We here in Skepticville are in for a long cold and flu season. The downside is that everyday we will continue to be flooded with, often questionable, tips for "boosting our immune system." The upside is that those of us who blog about skeptical things will not have a shortage of material to talk about, particularly when it comes to making medical terms a little bit less esoteric so that we can make better decisions.
When it comes to the term/phrase "boosting your immunity," I really like the way Dr. Mark Crislip over at Sciencebasedmedicine.org explained it. Many people seem to think that the immune system is like the muscles in our arms; they are either weak, average, or can be made super strong by doing a lot of exercise and maybe boosting our protein intake. Actually, the immune system is more like an automobile, you can have a gas tank that's empty (bad), topped off (good), or overfilled (also bad); you can also have tires that are flat (bad), optimum pressure (good), or overfilled (bad), or exploding (really bad). So, you don't want a weak immune system (flat tire), but you also don't want one that's working over time either (overfilled or exploding tire).
If your immune system really was "boosted" you would essentially be causing an inflammation in your body that could lead to nasty things like blot clots, which could in turn cause a heart attack, a stroke, a pulmonary embolism, an amputation of one of your limbs, etc. All things that most of us are trying to prevent by eating better, etc. And think about it, for those of us that are miserable during "allergy season" the source of our misery is basically an immune reaction that is not normal (and who wants to be miserable longer than necessary). Diseases like Type 1 diabetes mellitus and celiac disease are the result of an inappropriate immune response. Have I convinced you that "boosting" your immune system is not something you want yet?
Ok, ok, so some of you are saying "Yeah, but I haven't exactly taken good care of myself lately. Shouldn't I take this vitamin, or this herb, etc to optimize my immunity?" Well, first of all there isn't any good evidence that any of the herbal products work, including one of my favorite's from the 1990's, echinacea. Second of all, let me go back to the car analogy for a bit. If you found out your car was running low on gasoline, you wouldn't put oil in the gas tank, you would put gasoline in the tank. If you were using up the gasoline faster than you want, you will find ways to economize. In the same vein, if you haven't been getting enough sleep, then you need to work on getting more sleep, taking extra vitamin C, etc. will not fix your problem. And if you have trouble getting enough sleep, then you need to figure out why and try to correct if possible (maybe you need a darker room, or not drink caffeine after a certain hour). If your diet is poor, then work on correcting your diet. If your vitamin D is low, then start supplementing. In other words, figure out where you are operating at less than optimal and then try to fix that area, don't try to overcompensate somewhere else.
And don't forget, you can actually protect yourself against certain viruses (like certain kinds of influenza strains, measles, etc) by getting a vaccine against that particular virus. In other words, you can activate your body's normal immunity by updating your vaccinations and encouraging family members to do the same. I work around people who do have suboptimal immune systems for a variety of reasons, and so I make sure that I do my part to keep them from getting sick by getting my flu shot.
Take home message--get enough sleep, eat healthy, get exercise, wash your hands, and stay up to date with your vaccines. Keep the machinery of your body running the way it's suppossed to and fix specific problems as they arise.