Researchers have developed a new generation of blue light-emitting LEDs that could help regulate sleep patterns more effectively. This innovation could both enhance or hinder sleep on command, potentiallu addressing issues caused by the blue light from electronic devices.

A Light for Better Sleep

Blue light from LED lamps and consumer electronics, including your phone, disrupts the production of melatonin, the natural hormone that regulates sleep. Tinted glasses or night mode displays can mask some disruptive wavelengths, but they are not very effective at all. Additionally, a concerning 2022 study found that blue light from smartphones and computer screens may accelerate aging. Now, researchers report in the journal ACS Omega that they’ve designed more “human-centric” LEDs to enhance drowsiness or alertness as needed.

Humans have evolved to be active during the day and rest at night. We rely on the sun to regulate our circadian rhythms. However, many people spend most of their time indoors, away from natural sunlight, making it harder to maintain a healthy 24-hour cycle. Artificial light exacerbates this problem by decreasing melatonin secretion, with blue light from devices like phones and computers being particularly disruptive at night.

To tackle this issue, researchers Changwook Kim, Young Rag Do, and colleagues created LEDs that emit different wavelengths of blue light to support natural circadian rhythms. The researchers call this human-centric LED (HC-LED). They designed two types of LEDs: one for daytime use that restricts blue emissions to wavelengths close to 475 nm, and another for evening use that emits blue wavelengths near 450 nm, which do not disturb sleep.

During the daytime, these LEDs suppress melatonin production, promoting alertness. Conversely, at night, they reduce blue light exposure to encourage melatonin secretion, aiding relaxation and sleep.

Testing the New LEDs

The new LED bulbs were tested in a windowless room equipped with a desk, treadmill, and bed. Individual male volunteers stayed in the room for three days while a computer controlled the type of LED lighting based on the time of day. Researchers compared the effects of conventional bulbs to the new daytime and evening bulbs on melatonin levels.

Saliva samples from 22 volunteers showed promising results. The new LEDs increased nighttime melatonin levels by 12.2% and reduced daytime melatonin by 21.9% compared to consistent exposure to conventional LED T8 bulbs. These findings suggest that the new LEDs could improve nighttime relaxation and sleep quality, as well as daytime alertness and work efficiency.

What’s Next?

Researchers hope that manufacturers of LED lamps and electronic displays will apply these findings to help people achieve better sleep and increased daytime vitality. This development could significantly impact those who struggle with maintaining a healthy circadian rhythm, especially in our modern, indoor-centric lifestyles.

As society continues to grapple with the demands of modern life, innovations like HC-LEDs offer a promising solution to enhance both productivity and quality of life by aligning our indoor environments with our natural biological rhythms.