Paul Hopkins: Heart of darkness throws light on our well-being

Diarist Anne Frank wrote: “Look at how a single candle can both defy and define the darkness.” And she knew about darkness in her short tragic life.

We are amidst the darkness in these short, dank days and never-ending nights where many a candle is lit and lights and heating switched on, earlier than we would like – some 166,000 Irish households (23 per cent) are behind with energy bills, according to Senator Lynn Boylan.

While many suffer from Seasonal Adjustment Disorder (SAD) – and than can be debilitating – we could always look on the bright side of these dark times. Think snuggling up with a loved one, evenings beside a real fire; stews and home-made soup. A nice brisk walk on a frosty morning. Science tells us that the dark – that ghoulish world occupied in our childhoods by the walking dead and things that went bump in the night – is a necessary state for both humans and our animal friends. In fact, nature in all its diversity.

Darkness maintains the natural circadian rhythm, so you know when it is night and when it is day. Most animals are much more sensitive than humans and can even sense light that is indistinguishable to the human eye. “Humans have the advantage that we can protect ourselves from light that we perceive to be harmful, for example by darkening our bedrooms. Other animals do not have this possibility,” says Jari Lyytimaki, senior researcher at the Finnish Environment Institute.

According to Lyytimaki, bats and the majority of insects, to take one example, are crepuscular (active at dawn and dusk) or nocturnal creatures. Even a small amount of light can prevent them from behaving as Nature dictates.

The health gurus are continuously telling us that we need on average six to nine hours of sleep a night, and, if you want to sleep as well as possible, you need darkness. According to my psychologist friend from Magherafelt, the quality of sleep is simply better in the dark than in the light. “Melatonin is the main sleep-producing hormone in humans. The body produces it in large quantities only at night and in the dark. Melatonin production is clearly dependent on the amount of light outdoors,” he told me over a hot chocolate the other night.

Seemingly, remaining in steady light all the time is not good for us. If you spend long periods of time indoors or stare a lot at the blue light of screens in the evening, the amount of artificial light will remain too even. As a result, your body clock will not receive vital messages about the time of day, making it more difficult to eventually fall asleep.

“It is important for a person’s inner clock that it is dark at night and that there is a lot of light in the morning. Variation in the amount of light keeps the body clock regular, helps you sleep better and improves your mood,” says my psychologist friend.

According to research in the US and in Israel, irregular body clocks have been linked to many diseases, such as hypertension, type 2 diabetes, depression and asthma.

That said, the darkness – and as I get older I like it less – is a dwindling, eh, resource. As the amount of artificial light increases in cities and elsewhere, total darkness threatens to disappear from the world. In Ireland in the 1960s, only 80 per cent of rural households had electricity – now, the Christmases of the past decades we light up just about anything that moves, concerns for the national grid cast to the wind, not to mention the bills.

Darkness is easily misunderstood. It is often considered something scary and bad without us really thinking why this is. One research suggests it is important for us to curb our irrational fears about the Bogey Man and to remind ourselves that darkness helps protect the environment and improve human health.

The small town where I lay my head, I find the problem is that there is quite a lot of bad lighting that is neither proper light nor proper dark. Driving at night is no longer appealing.

The shortest day of the year will pass on 22nd December. At that point, the Northern hemisphere will be tilted at its furthest point away from the sun, meaning there will be less than eight hours of daylight in Ireland.

It could be worse though. In Barrow, in Alaska, 330 miles north of the Arctic Circle, from 18th November, there are 67 days and nights of darkness.

I'm certain they have candles...