Human Decision-Making: a scary thing
Good science shows that we humans are lousy at estimating risk (references below). And we make lots of decisions based on our estimates of risk. Lots of health decisions are made that way. Let's look at human risk evaluation.
Research by psychologists shows that we pay most attention to the risks that are right in front of us. Risks that won't appear until later, even if they are huge, just don't get to us the way a risk we face right now does. Getting osteoporosis from lack of exercise, and breaking a hip -- that won't become a problem for many years yet, if you're 20 or 30 or 40 years old. What's more a problem, right now, is the fact that you'll be all sweaty when you get dressed for work after a workout -- so you can't exercise before work, or during work, and afterward I'm too tired, etc. etc.
Lots of health decisions are like this. People will start a heart exercise program after their heart attack, when the risk of having another attack is now very clear to them. Those people knew about the value of exercise before the heart attack. They aren't stupid or foolish, they're human: this is what humans do. They pay attention to today's risks, not so much to tomorrow's, and very little to those they'll face 10 years from now.
Worse yet, solutions with immediate strong benefits strike us as much more attractive than solutions with less immediate results -- even if those benefits will be many times greater later! Buy a new TV now instead of investing and letting that money compound interest. Have a doughnut and some coffee instead of investing that time walking around the block twice. Again, this is not stupidity -- this is how our brains work.
Short-run solutions to immediate problems: that is what humans come up with most of the time. And it's understandable. Our minds evolved to handle immediate problems. Is there a saber-tooth tiger out there? Where are we going to find food today? Who can I trust in my social band? Does Joe still owe me a favor? That's what we "grew up" thinking about.
We did not evolve the capacity to think about whether we might kill off too much of our food supply. That was not an immediate risk, like starvation! As a result humans have indeed killed off their primary food supply in some cases. The long term risk of our current behavior is hard to "see", compared to the immediate benefit. Our nervous system is tuned for now, not then.
What can we do about this?
If we cannot really trust our own brains, what then? We have two allies in dealing with our own limitations. First we must recognize this way that our brains will trip us up, and be prepared to work around it. We must recognize that our brains will look for the short-term gain and will not easily "see" the long-term risk. Getting one more important memo written now will "look" more attractive than getting 15 minutes of exercise, almost every time.
Thus, our first ally in dealing with our own natural (evolutionary) short-sightedness is awareness. We must ask ourselves, at least for major decisions like health (or national/international politics), if we've missed some long-term gains or risks because of how our brains typically operate.
We have evolved frontal lobes that give us the capacity to "see" the future, if we pause to do so. This part of our brain gives us reasoning power to come up with solutions that our older, more emotionally driven brain cannot "see". (For a Brain Tour showing you these different parts of our brain, the evolutionarily older "limbic system" and the newer frontal lobes, click those links.) But we must make a specific effort to think this way. Our brains will not automatically work in long-term mode, and instead tend to work in the short-term mode as a rule.
And thus we come to our second major ally for dealing with our own brain: routine. If we establish patterns of behavior we just routinely follow, we don't have to think (and thus run the risk of making a short-term benefit, long-term risk mistake!) For example, consider brushing or flossing your teeth. This is not that much fun, right? If you don't make a habit of it, you're not likely to decide "this morning, I think I'll brush my teeth"! So, you make a routine of it and just do it without thinking.
(You can even think of marriage as one big social habit this way: don't think, just stay faithful/committed, don't make a short-term decision with big long-term losses!)
So, you can use routine to help with health care behaviors that are not that much fun in themselves. taking medications; keeping a mood chart; getting exercise (although that one should be of immediate benefit also). To review then: your allies in dealing with your short-sighted brain are awareness of this problem and routine!
New World, New Mind, Robert Orstein and Paul Ehrlich
This is Ornstein's attempt to explain to poor Dr. Ehrlich why no one's been able to hear his stories of global doom, which are of course accurate even if his time frame isn't (e.g. The Population Bomb). The entire book is devoted to giving examples of how our short-term brain simply can't "see" the long-term consequences of our decisions.
Judgement Under Uncertainty, Amos Tverksy and Daniel Kahnemann
This is a very technical work. One of these days maybe I'll come back and summarize some of it, it's so important. We are so bad at estimating the probability of events, you just wouldn't believe it. Even experts in the field, like statisticians, can't even accurately apply their own mathematical principles, because of our tendency to emotionally get involved in remembering the frequency of events. The authors were really smart guys (Kahnemann is still alive, at Princeton). They got a Nobel for this work, eventually, in Economics, even though the principles apply all over the place, and Kahnemann himself is a research psychologist.