A simple way to nod off at night: brush your teeth in the dark

Could this simple trick be the key to getting a good night's sleep? Photo / iStock

The secret of a good night's sleep may be as simple as brushing your teeth in the dark, an Oxford neuroscientist has claimed.

Russell Foster, professor of circadian neuroscience, claims that the bright fluorescent light of bathrooms wakes the body up just when it should be switching off.

He believes that simply brushing your teeth in a dark room can allow sleep to take hold more quickly.

"Sleep is the single most important behaviour that we do. Across our lifespans 36 per cent of our life will be spent sleeping," he said following a lecture on sleep at The Royal Society in London.

"Often people will turn their lights down at night which helps to get the body ready for sleep, but then they will go and brush their teeth and turn their bathroom light on. That is very disrupting. I often think someone should invent a bathroom mirror light which has a different setting for night-time."

Lack of sleep is known to reduce cognition and suppress the immune system as well as raising the risk of obesity, diabetes, cancer and mental illness. But Prof Foster said people often struggled to regulate natural sleep patterns because they spend so long under artificial light that confuses the body about the time of day.

The invention of the lightbulb has meant bright light is available 24 hours a day which can confuse the body's natural rhythm and cause genes to switch at the wrong time.
A recent study by US scientists found that sitting too far from a window at work can knock 46 minutes off a normal night's sleep.

"We live in these dimly-lit caves, both at home and in our offices, which are far less bright than natural light, even on a cloudy day. So it is so important to get outside, particularly in the morning to reset the body clock," said Prof Foster.

Also speaking at the Royal Society event, Jonathan Coe, author of the novel House of Sleep, said he thought that sleep deprivation was not helpful for creativity.

"All these moments when you're half awake, half asleep. I often think that is going to be a creative time, but when I look at what I've actually come up with I usually reject it," he said.

"The ideas that come to you in those moments are not always as good as you think they are."

Prof Foster added that dreaming was important to help the brain make new connections. "During the day there is all this information flowing in and you can't adequately process that information so you park it," he said.

"In sleep the options open out and it's like lots of jigsaw pieces flying out. You might come up with a solution to something that has been bugging you."