All of the advances made in public health, medicine, and nutrition within the past century have been achieved through scientific experimentation and observation: all of them. Therefore familiarity with the scientific method has particular bearing with regard to health-related topics because these are areas that have immediate application to our daily lives. Furthermore, the fact that a lot of us are interested in these topics results in a huge number of heavily marketed hypotheses, some of which have some plausibility, many of which do not.
The scientific method is an elegantly simple process that is also the best way yet discovered to separate the truth from wishful thinking. The practice involves a series of steps: first you observe something and develop a hypothesis, which is a conditional explanation of what you have observed, then use it to make predictions. Next—and this is the most important part—you gather evidence to test those predictions by using either experiments or further observations. Finally, you amend the hypothesis then repeat the testing process; you keep doing this until you minimize the differences between your predictions and the actual observations. Lastly you have your conclusions reviewed and replicated by your peers in order to make sure that your interpretations of the observations are sound. If you are fortunate enough to gain consistency between your experiments and your predictions the hypothesis becomes a theory, which is often used in the vernacular to mean an incomplete or untested idea but in scientific terms is actually a well-supported structural framework that can be used to explain observations and to make predictions. That’s it! While it is certainly true that science gets more convoluted as you dive deeper into it, at its core it always follows these simple rules.
Many popular claims actually follow the scientific method nicely until they get to the point where it becomes necessary to test the purported hypothesis, after which point they rely on argument rather than evidence, which is not scientific. Even the cleverest arguments can be trumped by meager experimental or empirical evidence.
Aristotle, it is said, argued that women don’t have as many teeth as men. As the story goes however, he never bothered to check and verify his assertion… men and women do indeed have the same number of teeth (at least on average). The point is that, while reason is important, arguments, no matter how authoritative, eloquent, or how much we want to believe them, are not enough to determine whether a testable hypothesis is correct. Sound reasons or strong intuitions that something ought to be true don’t guarantee that it will be.
An understanding of how to think about what constitutes science is the most important thing you can have to help you sift through the bad health and nutrition information (and all other information for that matter). However, I am not implying that in order to be a sound decision-maker you need to go out and become a lab-coat-wearing scientist, nor am I suggesting that those who are vocational scientists are somehow superior to anybody who is not. I am merely suggesting that we can all benefit in our daily lives if we adopt a scientific frame of mind when we evaluate information.
It is interesting to note that, though we may not initially realize it, we actually encounter practical scientists in many places in our daily lives. Consider, if you will, your auto mechanic. Although most mechanics I have known do not identify themselves as scientists, in fact they are. If I take my car into the shop with no more than a basic description of what is wrong (“it’s making a kerchunking sound every time I shift gears”) it is the mechanic’s job to hypothesize, based on his or her experience, what the problem may be. S/he will then test to see if the hypothesis was correct by fixing this part or that (I can’t really use any good terminology here because I really know nothing about cars). If S/he was right, great, the problem is solved. If not, it’s time to try something different. Mechanics do this until they fix the problem. It could even be argued that they have an advantage over more obvious scientists because they have nothing to gain by clinging to their original hypotheses and so don’t bother justifying why they should have been right; they simply go with the evidence. Now most of us would not take our car to a mechanic who, instead of amending his or her initial hypothesis until the problem was fixed, gave us rationalizations, but many of us have followed the advice of people who do this with our health.
Bertrand Russell, who was critical of many of the scientific advances of his time (the atomic bomb for example), nonetheless argued that “the scientific temper is capable of regenerating mankind and providing an issue for all our troubles.” Due to the simple fact that, in my day, I have been taken in by many a health charlatan, it is my goal to spotlight some of the techniques used by these impostors to separate us from our money, and very often, our health and well-being.