Sunday, February 18, 2007
God of the Appendix: Of Truth And Worms
[OK, here I go, stepping off a cliff. Can't say why I want to, exactly. ]
Of Design and Darwin, the appendix speaks to me. With my finger through a hole in the abdominal wall, I sense it, and at two in the morning it tells the truth.
In the appendix, we have a thing within us of no demonstrable value, but which is capable of doing us great harm. People may argue at the edges, but there are two things we know with central certainty: the presence of the appendix kills a lot of people or makes them real sick, and its absence is of absolutely no consequence. Evidently, that's a threat to the concept of intelligent design/creationism, and in a sort of endearingly weak effort, Ken Ham, a major ID guru, once tried to explain it away. Believe it away. Faith it away.
If you take a position in matters of science, says I, you need to keep at least one hand on the fact wall at all times; otherwise, you fall down. So whereas I'm not the first to address the appendix as religious icon, I'm only aware of a couple of people talking about it who've held a thousand or so in their hands. That's concrete: I assert my credibility. (The article to which I linked above has a reference to an article by a surgeon. It's from the same website, "Answers in Genesis," and is impaction-full of the same sort of pseudoscientific assertions. The author is an evolution denier and a creationist.) In the human body there's no other structure of any importance that feels and looks like a silly noodle, and which varies in people from a little stub to several inches long. (I hear one of you thinking something, and you should be ashamed of yourself.) I've removed a bunch of 'em, and I (nor anyone else) have never seen an adverse consequence of appendiceal non-existence. But I've seen a hell of a lot of carnage from appendicitis.
Here are examples of the arguments about appendicoloid importance in the article I cited.
"Today, the appendix is recognized as a highly specialized organ with a rich blood supply. This is not what we would expect from a degenerate, useless structure."
Highly specialized? As defined how? Recognized by whom? He offers as proof of the appendix's function, a statement that the appendix has function; lacking are any actual studies. And it hardly has a rich blood supply. It does have blood, alright: it's alive. But rich? The stomach has a rich blood supply: it's fed by several arteries, coming at it from all directions. You can hardly kill the thing. The appendix? A single artery, the bare minimum, I'd say.
"The appendix contains a high concentration of lymphoid follicles. These are highly specialized structures which are a part of the immune system. The clue to the appendix’s function is found in its strategic position right where the small bowel meets the large bowel or colon. The colon is loaded with bacteria which are useful there, but which must be kept away from other areas such as the small bowel and the bloodstream."
Like most of the intestinal tract, the appendix has lymphoid tissue. Which in and of itself proves nothing. Take out the appendiceal lymph tissue, it might cover the nail of your pinkie. From the rest of the GI tract, you could haul it away in a bucket. Nor is its location a "clue," absent any data to support the assertion. Mr. Ham shovels us an implication that the appendix has something to do with keeping bugs out of the bloodstream: a statement only, with no proof, no studies. A theory perhaps? To the contrary: take out an appendix and poof: no bugs in the bloodstream. Appendicitis, on the other hand, seeds the bloodstream with bugs in many a victim. Bacteria in the small bowel? Plenty of 'em, especially right next to the appendix. He implies the appendix keeps them out. It's simply silly to say such things.
"Through the cells in these lymphoid follicles, and the antibodies they make, the appendix is ‘involved in the control of which essential bacteria come to reside in the caecum and colon in neonatal life’. Like the very important thymus gland in our chest, it is likely that the appendix plays its major role in early childhood. It is also probably involved in helping the body recognize early in life that certain foodstuffs, bacterially derived substances, and even some of the body’s own gut enzymes, need to be tolerated and not seen as ‘foreign’ substances needing attack."
