As consumers, we like to think of ourselves as savvy and rational. But marketers have always known better. The health food and dietary supplement industries, in particular, have long made a mockery of the rational consumer.
I think it's a bit unfair to poke fun at consumers who may not know what gluten is, beyond thinking it's something they may want to avoid. I can pretty damn well guarantee none of those people could tell you what asbestos is either. Should they be ridiculed for not wanting asbestos in their attics, too?
Also this:
Do they? Human emotions and "delusions" are what separate us from robots, and last time I checked being happy with oneself and having a feeling of self control are a couple of the most potent medicines. If one chooses to take charge of one's health in a way that works for that individual, far be it from me to tell them they're wasting their time and money. This isn't to say that the food and supplement industries aren't evil. They are. A lot. It's just that in one breath the author acknowledges that health and nutrition are complication, and in the next derides anything that we don't have a clear picture of. Thinking like this (that is, only things which have been measured and are "known to science" matter) is what leads to things like the recommendations that psychologists used to make that parents touch their children as little as possible. The food industry probably gets off on it, because it allows them to run commercials like those that claim that corn sugar is the same as natural sugar.
"Get the facts! You're in for a sweet surprise." Ah yes, the facts. All we need is that which can be easily measured.