There was once a time when the body’s biological clock – the circadian rhythm – was kept in line by our natural environment. We awoke with the breaking of dawn, while the setting of the sun signalled that the day was done and it was time to rest and recuperate. Our daily routine was informed by this 24 hour cycle (give or take a few hours). But today, the increasing invasion of blue-light-emitting devices into our homes may be wreaking havoc on our health by interrupting this cycle. Many of us are guilty of checking our phones relentlessly throughout the evening, or find ourselves still glued to our laptops after the work-day is done. Even the seemingly harmless act of reading an iPad before bed may be doing more damage than we realise.
Blue light, emitted not only by our devices but by energy-saving lightbulbs and the sun, increases productivity and alertness during the day. It does so by inhibiting the production of the hormone, melatonin, by the pineal gland in the brain. Melatonin is the brain’s way of slowing the body down to prepare for sleep. Exposure to blue light during the day can in fact have a positive effect on our sleep patterns in the evenings. However, at night time, with continued exposure to blue light, decreased levels of melatonin ward off drowsiness and impact upon the quality of sleep we have, leaving us unrested and worn out by morning.
This means that as time goes by, we struggle to keep up with the daily demands of work or household chores. Our moods are often affected and in some cases, sufferers of sleep deprivation may experience bouts of depression. A lack of sleep has also been linked to cardiovascular problems, obesity and type 2 diabetes in patients. Recent research has suggested there may even be a correlation between certain cancers and reduced levels of melatonin throughout the evening. As such, feeling a little drained the next day may be the least of our worries if we continue to expose ourselves to excessive blue light after dark.
There are, however, a variety of ways in which we can limit our exposure to blue light at night. As red light has the least power to shift the circadian rhythm and suppress melatonin, dim red lights are preferable as night lights. Doctors also recommend avoiding bright screens at least two hours before bedtime. For those who like to read in bed, a printed book or an original e-reader (such as the first generation Kindle reader) are better alternatives. Blue-blocking glasses are also effective, as are apps that sync up with your particular time-zone and regulate the blue light emissions accordingly, such as F.lux.
With the fast-paced lives we lead, it is often easy to forget how very vital sleep is for us. But, without it, our health and general well-being begin to suffer. So avoid the temptations of technology at night where you can, or safeguard yourself against those blue light emissions as you burn the midnight oil. Your body will surely thank you later.
Date Published: 27 August 2015