Have you ever heard somebody say, “I never get sick?” Or the nonsensical equivalent, “I haven’t been sick in three years (five years, ten years, whatever).” Now is that really possible? I think those that say it have little or no understanding of human physiology.
The human immune system has evolved to distinguish self from non-self, normal and healthy metabolites from foreign invaders. When the immune system encounters a foreign substance, it goes through a cascade of responses that include humoral, cell-mediated, and non-specific immune processes. Our bodies essentially create symptoms (those things most people consider as being sick, but of which I’ll argue is really health) to fight various insults to the body, including microorganisms, toxins, and many cancers. Inflammation itself is a healing process.
To say one never gets sick in the layman’s term (and only a layman would say such a thing), means one never experiences symptoms. To say one never experiences symptoms would either mean the person never encounters a foreign substance (they must live in a plastic bubble), or she has zero healthy response to foreign invaders. Would this be healthy? Would this be possible?
Since I’ve never personally recorded a someone’s health/non-illness status who makes this claim, I have no idea if it really exists, although I’ve certainly explained why I doubt it. If it truly does exist, then I would say to that person, “Watch out–your body’s lack of healthful immune response means that it’s not doing the job it has evolved to.” It is virtually impossible for any human being to not encounter foreign pathogens. Sorry.
Interestingly, allergies are on the rise in developed countries including the U.S. One hypothesis, which I consider highly plausible, is that our drive to never encounter foreign substances (or in other words, our attempt at “never being sick”) through hyper-cleanliness and hyper-vaccination leads to an under-stimulated immune system. Preventing normal/natural exposure to dirt, germs or pathogens causes our immune system to get “bored.” As a result, the immune system begins to attack itself causing allergies (and other auto-immune disorders). This is called the hygiene hypothesis, and is merely one of many hypotheses trying to explain the increased incidence of allergies.
We have evolved an immune system for a reason–the world is filled with opportunistic organisms fighting to survive like every living thing. Our immune system is our natural defense that has allowed us to live in a dangerous world for millions of years. To suggest that one has transcended human evolution by taking supplements, exercising or any other reason people use to tell the world how healthy they are, is complete folly. It warrants a reminder: The expression of symptoms is health–therefore, no illness, no health.