Sitting by a window may improve blood sugar levels for type 2 diabetes

Many of us sit near a window to lift our mood, but exposure to natural light during the day also appears to improve blood sugar control in people with type 2. diabetes.

Our cells and tissues follow circadian rhythms, 24-hour cycles of metabolic activity that regulate things like blood sugar levels. Research has shown that exposure to artificial light at night disrupts these rhythms. increased blood sugar levelsalthough spending more time outside in the sunshine seems increase the body's response to insulina hormone that helps control these levels.

But none of these studies examined the potential benefits of exposure to natural light through a window, even though most people spend most of their time indoors, he says. Joris Hoeks at Maastricht University in the Netherlands.

To find out more, Hooks and his colleagues recruited 13 people with type 2 diabetes, average age 70, who spent 4.5 days in a room where they were exposed exclusively to natural light through large windows from 8 a.m. to 5 p.m.

Participants who continued to take their regular diabetes medications mostly sat at a table where they had access to their phones and computers, with screens set to low brightness levels. In the evenings, they were exposed to dim artificial light and had access to their devices until 11:00 pm, and then slept in complete darkness until 7:00 am. They all ate the same three times a day, not to gain or lose weight, and did the same exercises at specific times for 4.5 days.

The researchers also conducted a very similar experiment with the same participants, but this time they sat in rooms with no windows and only artificial lighting. This was done either one month before or one month after the natural light portion of the study.

During both experiments, participants wore devices that continuously monitored their blood sugar levels, although technical problems meant this data was only available for 10 of them.

It showed that during a week of natural light, participants' blood sugar levels remained within a healthy range 50 percent of the time. In the artificial light experiment, this range was reached only 43 percent of the time.

Definitions of a healthy blood sugar range vary. The researchers determined it to be between 4.4 and 7.2 millimoles per liter, which is more or less what UK National Health Service And US Centers for Disease Control and Prevention say.

Although the differences in data between the two experiments may seem relatively small, spending a lot of time outside the healthy range can affect someone's outcome. risk of diabetes complications“For example, heart problems,” Hooks says.

As for why exposure to sunlight might have this effect, light-sensitive cells in the eye play a central role in regulating metabolic activity cycles and are more sensitive to the shorter wavelengths of natural light, Hooks says.

More research is needed to establish this, he said, but for now, many people with type 2 diabetes may benefit from getting more natural light, even if it means just sitting near a window. “It's simple, it's free, and it's accessible to everyone,” Hooks says. It is unclear whether people with type 1 diabetes or prediabetes (when someone's blood sugar levels are higher than normal but not high enough to be diagnosed with type 2 diabetes) will receive the same benefit.

Glen Jeffrey University College London says larger studies are needed to confirm the results. However, he adds that “the importance of daylight is only gradually being realized.”