So, how badly do you wish you could have just slept through this entire winter? There are many ways to hibernate, but one style of hibernation stands out as especially advantageous. You never wake up, you give birth while you’re asleep, and perhaps best of all, you lose your body fat without losing your muscle. Imagine being able to eat as much as you want, go to sleep, and wake up ripped. There are only two animals we know of that can burn significant amounts of fat without losing muscle mass. One is a baby. The other, a bear.
It is hotly debated by experts whether what bears do can be called hibernation. After reviewing the evidence, I stand with those who say it is. It’s simply a hibernation for the big-boned fellas. See, the little guys, like chipmunks, hibernate by lowering their body temperature dramatically. A bat, for example, can lower its body temperature almost to the freezing point. But they keep a food store handy, and every few days they heat up and wake up to eat and defecate before falling back into torpor. A bear, on the other hand, slows its metabolism a great deal, but doesn’t chill its body temperature appreciably. So if you were spooned by a sleeping grizzly, you’d still be nice and toasty, if a little unsafe. What’s more, though a bear can go from being a deeply unconscious heap of fur to 700 lbs of bitchy fury in about 30 seconds when disturbed — again, spoon carefully — it can go up to seven and a half months without waking up once. It recycles its urine for hydration, and is the only animal known to be able to transform urea — the yellow, poisonous part of urine which must be excreted from the body — back into valuable protein. As for defecation, the bear creates a dense “fecal plug” of intestinal secretions and dried poop that corks up the bunghole to prevent any “accidents.”
More than “fecal plugs,” the grizzly and black bears of North America have some ingenious techniques for combating long-term health problems associated with seven months of inertia. The bear’s heart rate falls about 75%, from 80 beats per minute down to 20 beats per minute, causing stagnant blood to pool in the heart’s chambers. In any other mammal, this would cause congestive heart failure. Bears avoid this by switching over to metabolize a different strain of myosin, the protein that regulates heart muscle movement, resulting in a weaker contraction that keeps the blood pressure stable with a slower heartbeat.
Then, of course, there’s the matter of fat and muscle. Bears don’t store food for hibernation in a little pantry like chipmunks do; they store it all in their bodies. Despite the slowed metabolism, a grizzly is still burning 8,000 calories a day during hibernation, and can lose up to 30% of its body weight. A human being in a coma for seven months would also burn a lot of fat, but would lose a significant amount of muscle to boot. The unfortunate truth about muscle is that if you don’t use it, you lose it. (Muscle degradation through disease, disuse, or malnutrition is known as cachexia, or more commonly, college.) Yet grizzlies and black bears can pass out for half a year and wake up lean and mean, having lost weight with hardly any muscle loss. What’s going on here? And more importantly, how can we do that?
Researchers at the University of Barcelona discovered that grizzly plasma contains a unique chemical agent which arrests the protein breakdown associated with cachexia. Bear plasma also prevented muscle loss in lab rats, even when they did nothing but smoke pot and play Xbox all day. The applications for humanity is obvious: if we could metabolize fat for energy while retaining muscle mass, bed-ridden patients would stay healthier. In fact, if we could learn to induce hibernation in astronauts on long interstellar journeys, bear plasma could keep us healthy until we reach new horizons of human exploration in deep space. But you and I both know the only thing we want from this scientific endeavor is an answer to the age-old question, How can I get drunk on eggnog, sleep through the next three months, and wake up with a bikini bod?
We don’t have anything to prevent muscle loss, but we do share something in common with a sleeping bear: fat-burning fat. It’s called brown fat, and it’s common to both hibernating animals and newborn human babies. In fact, when we are born, brown fat makes up about 25% of our body mass, mostly around the back and shoulders. Unlike regular “white” fat, which is simply fuel, brown fat is rich in mitochondria — the power plants of cells — and thus burns energy rather than simply storing it. (Mitochondria’s machinery is largely made of iron, which gives brown fat its distinctive color.) When we’re infants, the brown fat is what heats us; we are born without the ability to shiver, and brown fat metabolizes lipids to produce heat. After a few weeks, we learn to shiver, and the brown fat disappears… or so we thought. It was recently discovered that we retain trace amounts of brown fat in our necks.
You see where I’m going with this, fellow lazypants.
I’m not saying it’s a cure-all. I understand that the body is superb at maintaining homeostasis, and any attempt to shortcut the body’s system will probably result in a backlash. But I also know that skinny folks tend to have larger brown fat deposits than fat people, and that a mere 1 lb of brown fat can be responsible for 20% of the body’s weight loss. And I know that bears have plenty of brown fat which helps heat their bodies on cold winter nights. And I figure that the ability to cultivate brown fat as adults, coupled with a bear’s ability to arrest muscle loss, could potentially mean finding the holy grail of snooze-button hitters everywhere: the key to humanity’s ability to hibernate. Oh, sure, we’d need to figure out how to slow our metabolism and maintain unconsciousness, and then there’s some unpleasant business about butt plugs. But in the big picture, we’re talking about a major leap forward in human evolution: how to avoid the month of February entirely. Hell, let’s take off March, too, and wake up with washboard abs in April. I think it’s high time that humanity exploited the genius of grizzly bears. Let’s make the ability to hibernate a reality. Wake me up when it happens.