Fitness Files: The key to so much: sleep
I’m stand-in nanny for my 2-year-old granddaughter these days. My daughter, who works in film production, had two night shoots — when she works all night, overseeing complex coordination of thousands of production details.
Her husband, who also works in film, is flying all over the U.S., doing similar work. He FaceTimed us on a recent night, eyes red with exhaustion. He’d been up since 3 a.m.
Leaving my house the day before, I grabbed a magazine to read at my daughter’s — the October issue of Scientific American. The cover story: “The Power of Sleep — why it’s key to improving cognition, memory, mood and health.”
Sharing fascinating snippets of the article this morning, after one of my daughter’s all-nighters, she snapped at me, “The last thing I want to hear is sleep-deprivation research!”
Was my timing off?
So, I’ll share with my readers, who can’t talk back.
Early in the sleep article, author Robert Stickgold quotes Alan Rechtschaffen, a 1970s sleep researcher: “If sleep doesn’t serve an absolutely vital function, it’s the biggest mistake the evolutionary process ever made.”
It’s not.
Overall, let’s call sleepy time integrative — consolidating human chemistry to promote the immune response, optimal hormonal distribution and enhanced mental outlook and learning.
First, consider the dramatic interaction with the immune system: In two studies quoted, healthy people were inoculated against hepatitis. In the first, half the subjects were allowed normal sleep, while the other half were kept awake one night. Four weeks later, the “normal sleep” group produced 97% more antibodies to the virus than the sleep-deprived.
In a second research project, subjects received hepatitis inoculations, then wore sleep-monitoring devices. In a lengthy trial, researchers determined that antibodies increased 56% for every additional hour’s sleep, in direct contrast with those who “averaged less than six hours sleep a night… [They] were seven times more likely to have such low amounts of antibodies [that they] were considered unprotected against… the hepatitis virus,” rendering the inoculation ineffective.
If immune system attacks weren’t enough, sleeplessness could make us fat. Studies monitoring changes in hormonal function with sleep deprivation found a whopping 40% decrease in the ability to clear insulin from the blood of the sleep-deprived. Other studies found that with only two night’s limited sleep, the amount of ghrelin, an appetite-stimulating hormone, jumped 28%, while leptin, which “signals the brain that there is no need to eat,” decreased by 18%.
“The Negativity Bomb” section follows. Stickgold starts with this strong statement: “Despite the remarkable effects of restricted sleep on immune and hormonal function, the greatest impact probably occurs in the brain.” With only one night’s sleep deprivation, the ability to learn showed 40% deterioration over those who slept. The test was word recall.
And here’s the bomb: Words with negative connotations “appeared to be at least twice better retained [by the sleep-deprived group] than positive or neutral words.”
So my daughter snapped at me not because I’m irritating, but because of what Stickgold calls “the horrifying possibility that the sleep deprived form twice as many negative memories of events in their lives as of positive.”
Depression could be related to sleep deprivation. Findings come from treatment of people with sleep apnea, a condition in which breathing irregularities awaken people many times a night. Treated with a CPAP device, which allows normal nighttime breathing, former apnea sufferers found a 20% reduction in symptoms of depression.
Finally, trash the old notion that memories are mainly about the past. “Sleep seems to care mostly about information likely to be in future relevance.” During sleep, we take what’s happened and prepare to meet new situations or “take the information already stored and … juxtapose different possibilities to find the best solution to a problem.”
Yeah, I want that sleep-produced insight for myself!
And I sure want it for my adult offspring. However, they join their age mates in working hard, raising kids, slicing in time for family and exercise and cheating on sleep.
I’ll borrow Stickgold’s final sentence but desist from reading it to my daughter. “Taken together, the results of studies looking at the role of sleep in hormonal, immunological, and memory functions suggest that if you do not get enough, you could — besides being very tired — end up sick, overweight, forgetful and very blue.”
I wish my family and the world a good night’s sleep.
