Sleep - lighting

This bedtime routine is ruining your sleep, says neuroscientist

The way you brush your teeth at night could be compromising your sleep quality

I know your teeth-brushing routine – in fact, it’s probably identical to mine, and the countless others around the world who all head into the bathroom, flip the overhead lights on, and and get to brushing. However, it may be time to change your typical bedtime routine when it comes to oral hygiene.

According to a talk by Russell Foster, neuroscientist and professor of circadian neuroscience at Oxford University in England, we’ve been brushing our teeth wrong. Instead of relying on light, it may be more beneficial for our sleep habits if we brush in the dark. Speaking to the Royal Society in London, Foster said:

‘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.’

Out of sync

Whilst your body and mind may be perfectly relaxed and ready for bed, when you step into the brightly lit bathroom to spend a few minutes brushing your teeth, you effectively reset your body’s sleep cycle and send it “wake up” signals.

This happens because at night, in response to falling light levels, the pineal gland in your brain starts producing melatonin – the ‘drowsy hormone’ – which helps to ease us into sleep each night. But flipping on that bright bathroom light sends your circadian rhythm spiralling into confusion all over again, and your melatonin back into storage for another time.

As Foster explained our bodies are regulated by the external world and our internal clock, the circadian rhythm, is what dictates when we wake and grow sleepy.

Circadian rhythms have evolved to correspond with the natural cycle of night and day. Depending on whether the sun is rising or falling, hormones start flowing to aid wakefulness or make us more drowsy. Sticking as close as possible to these natural cycles keeps our bodies balanced and ensures better sleep and health overall.

However, because the modern world is now flooded with artificial light, following our inbuilt circadian rhythms is more difficult than you might suspect. Lightbulbs, computers, and the whole host of gadgets and gizmos we use throughout each day, mean that we encounter bright light not just in the morning and afternoon, but long into the evening.

It gets worse

This prolonged exposure to bright light may, according to epidemiologist Richard Stevens be affecting much more than our sleep patterns.

Speaking to UConn Today, Stevens, who has been studying the effects of artificial lighting on human health for three decades said “It’s become clear that typical lighting is affecting our physiology…… While short-term effects can be seen in sleep patterns, “there’s growing evidence that the long-term implications of this have ties to breast cancer, obesity, diabetes, and depression, and possibly other cancers.”

As whilst brushing your teeth in complete darkness may sound impractical and unappealing, it’s worth considering the advice of the scientists. If a total blackout is impractical try swapping your current lightbulbs for lower-wattage bulbs, or even a night light. A few minutes in a dark, or more dimly-lit bathroom might might help you improve the quality of your precious shut-eye, and maybe even your wider health concerns.
