environmental factors like light exposure may significantly influence glycaemic control. 

The role of the body clock 

For years, scientists have known that the disruption of circadian rhythms — the body’s internal 24-hour clock — is closely linked to metabolic disorders. Charna Dibner, associate professor at UNIGE and one of the study’s authors, explained that circadian misalignment plays a major role in the rising prevalence of metabolic diseases, particularly in Western societies.

Natural light acts as the strongest regulator of the circadian rhythm. By aligning the body’s internal clock more accurately with the day-night cycle, daylight helps coordinate metabolic processes, including insulin sensitivity and glucose metabolism. “This coordination between the central clock in the brain and the clocks in peripheral organs may be key to improved blood sugar regulation,” Dibner noted. 

Inside the study 

To explore this relationship in detail, the research team recruited 13 volunteers aged 65 and above, all diagnosed with type 2 diabetes. Each participant spent 4.5 days in specially designed living environments. One setting was illuminated primarily by natural daylight entering through large windows, while the other relied on artificial lighting. After a washout period of at least four weeks, the volunteers returned for a second session, switching light environments. This crossover design allowed researchers to directly compare how the same individuals responded to different lighting conditions.

What the scientists measured 

To understand the biological mechanisms behind the changes, the researchers collected blood and muscle samples before, during, and after each lighting exposure. They examined molecular clocks in skeletal muscle cells, along with lipids, metabolites, and gene transcripts in the blood. The analysis showed that natural light positively influenced the regulation of these molecular clocks, which play a crucial role in metabolic function. The results also pointed to improved fat oxidative metabolism, meaning the body was better able to burn fat for energy.

Beyond blood sugar: Sleep and hormones 

Another notable finding was the impact of daylight on melatonin, the hormone responsible for regulating sleep. Participants exposed to natural light had slightly higher melatonin levels in the evening, suggesting improved sleep signalling.

Better sleep quality and timing are closely linked to metabolic health, reinforcing the idea that daylight supports the body in multiple, interconnected ways. 

A simple, promising intervention 

Taken together, the findings strongly indicate that natural light influences both metabolism and the internal clock. This could explain the improved blood sugar regulation and metabolic coordination observed in the study. 

While larger studies are needed to confirm these results, the research opens the door to new, non-invasive strategies for managing type 2 diabetes. Something as straightforward as increasing daily exposure to daylight — at home, work, or during outdoor activity — may one day become a valuable complement to existing treatments.

In an era of artificial lighting and indoor lifestyles, the study serves as a reminder that aligning with nature’s rhythms could be a powerful tool for better health.

https://www.thehansindia.com/featured/sunday-hans/how-daylight-may-help-people-with-type-2-diabetes-regain-metabolic-balance-1038474#
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