Sleep is critical for achieving optimal health, safety, and productivity in life’s pursuits. It plays a critical role in metabolism, immune function, muscle growth, energy, mood, learning and memory.

Did you know?

4 in 10 Australians frequently suffer from inadequate sleep.

In 2016-17, sleep deprivation was linked to 3,017 Australian deaths - 394 deaths from falling asleep while driving or from industrial accidents and 2,623 deaths from heart disease or diabetes.

  • A number of notable accidents and disasters have occurred due to sleep deprivation.
  • Medical errors and traffic accidents are also significant contributors

Being awake for 16 hours or more causes changes in brain activity

Sleep deprivation costs Australians $66.3 billion annually.

The Facts:

Almost 20 years ago, sleep research pioneer, William Dement MD said, “You’re not healthy, unless your sleep is healthy”

Wakefulness and sleep occur from the actions of two opposing internal forces

The body has a biological clock (circadian rhythm) that controls the daily oscillation of different bodily functions, including body temperature and neurohormone secretion

White (visible) light is made up of all the colours of the rainbow. Of these colours, blue light has more thermal energy and will affect your ability to get the recommended 7-9 hours of sleep per night, while red light has the least power to shift circadian rhythm and suppress melatonin

What can we do about it?

Light. Make sure you are exposed to 10,000 lux for 30 minutes every day – that’s full daylight (not direct sun). The best time to do this is early in the morning, between 6.00 and 8.30am, when the circadian rhythm is the most responsive. In winter, exposing eyes to natural light, even on a cloudy day, will produce a favourable response.

Devices. Turn off all screens, including TV, radio, music devices and mobiles, to help your mind and body switch off well before bedtime. This allows melatonin and cortisol levels to normalize

Caffeine and Alcohol. These affect adenosine, a neurotransmitter which decreases neural activity and facilitates sleep

Schedule. A regular sleep schedule keeps the circadian sleep/wake cycle synchronized, resulting in fewer reports of insomnia and depression

Gut microbiome. Microbiota activates the vagus nerve, affecting the circadian clock, which in turn regulates the microbiota

Exercise. This enables falling asleep faster with more time in deep sleep and less night time awake

Inner Chatter. Worrying about a problem or a long to-do list can be a recipe for insomnia

Relaxing rituals. Follow relaxing and enjoyable daily rituals before bedtime to help you fall asleep and sleep well

Sleep environment. Blocking out light, quietness, comfort and ambient temperature are key


Sleep plays an important role in maintaining good health. Practising good sleep hygiene will help you to not only feel better, but will also protect your heart, brain, metabolism and mood.

Dr. Lillian KentPhD, MAE, MPH, BSc (Hons), FASLM
Dr Lillian Kent graduated from Melbourne University with degrees in Microbiology and Biochemistry, Deakin University with PhD and Master in Public Health, and The Australian National University with a Masters in Applied Epidemiology. She is a senior research fellow in the Lifestyle Research Centre at Avondale College of Higher Education, a Fellow of the Australasian Society of Lifestyle Medicine, and a Registered Public Health Nutritionist with the Australian Society of Nutrition. Her research interests focus on the relationship between lifestyle and the prevention, treatment and reversal of chronic disease, particularly in LMICs.