As a medical student, we are often told that half of what we are being taught will be proven false by the time our careers are over. The problem is, they don’t tell us which half.
I found this proposition a little hard to believe. It seems that there are enough facts that we know to be true, that we should be able to fill up a curriculum with true stuff as opposed to ideas that are unproven. www.PubMed.com has more than 23 million citations. If a quarter of them are true, that should be at least enough to fill up a curriculum.
When professors cite the “half of it is wrong” made-up statistic, I think they are mostly referring to the idea that medicine is constantly evolving and many procedures or medications will be irrelevant in the relatively near future. This is true to an extent, but there are also a series of ideas or concepts that are incomplete or just flat wrong. One of them that particularly gets under my skin is the following, which I’ve seen presented at conferences and lectures:
The immune system is a series of cells and molecules made by the body to attack pathogens (bacteria, viruses, etc.). However, sometimes the immune system attacks the host (ourselves), and this leads to clinical diseases such as lupus or rheumatoid arthritis. This is called autoimmunity, and my lab studies some of these diseases. Another situation is when the immune system intrinsically fails to fend off pathogens; this is called immunodeficiency.
Often, when we are taught about the immune system, you see a picture of a seesaw like the one above. The idea is that if the immune system is overactive, the result is autoimmunity, and if the immune system is underactive, you get immunodeficiency. It seems like a logical system model, except that what we know to be true doesn’t support it. If you look at autoimmune patients, they’re actually more likely to get infections. And if you look at immunodeficiency patients (for example, Common Variable Immunodeficiency, a disease I’m studying), they are more likely to have autoimmune disease. So clearly it’s not as simple as a see-saw balance like the diagram above.
Why do we teach wrong things? The answer is certainly up for debate. One idea that I’ll put out there is that we teach wrong things because they’re often easier than the truth. A see-saw is pretty easy to understand; it’s literally a three year-old’s toy. But the reality that these diseases are incredibly complex dysregulated systems …that’s not a toddler playground toy of which I am aware.