According to the New York Times, "Autoimmune disease affects an estimated 50 million people at an annual cost of more than $100 billion." Why? Because we're too clean. We're destroying our "inner ecosystems" as the article puts it. We're hand-sanitizing and sterilizing our food supply to death (literally). In this case, the saying "paranoia will destroy 'ya" is becoming a self-fulfilling prophecy. We're so afraid of bacteria that we're over-cleansing our lives, putting our bodies into biological backfire. Basically, by removing every nuance of benign, biological threats, the body gets lazy. It becomes complacent and ends up with its defenses down when the serious stuff comes our way. Surely you've heard about food-borne bacteria putting people in hospital (and causing cross-country vegetable paranoia every six months or so), but the real problem is that most people's immune systems are so weak that they can't handle a little bit of bacteria that our ancestors lived with daily! Eating vegetables straight out of the garden without rinsing them is not the solution, however. You still need to wash them. There's a delicate balance between protecting yourself from parasites and overdoing it to the point of destroying your body's good bacteria. Speaking of overdoing it, hand sanitizers are a quintessential example. As Dr. Al Sears says in a blog post he's titled "Why I Don't Use Hand Sanitizer":
Some even hypothesize that the world’s relatively recent obsession with hand sanitizer may be making our immune systems hypersensitive to common allergens like gluten. Not to mention, hand sanitizers don't do much good against viruses like norovirus, either. And in at least one study, washing with good old soap and water worked better against diarrhea-causing bacteria. So the lesson here is don't be afraid of every little germ, wash your hands at logical times, and what doesn't hurt you makes you stronger.