Embrace the dark(er) side
The shortest day of the year is approaching and here in the UK, it is getting dark around 4 pm again. Many people struggle with the lack of daylight in winter and experience Seasonal Affective Disorder (SAD). One of the causes of their disorder is the confused melatonin levels in their body. In 2002, David Berson and his colleagues found a special type of cell in the retina of our eyes that does not contribute to our vision. Instead, these cells act like a light switch. If they register blue light, they send a signal to the pineal gland to stop producing melatonin and crank up the body’s metabolism.
This signal is the reason why we are not supposed to sit in front of our phones, TVs or computers in the evening before we go to bed. The blue-ish light from LEDs literally keeps our bodies switched on.
On the other hand, if you want to wake up in the morning, then blue light is good for you because it helps your body wake up faster. Ideally, you would wake up with the morning sunlight, or take a walk in the morning to help you get started, but during this time of year that would probably condemn you to start working sometime around 10 am (well, some people do that anyway, so they are fine).
Unfortunately, in our society, we are constantly exposed to artificial light and in particular to the cold light of LEDs and other forms of artificial lighting. And apparently, this environment alone causes our bodies to go into permanent overdrive and in the long run, can have terrible health consequences. In 2012, the American Medical Association adopted a policy statement that concluded that, once all other influences had been controlled for, the exposure to artificial light caused depression, obesity, reproductive problems, and cancer. In fact, the clearest evidence of the poor influence of artificial light has been found with breast cancer in women. Blind women have a significantly lower rate of breast cancer because their light receptors that regulate melatonin production in their body do not work. Hence, these women have a naturally regulated body clock and circadian rhythm and a significantly lower rate of breast cancer.
What do we learn from this: Light hygiene is crucial, particularly in the darker time of the year. By all means, use blue light and artificial light in the morning and throughout the day. But make sure you do two things: First, try to get proper sunlight during the day (e.g. go for a walk over lunch). This will regulate your circadian rhythm and helps reduce the impact of SAD. Second, once it gets dark in the afternoon, go with the flow and embrace the darkness. Your body needs to wind down and get some rest.
I suggest an experiment. Once it is past 6 pm, try to avoid watching TV or sitting in front of your computer or phone altogether. Instead, listen to music or the radio or read. But do it with an old-fashioned incandescent light bulb, not with energy-saving LEDs. I guess you will pretty quickly find out that not watching TV or your phone will reduce stress dramatically and relax you. And in the long run, you reduce your risk of high blood pressure, heart disease, cancer, and diabetes. The dark side comes with many benefits, so let’s embrace it.