Corporal Pollution

As I was walking past a classroom today, I overheard someone saying 'you know you have to have cholesterol....'. I suspect that they were trying to emphasize that things like cholesterol serve a purpose in the body, but that they can also cause problems. So you can't simply eliminate them from your diet and body and function. There are a lot of chemicals that are naturally found in the body that serve vital functions, but that can also cause disease. This made me think that people perhaps tend to think of these sorts of materials, not as a part of our biological systems, but more like [i]pollution[/i]. Pollution, like say in a toxic compound emited from a factory into the environment. Which would be the wrong way to think of these biological materials, they need to be there in the first place. You can perhaps fix most environmental problems by reducing or eliminating a pollutant, but you can't necessarily cure disease, fix your own internal biological environment, by doing the same.
And I think that the idea of pollution here certainly has precedent in the context of the body. Here pollution could be thought of in the hindu and jewish sense of caste and ritual pollution of the body. Maybe when most people think of modern issues, like high cholesterol, we aren't [i]really[/i] thinking of it in the rational/scientific/medical sense, but rather in that old ritual pollution sense.