Key sleep habit could increase risk of chronic illness

A new study has found sleeping with even a small amount of light can increase your risk of chronic illness.

While some households have televisions in the bedroom and many of us are guilty of falling asleep on the couch, experts say the light can have a detrimental effect on your health the longer you are exposed to it.

Dr Carmel Harrington told Today Extra people need complete darkness to get a healthy sleep and the brain won't rest if it senses light is still on.

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"The idea is that the brain needs to feel safe so if there's light around, the brain stays on a bit of alert because it doesn't know what's going to happen," Dr Harrington told Today Extra.

"You've got to go back to our evolutionary start and caveman days when we needed quiet and dark so that our brain knew it was safe.

"If there's lot of noise around or light we actually don't properly get the restorative sleep we need as much."

Dr Harrington said a recent study suggested exposure to light could increase your risk of insulin resistance or metabolic dysfunction like diabetes and other cardiovascular diseases, because you are not getting consistent good sleep.

For people who have a habit of falling asleep on the couch, Dr Harrington suggested avoiding the couch altogether if you are feeling tired and go to bed if you are yawning or already have heavy eyes.

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She also suggested not watching television right up until the last minute before you head to bed.

"Have a nightly routine that involves switching off one hour beforehand," she said.

"Some people can't sleep without some light on or can't get to sleep so maybe introduce a timer on your bed lamp or, alternatively, if you really find it difficult sleeping in the dark I'd recommend a dim red light rather than a white light."

Watch the full interview with Dr Harrington above

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