These days it's easy to fight a bad night's sleep the day after with coffee or energy supplements. But research reveals that nightly eight hours might affect more than whether we feel dozy during an afternoon meeting. Sleep can affect how much we earn, what we eat and where we live.
That's what journalist David Randall discovered in researching Dreamland: Adventures in the Strange Science of Sleep (Norton, $25.95), which explores the little-understood world of sleep, a science that many believe is on the cusp of its golden age.
Randall says he was inspired to write the book after he started sleepwalking and went to a doctor for help. "Science doesn't know much about sleep," his doctor told him. Prescription: Take it easy and hope it doesn't happen again.
"People forget about sleep because they think it's this break from life, this elegant on-off switch," Randall says. "You forget it's a third of our lives. That third is a missing part of the puzzle in terms of how we live."
He spoke by phone from New York; this is an edited version of the conversation.
Q: Why is sleep such a little-understood science?
A: We still don't really know what (the evolutionary purpose) of sleep is. It's not just rest, because you can rest in a hammock all day long, but after about 24 hours, you're going to be in bad shape.
That's one reason sleep scientists feel they're in the golden age of this science.
Sleep scientists only discovered REM sleep in the late '50s, early '60s. Before that - most doctors thought their responsibilities ended as soon as you fell asleep.
Now there are over 75 sleep disorders recognized.
Q: You're unpacking an everyday part of our lives. What did you find most interesting about this topic?
A: The chapter on how sleep helps us learn was fascinating to me. It looks like dreaming is the time our brains make connections to what's important.
You pick up so much information throughout the day: what my voice sounds like, what the person next to you is wearing. Maybe sleep is the time where your brain chucks what's not important.
Q: You say that more than 75 sleep disorders have been recognized. What do studies reveal about insomnia?
A: For a long time people thought that insomnia was a byproduct of depression, and now they're realizing that perhaps depression is a byproduct of insomnia.
Somebody who suffers from insomnia, it's almost like they need sleep so badly, they can't get it. So you can think yourself into that cycle.
Q: How does the culture of sleep differ around the world?
A: One problem several multinational companies have when they open offices in China is that people there still have an afternoon nap. They might fall asleep at their desks. - In Spain there are still siestas, but in 2008 the government curtailed them for government workers. A lot is cultural. You don't want to give up the natural rhythm of life.
Q: There's this growing industry around fatigue management - money being poured into energy drinks, caffeine pills and sleep aids. What do you make of this?
A: There are two parts to it. There's the stimulant side of it, which is the caffeine and coffee drinks - that part is more the reflection of the times. It's so much easier just to forget about sleep, it doesn't necessarily have a really high importance for most people.
The other side is fatigue management, and that's growing. Researchers, businesses and governments are realizing that especially for people who have to make important decisions, some really bad things can happen if you have sleep-deprived people.
[A fire at an oil refinery underscored the need for fatigue-management.] It's not an altruistic thing - these accidents are leading to a loss of money.
