Why Astronauts Get Osteoporosis (And What it Means to Us On Earth)

4611583232_0484ea0d52_zSometimes there are things that are such assumed constants that we totally forget about them and the fact that they have an impact on us.

Did you hear the joke that started off David Foster Wallace’s brilliant commencement speech at Kenyon College- This is Water? It goes like this, “There are these two young fish swimming along, and they happen to meet an older fish swimming by. He nods at them as he swims past and says, ‘Morning boys! How’s the water?’. And the two young fish swim on for a bit, and eventually one of them looks over at the other and says, ‘What the hell is water?’” David Foster Wallace goes on to say, “The point of the fish story is merely that the most obvious and important realities are often the ones that are the hardest to see and to talk about.” He then gives a gorgeous talk on living a compassionate life. But I am going to hijack the beginning of his talk to point out one crucial form of of “water”,  or “obvious and important reality", related to our bodies:

Gravity is always present.

Unless we leave this planet, or go to some awesome space camp where we get to play with NASA’s equipment or something, gravity is constantly exerting its force on us.

The way that I will usually illustrate (or rather exaggerate) this with my clients is to have them stand in whatever way feels normal to them, and then gently press down on their shoulders. With this exaggerated form of gravity, they will often notice things like all the force being transmitted to their low back or their knees. I will then help them to find proper alignment, and again mimic exaggerated gravity by gently pressing on their shoulders. Once they have found proper alignment, they now feel the force of gravity transmitted evenly through their joints and traveling directly down into the ground through their feet.

But let’s imagine you do opt out of this whole gravity thing. You’ve just decided to pay Richard Branson a whole lot of money to go into outer space. What might that look like? Oh wait, plenty of people have already gone there, we call them astronauts. Let’s take a look at what astronauts have taught us about gravity. Did you know there is something called The Bone Research in Space Symposium? Am I the only one that thinks that sounds like an awesome conference to attend!? It’s brought to you by the good people at The International Space Life Sciences Working Group who go by the charming and impossible to pronounce acronym ISPLSWG! I digress...

Research like this, on astronauts and what happens to their bones, exists because when you take a human out of the gravitational field they rapidly develop osteoporosis. I’m talking a pretty lightening fast bone to cotton candy switcheroo. Ok that is a tad of an exaggeration, but it is pretty shocking how rapidly density is lost.

From speaker Rene Rizzoli at the symposium: “"Bone is a living tissue, and must be 'stressed' [via gravity] to maintain strength. If bones are immobile for long periods, as occurs in space but also in bedridden patients, the individual will lose a substantial amount of muscle and bone mass, which may have serious repercussions,"

I would like to amend this a bit to read, “As occurs in space, bedridden patients, and also in a more subtle and gradual way to misaligned and undermoved tissues in normal healthy populations.”

So we can clearly see it’s not so sunny when we opt out of gravitational forces because we are designed to thrive here on Earth, where there is gravity. Which means we have to find the most optimal way to live in gravity (i.e participate for most of the day in natural human movements like walking, lifting, and not sitting still) so that the signals to our cells create a nourishing effect, instead of a degrading effect. In the words of my favorite biomechanist Katy Bowman, “Alignment matters!” It matters kind of a lot actually!

And because I couldn’t have said it better myself, here is Erik Dalton:

I often scratch my head in wonder when reading research that dismisses the effects of gravitational exposure on human viscoelastic tissues. It’s even more frustrating when scientists and clinicians discount the role distorted postural faults such as pronated feet, crooked SI joints, and forward heads play in commonly seen pain syndromes. Each-and-every day, the weight of gravity (14.7 pounds per square inch) pushes straight down on our bodies. These compressive forces should be equally distributed throughout the neuro-myo-skeletal system…but are they? Prolonged one legged standing (excessive weight bearing on one limb) is an oft-overlooked culprit creating ligamentous creep that may be a precursor to more serious conditions like joint laxity, lumbopelvic instability, sprains, and osteoarthritis.”

But hey, if you want to find out what it feels like for yourself to be totally out of gravity, NASA will pay you for the opportunity! However, as a woman who spent a a portion of her pregnancy on bed rest, I'm here to tell you no amount of money is worth it. So you may prefer to get upright and delight in the gravitational field that we all take for granted.

*P.S. This is an excerpt from a short book that I'm currently working on, which is why the blog is about to go silent for a few weeks. I'm behind on my deadline! But I'll be back soon.

photo by Scorpions and Centaurs