Who doesn't love a good night's sleep? But for many of us, those well-earned zzzs can be somewhat elusive. Work, stress, shift patterns and having young children and babies can all affect how much – and how well we sleep.
But worryingly, how well we sleep can have a huge impact on our health. A recent study revealed that more than eight out of 10 adults globally experience negative impacts following just one bad night's sleep. And only one in 10 people go to their doctor about sleep problems, yet 31% take medication to try to solve the issue.
According to Lisa Artis from The Sleep Council, just one night of interrupted sleep negatively affects mood, attention span and cognitive ability. Each hour of sleep lost per night is associated with a temporary loss of one IQ point, while chronic sleep debt can have a seriously damaging effect on our mental and physical health.
So what kind of problems could we face if we don't get our heads down and get a decent amount of kip?
1. Breast cancer
According to a study in the journal Cancer Research, female shift workers have a higher risk of developing breast cancer than the rest of the female population. The researchers found that sleeping for a prolonged period of time in the dark promotes a healthy level of the hormone melatonin, which suppresses the growth of breast tumours. Conversely, tumours that were exposed to low levels of melatonin – thanks to bright light levels at night – were much more active.
2. Lowered immune system
If you're burning the candle at both ends, it can increase the level of the stress hormone cortisol in your blood, which then suppresses your immune system and makes you more liable to coughs and colds, explains Professor Jim Horne from the Sleep Research Centre at Loughborough University. "If you only get five hours sleep a night, it could have a direct impact on your cortisol levels and cause a lot of psychological stress."
3. Diabetes and heart disease
Not getting enough sleep can also increase insulin resistance, a risk factor for the development of type 2 diabetes and heart disease, says Artis. "Shortened sleep can increase CRP (C-reactive protein), which is released with stress and inflammation. Studies have suggested that people who usually sleep less than five hours a night have an increased risk of having or developing diabetes. "It seems that missing out on deep sleep may lead to type 2 diabetes by changing the way the body processes glucose – the high-energy carbohydrate that cells use for fuel."
4. Weight gain
Can a lack of sleep really cause you to put on weight? According to Horne, there is a correlation between sleep and obesity – but only in those who sleep less than five hours per night. "About 2kg of weight can be attributed to not getting enough sleep," he says. "But to rectify your weight, it would be far better to start walking 20 minutes per day."
One study, published in the Journal of Pineal Research, suggested that sleeping in rooms with ambient light from street lamps or iPads can disrupt the body's production of melatonin, thereby affecting metabolism as well as sleep. Sleeping in pitch black conditions increases melatonin and helps to regulate the conversion of food into energy. You can do this by using a good quality eye mask or blackout blinds/curtains.
Tips for better sleep
It's not the quantity of sleep that's important, it's the quality, says Prof Horne. Follow these tips for a better night's kip:
- Turn on a dim lamp rather than a bright light if you have to get up in the middle of the night, advises psychologist Sharon Stiles. This will avoid sending signals to your brain that it is daytime and you will find it easier to go back to sleep.
- If you're doing shift work, it's not a good idea to come straight home to bed, says Prof Horne, as your body clock will only allow you about five hours of sleep. Delay it until midday and you're likely to sleep better.
- Don't take your worries to bed with you. "Bright light from your iPad can interfere with the natural process of being sleepy," explains Prof Horne. "Try to avoid emails for a few hours before bedtime."
- Make sure that your bedroom is the right environment for sleep – cool, dark and quiet – and that your bed is up to scratch," says Lisa Artis. "Look at the lighting in your home, and avoid foods and drinks that can hinder sleep."