Things we didn't evolve with

The shower is a great place to get some thinking done. White noise to block everything else out; warm, meditative environment. My shower-thinking sessions are particularly stellar when I've been camping and climbing or skiing a lot, and haven't had a shower in a while...

These days, one of my favorite shower-thinking topics-of-choice is our society's unhealthy relationship with health. After reading an article titled "Dietary lean red meat and human evolution" by Neil Mann some years ago, I started to consider our "diet fads" in light of evolution. That is to say, since evolution occurs over millions of years, how can this brand new product, promising to lower your blood cholesterol! can possibly solve problems we didn't have only a few centuries ago -- problems that, interestingly, have only arisen in the same time period as their supposed solutions. Considering a longer timeline could give us insight into what our bodies are actually evolved to digest, and therefore how to nourish ourselves, not just feed ourselves.

Perhaps the invention of margarine could be considered the spark that ignited decades of research, theories, and myths about the health benefits and detriments of various items in our diet, both natural and otherwise.

Debate has whirred around the various nutrition fads for decades, if not more. As one gains favor, others are forgotten. And as things re-appear on our grocery mart shelves, we forget to ask where they came from in the first place.

I guided Norman up Mt. Whitney this past September, taking the long way around via Cottonwood Pass to the south. We had many very interesting discussions, and I came to see that many nutrition myths can be deciphered using a lot of common sense and a bit of scientific study.

What does it meant to be hydrogenated, for example? In the process of hydrogenation, food chemists add hydrogen atoms to a certain molecule of fat in order to alter its physical state: add more hydrogen atoms to a fat that is normally liquid at room temperature, and it will now be solid at room temperature. This is useful when you want to use cheaper oils to do the job butter is supposed to do.

But the new structure, with carbon molecules now saturated with hydrogen atoms, is devoid of the high-energy double bonds between carbon molecules -- reducing the energetic benefit we incur upon digestion.

And all the current hype (or rather, anti-hype) about trans fats? When a certain fat molecule is heated, it reaches a point at which its structure is strained, and flip-flops into what's called the trans form of the molecule. The consequence: your body's enzymes, specifically designed to attach to the naturally-occurring form of this fat molecule, will no longer be able to attach to the fat molecule, meaning your body cannot break it down.

In much the same way, scientists have been looking at the role of grain in our diet, and are finding that our bodies are rather ill-equipped to digest seeds, which have become a major part of our diet in just a few thousand years -- not enough time for our gut to evolve to digest it.

So what should we eat? Things we can hunt and gather: lean meats, and seasonal fruits, vegetables, some seeds. But of course, we couldn't sustain the whole world with this strategy, and that gets to a whole other issue.

As I was scrubbing away, washing the grime that had built up after days of skiing and camping, I started listing other things we haven't evolved with: cars, television, soap...

Does evolution explain the deer's classic "deer-in-the-headlights" look when facing sure death by car? Freezing in place might fool a mountain lion, but not a car.

Then there are the Dene women of way northern North America who become emotionally tied up in the lives of their favorite soap opera characters -- because the only people they know are real ones, not fake ones who exist solely in a lighted box.

And it hit me. Did prehistoric man use soap? Soap must have come after the domestication of animals, when people combined animal and vegetable fats with other things to cleanse themselves. But certainly they weren't using detergents such as sodium lauryl sulfate?

All I know is that my skin and hair feels best after a week of bathing in mountain streams. And now, post-shower, my skin is dry and scratchy. I think Evolution is telling me to spend more time in the mountains.