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Saturday, September 25, 2004
The importance of sleep
By Henrylito D. Tacio
HEALTH 101
SCIENCE tells us that sleep is nearly as vital to life as is food.
Yet, scientists are far from answering the seemingly simple question of how much sleep a person really needs.
"There is no simple answer" to how much sleep people need, according to Gregory Belenky, director of neuropsychiatry at the Walter Reed Army Institute of Research in Silver Spring, Maryland, who has conducted extensive research into the effects of sleep deprivation. "Individual by individual, there is a lot of variability," he adds.
A very small number of people appear to need four hours of sleep or less a night. Some experiments in the United Kingdom suggest people can be trained to get all the rest they need in about six-and-a-half hours - without the use of stimulants.
Last year, a controversial study conducted at the University of California in San Diego found that people who sleep six or seven hours a night actually live longer than people who sleep eight or more.
Dr. Daniel Kripke, the lead investigator of the study, said the results don't mean that sleep is dangerous. He said the findings only underscore that scientist don't really know whether human beings need some fixed amount.
People, he pointed out, should avoid routinely using drugs either to sleep more or sleep less. But what is sleep for, anyway? Two good reasons to get plenty of sleep have recently been forwarded by a recent issue of the American edition of "Reader's Digest." For one, a sound sleep seems to be the key to a healthy heart. "As soon as people drift off, levels of hormones that stimulate the sympathetic nervous system during the waking hours, called catecholamines, begin to ebb," explains Dr. Michael Irwin, a research psychiatrist of the University of California at Los Angeles. The result: blood pressure falls. Heart rate slows. Blood vessels relax, making it easier for blood to flow. "Our hearts, in other words, get a much deserved rest," Dr. Irwin says.
When the study subjects are deprived of sleep, the result is exactly opposite. Catecholamine levels go up and raise the blood pressure, making the heart work harder than normal. That added burden, over time, could spell trouble.
Not getting enough sleep can also spell trouble for our body's immune defenses. Recent studies have shown that immune cells may be responsible for commanding sleep. And when we don't obey their orders, germ-fighting cells called natural killers begin to stumble.
But then, is sleep really necessary? Randy Gardner decided not to sleep for 11 straight days in 1964: He was 17, a high-school senior and desperately wanted to win the San Diego Science Fair.
He had recently heard that a disc jockey had gone 260 hours, a shade under
11 days, without sleeping. "I could do that," Gardner told himself.
"I wanted to prove that bad things didn't happen if you went without sleep, that you wouldn't go insane," said the now 56-year-old retiree and still living in San Diego.
With the help of two friends who took turns keeping him awake, marathon pinball sessions and a growing circus of television reporters, Gardner stayed awake 264 hours and achieved his record. In a brief news conference, Gardner said he felt he could another day or two, but the experiment was being conducted over his Christmas holidays and he had to get back to school.
(Readers who wish to write the author can send their email to tasyo2002@yahoo.com)
(September 25, 2004 issue)
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