by Mark Sisson: Dear
Mark: Your Brain on Junk Food
They're only the tip of the iceberg. I've had a few u201Cdefinitiveu201D
topics up my sleeve for a while now, and grains are it for today.
Yes, grains. I know we've
given them a bad rap before, and it's safe to say I'll do it
again here. Sometimes the truth hurts, but you know what they say
about the messenger, right? Without further ado…
Grains. Every day we're bombarded with them and their myriad of
associations in American (and much of Western) culture: Wilford
Brimley, Uncle Ben, the Sunbeam girl, the latest Wheaties athlete,
a pastrami on rye, spaghetti dinners, buns for barbeque, corn on
the cob, donuts, birthday cake, apple pie, amber waves of grain….
Gee, am I missing anything? Of course. So much, in fact, that it
could — and usually does — take up the majority of supermarket square
footage. (Not to mention those government farm
subsidies, but that's another post.) Yes, grains are
solidly etched into our modern Western psyche — just not so much
into our physiology.
Those of you who have been with us a while now know the evolutionary
backdrop I mean here. We humans had the pleasure and occasional
scourge of evolving within a hunter gatherer existence. We're talking
some 150,000 plus years of hunting and foraging. On the
daily scavenge menu: meats, nuts, leafy greens,
regional veggies, some tubers and roots, the occasional berries
or seasonal fruits and seeds that other animals hadn't
decimated. (Ever seen a dog at an apple picking?) We ate what nature
(in our respective locales) served up. The more filling, the better.
And then around 10,000 years ago, the tide turned.
Our forefathers and mothers were on the brink of ye olde Agricultural
Revolution. And, over time, grains
became king. But, as countless archaeological findings suggest,
people became smaller and frailer as a result of this new agrarian,
Ten thousand years seems like a long time, doesn't it? Think of
all the house projects you could get done, the advanced degrees
you could earn, the dinner party recipes you could try out, the
books you could read. Almost oppressive, isn't it? But our personal
vantage point on the span of 10,000 years doesn't mean much
of anything when the context is evolution. It takes a lot
to drastically change a major system in the human body. We're talking
a way bigger change than trying out the latest flavor of Malt-O-Meal.
Grains were certainly not any substantial part of the human
diet prior to the Agricultural Revolution. And even after
grains became a large part of human existence, those who were deathly
allergic to them or had zero capacity to take in their modest nutrient
value were, in all likelihood, selected against. And pretty quickly
at that. Those whose health was so compromised by grains that they
were rendered infertile early in life were also washed out of the
gene pool. That's how it works. But if you can limp along long enough
to procreate (which was considerably earlier then than it typically
is now), that new fangled diet of grains got you through. No matter
how stunted your growth was, how awful your teeth were, how prone
you were to infection.
When I say humans didn't evolve eating grains, I mean our
digestive processes didn't evolve to maximize the effectiveness
of grain consumption. Just because you can tolerate grains
to a certain degree, as just about all of us can (thanks to those
earlier folks hitting the end of the genetic line), doesn't mean
your body was designed for them or that they're truly healthy for
you or — especially — that you can achieve optimum health through
them. We're not talking about what will allow you to hobble along.
We're talking about the foods that offer effective and efficient
digestion and nutrient absorption in the body. And that's all about
evolutionary design. If you're not after optimal health,
you're probably reading the wrong blog. But if you want
to work with your body instead of unnecessarily tax it, if you want
to focus your diet on the best foods with the most positive impact,
you most definitely are reading the right blog. Now let's continue.
Among my many beefs with grain, the first and foremost is the havoc
it plays with insulin and other hormonal responses in the
body. For the full picture, visit the previous Definitive
Guide to Insulin from some months ago. Guess what? The same
principles still hold. We developed the insulin response to help
store excess nutrients and to take surplus (and potentially toxic)
glucose out of the bloodstream. This was an adaptive trait. But
it didn't evolve to handle the massive amounts of carbs we throw
at it now. And, yes, we're talking mostly about grains. Unless you
have a compulsive penchant for turnips, the average American's majority
of carb intake comes from grains.
The gist is this (as many of you know): Whatever the carbohydrate,
it will eventually be broken down into glucose, either
in the gut or the liver. But now it's all dressed up with likely
no place to go. Unless you just did a major workout or are finishing
tying your running shoes as we speak (which would allow those grain-based
carbs to be used in the restocking of depleted glycogen stores or
burned as secondary fuel, respectively), that French baguette will
more likely get stored as fat.