Alittle daylight goes a long way. But what does sunlight do for us, and what do we miss when we’re stuck indoors?

Our bodies are guided by circadian rhythms, 24-hour cycles in our biology and behaviour that make us feel alert during the day and sleepy at night.

Exposure to sunlight in the mornings helps to keep your circadian rhythms working properly, and it has been linked to better sleep quality and lower depression scores. The same ipRGCs that feed into the brain’s master clock also connect to the thalamus, a brain area related to mood.

And there’s another important reason to be getting plenty of sunshine: vitamin D. When sunlight hits your skin, it converts cholesterol into vitamin D, which helps build strong bones, and plays a beneficial role in our immune system.

Hospital patients have been shown to recover faster when they have more access to daylight, and researchers think it may increase the number of immune cells that rally to heal an injury.

There’s also some evidence of a link between levels of vitamin D and some viral infections, including the flu and Covid-19. But this isn’t clear cut.

Vitamin D is important for our bones and many of us simply aren’t getting enough. This is especially pronounced in the winter months, when there isn’t enough sunlight to produce the vitamin in our skin, particularly for people in higher latitudes and those with dark skin tones.

Clearly, sunlight is very important for us, and even small increases in your exposure can improve sleep, mood and recovery from illness.

There is still much to learn about how light and darkness affect our biology. Yet as a basic principle, we should all be striving to brighten our days and darken our nights. We evolved on a planet with a 24-hour cycle of day and night. It is time to reconnect with those extremes.

Some easy things we can all do to get more of sunlight and maintain good health:

• Do some exercise outdoors every day, even if it’s just going for a walk.

• Change where you sit so you’re closer to a window. Even a small distance can have a dramatic effect on light levels.

• Use dimmer light in the evenings. You can even buy colour-changing bulbs so you can benefit from blue-light during the day and warm-coloured light in the evenings.

• Listen to your body and go to bed when you start feeling sleepy.

• Use blackout blinds to block the light from street lamps.

• Cut down on your screen time before bed.

Source: www.newscientist.com

Published in Dawn, Young World, October 30th, 2020