In my first ever college class, we were assigned a book called Why We Get Sick: The New Science of Darwinian Medicine by R.M. Nesse and G.C. Williams. This book answered many questions I had all piled up in my naive pre-med mind- for instance, what is the reason we produce fevers when fighting infection, what is the purpose for feeling instant versus aching pain, etc. After all, I would one day have to understand sickness and explain to patients, why they are sick. If you are interested in thinking about illness from an evolutionary stance, it’s a great read.
Ever since taking that class, I’ve constantly been considering the different ways that humans are simply out-racing evolution. Most of the deaths in the US are due to so-called “diseases of civilization” or “lifestyle diseases” stemming mostly from our readily available food supply and our quick-fix tendencies that lead to addiction (see the short wikipedia article for a definition and examples). We aren’t subject to the same selective pressures as cavemen- evolution basically doesn’t apply to humans anymore. The problem is, we still have the bodies of the cavemen human-folk we descend from. Our bodies evolved to function under certain conditions- eating naturally growing plants and wild meats, sleeping when it gets dark, enduring relatively low stress, living in groups, and living a highly active lifestyle (gotta run from the bears). If a human couldn’t do those things optimally, they’d die, wouldn’t pass on their genes- simple as pie. Yet, with our highly developed brains, humans went from [in a condensed nutshell] being great communicators, to great group-hunter-gathering-nomads, to great growers of things, to civilized. Civilized means yay! no more moving around and chasing animals for food, we can be sedentary and produce all of our food in one spot on a farm! We can all live around the farm! We can use all of our free time we save from not hunting to THINK! Hundreds of years later, that means ideas spread faster than I can even fathom to the point where we have computers and wi-fi and advil and flouresent lights. Yay for civilization for allowing humans to do all this thinking and create all this great stuff that I have. But BOO civilization for absolutely blasting evolution out of the water. We’ve developed in lifestyle, we haven’t developed to physically adapt to these changes.
So what’s the point here? Go back to the diseases of civilization concept- it’s an issue. How can we fix it? Well, one option is to move to somewhere desolate with a group of people and become a hunter-gatherer society with them… I don’t want to do that personally. However, there are little things I try to do that consider my poor little caveman-capacity body. I exercise a lot. We’re built to store energy- we’re also built to USE it. The energy I get from food is (as best my poor grad student budget can afford) natural- lots of plants and very little processed stuff. I try to get a lot of sleep, and I rest when I’m feeling sick. Your body knows when something is wrong and it tells you to STOP so it can fight the pathogens. If a sick caveman without advil tried to go hunting he would be too slow and he’d get eaten by a tiger. If he stayed in his hut while the others hunted, he’d probably live. You see??? Our bodies instinctively want us to live- so listen I what my body tells me. Finally, I try not to put a lot of chemicals in my body. By chemicals, I mean processed-anything-in-a-bag, nicotine, fake sugar, drugs– I’m tempted to bring up modern medicine– I know, STICKY TOPIC. Medications are great for some people- lives saved everyday because of advanced drugs that alter tricky bodily chemistry. But drugs can also harmful. I don’t have enough time/energy for this blog entry to delineate everything bad about popping pills. I’ll just add as a final note that sometimes an herbal remedy is a safer, just as effective choice. There is definitely a movement toward natural medicine, as more doctors are catching on to the “diseases of civilization” idea, and choosing remedies that help our bodies naturally fight problems.