Bizarre but proven fact: US researchers have just discovered women who wear super-tight control underwear actually produce lower-than-normal levels of the sleep hormone melatonin, which could stop their slumber. Rosalind Scutt discusses why your knickers aren't the only sleep thieves out there…
Your pre-bedtime bath
Many of us chill out in the tub before bed, but our bodies are actually primed for sleep by a fall in body temperature, says Dr Delwyn Bartlett from Sydney's Woolcock Institute of Medical Research. "If your bath is too hot and too close to the time you go to bed, this fall won't happen." If you like to soak before you sleep, keep temperatures warm, not hot, and aim to take your dip about two hours before you want to sleep.
Recent research from from Wayne State University in Michigan has linked using a mobile in the hour before bed to disturbed sleep. "We think signals sent by the phone stimulate the brain, making sleep more superficial or harder to achieve," he explains. So don't take calls in the hour before bedtime. Oh, and Facebook/Twitter junkies take note light from computers, laptops or iPhones can also upset your sleep cycle. Japanese researchers found people who use their computer at night sleep about 12 minutes less than others, and feel a lot more tired the next day.
Fatty foods before bed
According to Dr Cibele Crispim at the Federal University of Sao Paulo in Brazil, you'll sleep less deeply and feel less rested in the morning if you ate lots of fat during the day. Another study from the same university showed high-calorie snacks at night may have a similar effect. Neither researcher can say why, but keep evening meals light. Better still, eat something carb-packed like rice and vegetables. University of Sydney researchers have found high-GI foods eaten four hours before bed can make you drop off faster.
The average pillow contains a few hundred thousand dust mites. And studies show if you're allergic to their droppings, you could wake up to 50 times a night something strongly linked to daytime sleepiness. "If you wake up with a dry mouth, it's a good sign that you are 'mouth breathing' at night and allergy could be a cause of this," says Dr John Corbett from Snore Australia. If you also suffer sniffing, sneezing or nasty gooey stuff in your throat, it's likely that dust mites are to blame. Replacing pillows will help and steroid nasal sprays can also calm symptoms.
Ecstasy is the second-most used drug in Australia and we're one of the highest consumers in the world. If you are regularly taking E, or have in the past, be aware: research shows it may mess with your sleep long afterwards. US researchers have found it can increase your risk of developing sleep apnea, which sees you waking up frequently during the night. Normally apnea is associated with overweight, older people, "but our subjects were otherwise healthy young adults", says Professor Una McCann from John Hopkins University. Ask your partner if you snore loudly or snort in the middle of the night if you do, and you suffer from daytime sleepiness, see your GP for advice. Sleep apnea is associated with other health issues like heart disease.
Your bed position
Studies carried out in Iowa found people who sleep with their heads facing north have more disturbed sleep than others possibly because of interference from electromagnetic fields. And according to Mike Lyons, a NSW-based consultant in Maharishi Vedic architecture (building in harmony with nature's laws), the most beneficial way to sleep is with your head facing east.
Research published in the health journal Chest shows smokers go into nicotine withdrawal during the night so you can say goodbye to restorative deep-sleep mode. Instead you switch into a light sleep state, where it's far more likely that something will wake you up. No wonder smokers are four times more likely to wake up feeling tired than non-smokers. Yet another good reason to butt out, we'd say.
Bring on the woolly winter socks! If your feet are cold you'll find it harder to fall asleep and be more likely to wake up in the night than if you keep them rugged up. "Feet often feel cold before the rest of our body because of their relatively poor circulation," says Sammy Margo, author of The Good Sleep Guide (Vermilion, $29.95). "Studies show that wearing socks at night helps stop awakenings." In fact, tumble-drying your socks before bed so they're super-warm gives an even bigger boost you should fall asleep faster if you do!