Six ways sleeping more will make you healthier
In April 1970, Frank Cole was driving home from a party to his parents’ home in Melbourne when he began to feel drowsy.
In the chilly early hours of Sunday morning, the 21-year-old had on the heater in his EJ Holden and was following his cousin’s car.
But after a week working on a sheep farm he was exhausted, and soon felt his eyelids getting heavy.
“I felt myself drifting off, then the next thing I knew I had wrapped my car around a power pole,” Mr Cole said.
He was later to learn he had broken his neck and jaw, and would need to spend months in hospital before he was well.
It is a stark reminder of the dangers of sleep deprivation, a condition that nearly cost him his life, and is becoming more common in the developed world.
The Chernobyl nuclear disaster of 1986 and the Exxon Valdez oil spill in 1989 have both been linked to sleepy workers.
“It is quite likely that sleep is serving an absolutely fundamental process,” said Dr Amy Jordan, who is a sleep expert and senior lecturer at the University of Melbourne’s psychology department.
“If you take rats and sleep deprive them continuously, they will die after about 70 days. It is not like they all die from heart attacks … They actually die from complex and various reasons,” she said.
And yet people continue to ignore their body’s needs.
Everyone knows they feel better after a good night’s sleep, but new research is starting to unlock the secrets of how, with evidence it affects the body in ways that were completely unimaginable just a decade ago.
Scientists are starting to figure out how sleeplessness impacts on cancer, Alzheimer’s, obesity and poor school results, among other things.
The number of people with sleep disorders in Australia has risen sharply since 1998. Photo: AIHW
Melinda Jackson is a senior research fellow at RMIT University’s Health Sciences school who has investigated sleep’s effect on the body.
She said despite commonly held beliefs that people could easily catch up on a string of late nights by having a long sleep on weekends, it may be much harder to regain normal functioning once we have become sleep deprived.
“Fantastic data has just come out, laboratory data, that has shown that after a week of sleep restriction it might actually take five nights of 12 hours’ time in bed for someone’s performance to come back to their baseline level,” Dr Jackson said.
The 24-hour work cycle of modern society and ubiquitous forms of brain stimulus like smart phones, tablets and TVs are causing people to drift from the in-built circadian rhythm that our bodies have been created to work within over many thousands of years.
So how does this affect people?
1. Road trauma
Roads are particularly dangerous for sleep deprived drivers.
Sleep deprivation is linked to road deaths.
Superintendent Bob Rennie from NT Police said someone who was awake for 24 hours had the equivalent of a blood alcohol reading of 0.05 per cent, a level that would be illegal in Australia.
“I have put people into body bags who have fallen asleep behind the wheel,” he said.
Figures from the NT Government show more than 10 per cent of motor vehicle deaths in 2014 had fatigue as a factor.
In Western Australia the Office of Road Safety puts the figure in that state at 30 per cent.
2. Alzheimer’s disease
Plaques on people’s brains associated with Alzheimer’s disease may be linked to lack of sleep. Photo: ABC
One of the most startling discoveries in recent years is the role sleep plays in preventing dementia.
For years it was known that people with symptoms of Alzheimer’s commonly had sleep problems, but studies have now shown a link between sleep loss and brain plaques, a hallmark of the disease.
A 2013 study showed evidence that the connection between the two goes in both directions, with Alzheimer’s plaques disrupting sleep, and lack of sleep promoting the plaques.
“When we looked specifically at the worst sleepers, those with a sleep efficiency lower than 75 per cent, they were more than five times more likely to have preclinical Alzheimer’s disease than good sleepers,” said Assistant Professor Yo-El Ju on a Washington University blog.
Australia’s population is ageing, with more than 50 per cent of people in a study of 12,000 reporting they regularly felt tired.
Cancer’s spread has been linked to sleep patterns.
Dr Jordan from the University of Melbourne said work out of the United States had shown that rats injected with cancer cells had the disease spread far more quickly if the animals were sleep deprived.
“Certainly if you have cancer and you have on top of that sleep deprivation, then the cancer gets worse quicker and progresses further into the bone,” Dr Jordan said.
“I believe the mortality was higher in the animals that were sleep deprived as well, so they died from their cancer sooner,” she said.
A large study done on nurses had also shown health problems in nurses that did shift work were more common than those who worked only in the daytime, Dr Jordan said.
“They have higher rates of cardiovascular disease, they tend to be more overweight, and they have higher rates of cancer.”
4. Anxiety and depression
Links between sleep disorders and depression have been well documented in numerous studies but as more data trickles in the full extent of the relationship is becoming clearer.
In 2005, a study published in the journal Sleep found people with insomnia were nearly 10 times more likely to have clinically significant depression than others.
The same study showed insomniacs also were more than 17 times more likely to suffer from anxiety.
Sleep well and you won’t feel as hungry: study.
Dr Jordan said people deprived of sleep or who have disrupted sleep experience changes in blood glucose levels that could predispose them to adult-onset diabetes.
“There are changes in how much you eat, so people who have had four nights of just getting four hours of sleep a night, if you give them a free buffet, they will consume on average about 500 calories more than someone who is well rested,” she said.
It is also thought that sleep-deprived people could be too tired to exercise, or be awake for longer, giving them more opportunities to eat.
6. Academic results
South Korean students were seen sleeping in class. Photo: ABC
Again in the US, a study looking at more than 43,000 students found the impact of sleep deprivation had as big a role in academic performance as binge drinking and marijuana use.
Psychiatry professor Mary Carskadon from America’s Brown University told the ABC that said that good sleep after learning enhanced gains made the day before.
“Sleep prepares for learning by enhancing alertness, attentiveness, motivation, and decreasing irritability, distractibility, and moodiness,” Professor Carskadon said.
She said there was evidence that with certain types of learning, students were rewarded with a roughly 15 per cent gain in examination results.