Sleep 411: Is Getting Enough Z’s Really That Important?
In this day and age, getting eight hours of sleep is seen by many as a luxury, not a necessity. Moreover – along with the ability to work at any time and in any place – many of us are cutting corners on our z’s.
But proper rest is needed for more than just energy. It balances our weight, hormones and brain activity, and improves our cellular regeneration and heart health, among other benefits. With the increase of fatigue-induced road, mining and surgical accidents, quality of sleep is now under the research spotlight.
How sleep trumps exercise and nutrition
For the last 50 years, food and exercise have been the focus of wellbeing. Yet many people who eat perfectly and gym daily still struggle to maintain their health.
Notes psychologist and professional sleep researcher Hannes Kruger: “Physical activity, nutrition and sleep make up the golden triangle of health. You will only be able to eat well and exercise well if you have good sleep. People who rest well feel physically better, more in control and don’t [engage in] emotional eating.”
Much like lack of exercise and a bad diet, long-term sleep deprivation has been shown to increase the risk of lifestyle diseases. Click here to find out how you can set up your bathroom to improve your sleep.
Tuning the cycle on sleeping
The circadian rhythm, our natural day-and-night pattern, regulates all metabolic processes – including sleeping – via the hormone melatonin. But for sleep to commence, we first need enough sunlight. Daylight regulates the pineal gland (our melatonin maker) via the eyes. During the day, cortisol and insulin are produced to keep you awake and energized.
As day turns into night, these hormones give way to melatonin for sleep. For the pineal gland to make melatonin, it needs vitamin D3. Interestingly, 90% of the body’s vitamin D3 is synthesized from the skin’s exposure to sunlight – yet deficiency is quite common, even in people who live in a hot climate. The amount of time we spend indoors and the use of conventional sunscreens appear to be factors.
A 2015 study, published in the journal Sleep, found that subjects with only 50% of required vitamin D levels were twice as likely to be sleeping less than five hours a night, whereas women exposed to good-quality sunlight could fall asleep with ease.
During a good length of deep sleep each night, the glymphatic system (the brain’s waste-disposal unit) gets to work washing out harmful waste created during the day. Scientists now think this system could play a major role in preventing neurological degeneration such as Alzheimer’s.
Weight gain and cravings
It’s time to stop beating yourself up over food cravings. Resent research suggests hormones control your cravings, not willpower.
“Hormonally you are more stable when you sleep well,” suggests Kruger. “The parasympathetic rest and digest, and the sympathetic fight and flight, are linked to your hormonal systems.” Without enough rest, the body and brain are unable to properly regenerate and reboot – and therefore can’t produce enough energy for the day. The brain considers this an emergency; it increases cortisol and insulin to keep blood pressure and blood glucose high enough to keep you going.
According to Harvard University, cortisol also boosts your hunger hormone (ghrelin) and reduces your satiety hormone (leptin). The less you rest, the more you eat. The priority fuels for the day become fats, salt and carbohydrates, and the metabolism is slowed to preserve energy. Cortisol and insulin also make you store body fat.
A recent study conducted by the Sleep Image Institute in the United States, How to lose weight by doing absolutely nothing, reveals that less than seven hours of sleep a night increases obesity by 6%. But each extra hour of being asleep (between six and nine hours) decreases incidence of obesity by 30%.
Click here to find out why sleep-deprivation affects each of us differently.
The price of sleep deprivation
For the last century, experts have assured us that we don’t need more than six or seven hours of rest a night. But this does not appear to be the case. The World Health Organisation is now clear that each person needs eight hours of sleep (six cycles of 90 minutes) a night.
A lack of sleeping certainly doesn’t do our mood or memory any favours. “The brain needs to work twice as hard when suffering from sleep deprivation,” suggests Lewis. “And negative things tend to be encoded into your memory better than positive experiences when you are sleep-deprived; over time this can trigger depression. During states of exhaustion, the brain has micro-sleeps, meaning parts of the brain, or the whole brain, can briefly turn off while you think you are awake.”
And Dr Charles A Czeisler, professor of medicine for sleeping at Harvard Medical, says: “We now know that 24 hours without sleeping or a week of sleeping four or five hours a night induces an impairment equivalent to a blood alcohol level of .1%,” which means you are legally drunk!
While the long-term effects of minimal sleep slipped under the radar, the aging process got the blame. The inflammation caused from limited sleep is often responsible for forgetfulness, and loss of muscle and skin tone. But that’s not all. A 2015 study found that chronic sleep disturbance predisposes an individual to cardiovascular disease, metabolic dysfunction, psychiatric disorders and early mortality.
“We have grown to believe that a better body and more success means sleeping less, work harder, but the science is showing otherwise,” concludes Kruger. “I love the idea that I can teach my children that this is something to love and cherish.”