Note: I have a Naturocrit Podcast episode titled "The Naturalness Fallacy" in which I deal with this issue, too.
001. Udo Schuklenk writes at thewhig.com in "The Absurdity of Labeling Things as 'Natural'"]"(2014-02-28)[my comments are in unquoted bold; his blog is here]:
"use any Internet search engine [...] and search for ‘natural’ [...] you will find that ‘natural’ is a very common feature in advertisements for all sorts of beauty and health products as well as in value judgments about all sorts of human activities [...] an endless stream of advertisements for quack products like ‘natural’ flu remedies [and] ‘natural’ health care generally";
natural, in my view, is rather meaningless or nebulous. But, because it is used so much in commerce as a label, I think people are quite trained to respond positively to it as a marketing label. There's something about it which is almost subliminal and reflexive.
"surely it has something to do with a romantic view of ‘mother nature’ taking care of its own. The reality is, of course, quite different [...]";
"there is no good reason to exclude ourselves or the things that we produce from nature, and pretend they are something other than natural [...] however, there is no reason to assume that things we create are bad just because they are produced by us. Everything that is physically possible should sensibly be considered natural [...] we should not fall for such marketing claptrap [...]";
"our natural process of dying typically is a pretty nasty one. Disease is unpleasant. That’s why we invented medicine. Get over it. There is nothing wrong with using modern medicine to ease our way out of a miserable death. It is also quite all right to interfere with other natural processes such as cancer busily growing in our bodies [...]"
in my view, civilization itself isn't natural if you regard animals in the wild, which humans once were, as 'natural'. Civilization itself, including language, clothes and soap, is synthetic. I half-jokingly tell my students this in medical science courses, sometimes: natural is meaningless, it is a placeholder for actual information. It's malleable, like the trailer at the beginning of a movie that wants you to project into it as it entices and therein find your wants in purchasing that product.
"whether a particular product then is conducive to our well-being is simply a matter of scientific evidence. This has nothing to do with how it came about [...] it is not a big surprise that purveyors of natural health products use deliberately vague marketing spiels to sell their stuff [...]";