A new sleep study in Berlin has found that exposure to just ten minutes of bright light just before bedtime, for instance in bathroom or from a computer screen, can be enough to slow the body’s melatonin levels and result in poor quality sleep.
The research at Charite University Hospital showed that those who experience light environments in the run up to sleep suffer from disrupted circadian rhythm, and therefore don’t achieve the same levels of sleep compared to people who spend the evening in low light conditions.
Melatonin is the ‘sleep’ hormone naturally produced in the evening, and is vital for the sleep/wake cycle. Light is one of the main environmental factors that determines the release of the hormone, and, as the Berlin study among others shows, artificial light has just as much effect as natural light.
“The blue light more or less tells the body, ‘It’s daytime, be alert’,” commented team leader Dieter Kunz.