Good morning, gang! (Is it still morning? It feels like morning…)
For those who remember my Fat Bear Week post, a quick follow-up: According to the National Park Service, the early risers of the grizzly population in Yellowstone are now emerging from their long winter’s nap.
The first, a male weighing in at a lean 300-350 lbs, was spotted breakfasting on some bison jerky in the eastern part of the park. I guess no one told the poor guy that not only is this the day when we humans monkey around with the clocks, it’s also National Sleep Week — one of my favorite holidays. In fact, as meditation teacher Jay Michaelson says, sleeping is “the one thing I prefer to being awake.”
One of my favorite experts on sleep is Matt Walker, PhD, whose book Why We Sleep: Unlocking the Power of Sleep and Dreams is an fascinating and eye-opening (pun intended) examination of all things somnolent. Here are a few of my favorite takeaways:
the evolution of sleep
There’s a lot of talk in the low-carb community about “ancestral health.” That is, eating and moving like our ancestors did. But when you think about it, sleep is kind of silly from this perspective.
If you’re a caveman, living cheek by jowl with lions and tigers and bears and stuff, lying down and spending several hours unconscious is really a terrible idea. It’s a behavior that can turn you into another critter’s fourthmeal right quick — the very kind of thing that, one would think, would be natural-selected out of the gene pool years ago.
But that hasn’t happened. Science has proven time and again that despite millions of years of evolution, the human body and brain still require a good 7-9 hours of quality sack time per night. This fact alone, Walker says, is proof that sleep is incredibly important for our survival:
“Yet sleep has persisted. Heroically so. Indeed, every animal species carefully studied to date sleeps. This suggests that sleep evolved with—or very soon after—life itself on our planet. Moreover, the subsequent perseverance of sleep throughout evolution means there must be tremendous benefits that far outweigh all of the obvious hazards and detriments.”
Walker goes on to speculate that, far from being an add-on to our our existence, sleep may be our original, primordial state, existing long before this thing we call wakefulness.
sleep on the brain
Citing a number of recent studies, Walker shows that without sleep, there is no learning. As he says in his viral TED talk Sleep is Your Superpower, “You need sleep after learning to essentially hit the ‘save’ button on those new memories.” Newer studies have even shown that a sleep-deprived brain will have trouble taking in new information. The brain becomes like a sponge that is “waterlogged, as it were, and you can’t absorb new memories.”
Speaking of memory, I’ve been posting about Alzheimer’s and dementia lately, and there, too, sleep has a role. We know that both memory and sleep quantity tend to decline as we get older. Walker’s recent research suggests that these two things are interrelated — that “the disruption of deep sleep is an underappreciated factor that is contributing to cognitive decline or memory decline in aging, and most recently, we’ve discovered, in Alzheimer’s disease as well.”
Sleep is when the brain’s clean-up crew, called the glymphatic system, washes away the metabolic waste that builds up in the brain during the day. An incredible analogy: imagine that your brain is New York City. While you sleep, the buildings all shrink to half their size, and a big river washes through the streets and cleans out all the garbage. This is what your neurons do. In effect, “wakefulness is low-level brain damage, while sleep is neurological sanitation.”
No sleep, no cleanup, and the junk begins to accumulate. Metabolic waste becomes amyloid plaque, one of the hallmarks of Alzheimer’s. Walker and his colleagues are using this knowledge to pioneer sleep-based treatments that, he hopes, will help restore memory and cognitive function.
take your bedicine1
One more takeaway that’s particularly timely: today is the most dangerous day of the year for your health. Why?
“Because there is a global experiment performed on 1.6 billion people across 70 countries twice a year, and it's called daylight saving time. Now, in the spring, when we lose one hour of sleep, we see a subsequent 24% increase in heart attacks that following day. In the autumn, when we gain an hour of sleep, we see a 21% reduction in heart attacks. Isn't that incredible? And you see exactly the same profile for car crashes, road traffic accidents, even suicide rates.”
On top of that, short sleep has a disastrous effect on your immune system. After just one night of being restricted to 4 hours of sleep, participants in one study saw a 70% drop in the activity of natural killer cells — the immune cells that are key in fighting off everything from viruses to cancer. In fact the WHO has called nighttime shift work a “probable carcinogen.”
sleep braggadocio
Meanwhile, I had this text exchange with my buddies just yesterday:
In the end, rocker Warren Zevon did come to rest 20 years ago, when, at the age of 56, he succumbed to cancer. Would Zevon still be around today if he’d gotten more Z’s? Impossible to say. But it’s enough to give one pause.
Zevon is by no means alone. It’s so common to hear people at the office or in the media brag about how little sleep they get. It’s a way of portraying ourselves as busy, energetic, and otherwise important. Walker points to three famous examples: Winston Churchill, Margaret Thatcher, and Ronald Reagan, who each claimed to get by on only 4 hours a night, and were quite proud of it. But he also reminds us that in the end, Churchill suffered from cardiovascular issues, and both the Gipper and the Iron Lady went on to develop Alzheimer’s.
Walker says that far from “an optional lifestyle luxury,” sleep is “a nonnegotiable biological necessity.” He believes that all of us — from children to the elderly — are suffering a “silent, sleep-loss epidemic.” But all is not lost:
“I believe it is now time for us to reclaim our right to a full night of sleep, and without embarrassment or that unfortunate stigma of laziness. And in doing so, we can be reunited with the most powerful elixir of life, the Swiss Army knife of health, as it were.”
If you’re having trouble getting enough sleep, here are Walker’s top two tips:
Regularity is king. Go to the bed at the same time every night, weekday or weekend.
Keep it cool. Aim for a bedroom temperature of around 65 degrees Fahrenheit. Some people also find that taking a hot shower before bed opens the capillaries on the skin and helps facilitate the drop in temperature that will bring on sleep.
So: improving memory and creativity, fighting disease, extending lifespan and health span… You can see how I was only half-joking when I texted my friends that sleep is the most productive thing I do all day. As Walker puts it, “Sleep is probably the single most effective thing you can do to reset your body and health.”
Good night, and good luck!
Special shout-out to my buddy Bill for this excellent portmanteau
Interestingly enough, your friend Jen has been struggling with sleep. I hope she sees this post.