A study published in the journal of the European Association for the Study of Diabetes (Diabetologia) will support better management of outdoor artificial light at night (LAN) and actions such as using black-out curtains in bedrooms. Yu and colleagues determined that LAN “is associated with impaired blood glucose control and an increased risk of diabetes. . . .
Grant and colleagues investigated falls in care homes by elderly (mean age 81 +/- 12 years old) residents. They report that some test locations “had solid-state lighting installed throughout the facility that changed in intensity and spectrum to increase short-wavelength (blue light) exposure during the day (6 am–6 pm) and decrease it overnight (6 pm–6 am). The control sites retained standard lighting with no change in intensity or spectrum throughout the day. The number of falls aggregated from medical records were assessed over an approximately 24-month interval. . .
Circadian lighting for better lives
New research confirms the value of circadian and natural lighting. Teruel and colleagues determined that “Disruption of the circadian clocks that keep the body and its cells entrained to the 24-hour day-night cycle plays a critical role in weight gain. . . factors that throw the body’s ‘clocks’ out of rhythm may contribute to weight gain.”
Best ways to use LEDs
Benedetti and colleagues learned that the lighting of places where people are working influences how well they sleep at night. The team reports that they “tested the effects of optimized dynamic daylight and electric lighting on circadian phase of melatonin, cortisol and skin temperatures in office workers. We equipped one office room with an automated controller for blinds and electric lighting, optimized for dynamic lighting (= Test room), and a second room without any automated control (= Reference room).
Jiang and teammates studied humans’ responses to multicolor light in the context of space travel, but their findings are likely to be relevant in other situations. The group shares that “The goal of this study . . . was to test whether multicolour lighting can improve people’s psychological state in an isolated and confined environment over a period of seven days. . . . [participants] were randomly divided into two groups: one group that was exposed to multicolour lighting and a control group, which was exposed to a static, monotonous white interior. . . .
Circadian lighting helps us feel tip top, keep our stress levels in check, and do whatever mental gymnastics are required of us to our full potential. Neuroscience research is packed with insights into how to “circadian light.”
The Mason team’s findings support calls to keep light levels low in spaces where people are sleeping. The group reports that their “laboratory study shows that, in healthy adults, one night of moderate (100 lx) light exposure during sleep increases nighttime heart rate, decreases heart rate variability (higher sympathovagal balance), and increases next-morning insulin resistance when compared to sleep in a dimly lit (<3 lx) environment.