0308 GMT November 21, 2019
Yet when it comes to light, so many of us are on a junk diet, says Karl Ryberg, an architect and psychologist who studies photobiology, the effect of colors and light on humans and animals, according to telegraph.co.uk.
Ryberg said whether it’s natural, daylight, moonlight, a red fire or blue screen glow, all light has an impact on our well-being.
He hailed from Sweden, where there are marked light extremes between long summer days and dark winter nights, and where the impact of light on mood has been obvious to those who have lived there for generations.
It wasn’t until the Eighties that seasonal affective disorder (SAD) was medically proven and the rest of the world started to catch up. Yet Ryberg feels that too many of us are still in the dark on the subject.
To rectify this, he has written a book titled ‘Light Your Life’ to help people use light to boost their brain function, their mood, sleeppattern and overall well-being.
“My idea was to write a cookbook on how to feed your brain,” he explained.
“Light for the brain is like food for the tummy. The brain eats light and the tummy eats chemicals, which we call food. So many people are completely ignorant; they make any kind of light salad and they end up with insomnia, migraines or vitamin D deficiency as a result.”
For Ryberg, the basis of a healthy light diet is a pyramid consisting of natural sunlight, a bit of moonlight and seeing the stars now and then. “That’s been feeding our biology for the last five million years. Our DNA is naturally coded to natural light and we don’t get enough of it.”
In the modern world we spend 90 percent of our time indoors. Ryberg did not suggest we go back to hunting and living in caves, but rather that we make the best of a bad situation.
Some artificial light sources are obviously worse than others; disco-style strobe lights can give people epileptic seizures, for instance. But even a computer screen will flicker imperceptibly. “If you shift your gaze quickly, the light is not stable. The brain is used to sunlight, which never flickers or pulsates,” said Ryberg.
He explained that staring at a flickering computer screen will over-activate your brain, triggering hyperactivity and leaving you exhausted. “It’s like drinking Fanta that tastes like orange, but it is not,” he said.
The same goes for blue screen light from mobile phones, fluorescent tubes and even energy saving lamps. “Electric light is like canned food. It feeds your body but it doesn’t give you energy,” said Ryberg.
As winter nights grow longer, those who suffer from seasonal affective disorder may opt to use a special SAD lamp, to help trigger the release of the hormone serotonin, but Ryberg warned that many use fluorescent tubes.
Instead, the best thing is to go out into daylight when you can, and get some fresh air at the same time. This is timely advice — research published this week found that Brits spend a total of just six hours a week outdoors in the winter months.
Ryberg drew a contrast between lux levels (the EU standard measurement of light intensity) for a good office desk (500 lux) and going outdoors on a bright sunny day (where you will get 100,000 lux). “That’s a vast difference! Even on a grey day you may get 5,000 lux. Ten times as much as in the office.”
Ever get a mid-afternoon slump? Ryberg said that when we use only electric light we starve our brains, leaving our chronobiology confused as to whether it’s day or night, and consequently whether we should be awake or asleep.
But activating our circadian rhythms not only means lots of sun, but also lots of dark at night, too. Practicing good sleep hygiene means no screens in the bedroom, proper curtains and no bedside lamps.
However it’s worth noting that just like our diets, we all have different light needs. Young people need less than old people, women are also better at color vision than men. Ultimately, our eyes use the fastest moving muscles in our body — muscles that we all too easily forget to exercise.
“When we sit indoors the eyes get lazy and slow, but you can train those muscles. A few minutes of eye yoga a day [moving your eyes in their full range of movement, without moving your head] while waiting for a train will keep your eyes fit.”
Ryberg would like to see all of us considering what our own light prescription might be. “Not only will you have more energy, sleep better and feel happier, you might live longer too.”