The quote within the quote is from the surgeon's treatise, on the same website -- so in effect, the article quotes itself. Again, an assertion, made up out of whole cloth. Not a demonstration, not an even an attempt. Why? No evidence. Couple of scientific words. He goes on to say the appendix is "probably" like the thymus. Probably? How so? PROBABLY?? What kind of science is that? We know a great deal about the thymus' function in early life. Removal in infancy has significant consequences, demonstrably. Removal of the appendix in infancy has none that have ever been shown. In fact, it's in infancy that the appendix is most deadly: because appendicitis is harder to diagnose in a babe, rupture before discovery is more common at that age than in older people. If I'd had a magic way to remove it from my newborn son, I'd have done it. But here's the best stuff:
"But if it has a function, why can it be removed without ill effects?
Our body has been brilliantly designed, with plenty in reserve, and the ability for some organs to take over the function of others. Thus there are a number of organs which everybody agrees have a definite function, but we can still cope without them. Some examples:
*Your gall bladder has a definite function—it stores bile from the liver, and squirts it into the intestine as required to help with the digestion of fat. However, it can be removed and the body will cope—for instance, by secreting more bile continuously.
*You can cope with having a kidney out, because there is still enough kidney tissue left in the other one. (In the same way, a part of the Gut Associated Lymphoid Tissue, which includes the appendix, can be removed, and the remaining lymphoid tissue will usually be enough to carry on the total function). You won’t suffer from having your thymus out (if you’re an adult), because this extremely important gland, which ‘educates’ your immune cells when you are very young, is then no longer required. This is likely to be very relevant to the appendix."
Yipes. Except for the appendix, there's no organ out with which we can do without some chance of problems. Removing the gallbladder, while tolerated by most people, is associated with known and specific problems in a number of patients. It even has a name: post-cholecystectomy syndrome. He might have mentioned the spleen: you can live without it. But there are known risks: increased chance of blood clots, and increased susceptibility to certain life-threatening infections. Without flim-flam, we know the exact functions of these organs. The kidney analogy is so self-evidently stupid as to require no comment at all. And the "likely to be very relevant to the appendix" statement pretty much speaks for itself: another assertion ex cathedra. Because the appendix threatens his world-view, he's making stuff up: no function has ever been demonstrated, and no adverse consequence of its absence has ever been shown. There's no other organ about which it can be said. Face it, guys: the appendix is useless. (I mean it no offense. After all, it's put bread on my table.) That's just what the facts are: the sun rises in the East, and the appendix is useless. Assimilate it.
The study I cited most often to my patients when asked about adverse consequences of appendectomy is one done by the Mayo Clinic: they studied records of thousands of patients who'd had appendectomy, and compared them with equal thousands who hadn't. (Back in the day, it was very common during any abdominal operation to remove the appendix. Like flicking a bug off your shoulder. No extra charge: just did it to prevent further problems: took an extra couple of minutes, is all.) The groups were statistically similar in every way other than presence of the worm. There were no differences in incidence of any disease. It's as convincing as it gets, given the impossibility of doing a prospective double-blind study.
That the appendix has no unique or physiologically important function is as certain as it can be, based on what we can easily observe. I know it from direct observation, from operating countless times. Maybe if it weren't for us surgeons saving fertile people from their vermiformera, the little rascals would be gone by now. But the existence of a vestigial organ which, when it does anything at all, only does harm, is a threat to certain narrow religious views. Vestigial bespeaks evolution, so let's make something up. I find that interesting. And I find the attempts to will it away amusing. If you don't like certain facts, make up some new ones. If the facts don't fit your faith, change the facts. That sort of thinking has been known to start wars. And it gives faith a bad name.
By its existence, the lowly and useless appendix would seem to deal a fatal blow to the idea (at least Ken Ham's version) of Intelligent Design. Slain, by that ignoble worm, that surgeons'sidekick, my midnight mistress. If you deny evolution, then you have to say the designer wasn't paying attention, says the appendix to my scalpel; or the designer acted deliberately to stick within us something which serves only to harm. Even more scary. Unless, of course, you're a general surgeon.
Addendum: a study in Sweden found an increase in Crohn's disease after appendectomy (we're talking very small numbers here). What's not clear is whether we're seeing chicken or egg: ie, is it that people who will develop Crohn's are more susceptible to appendicitis, or does appendectomy somehow increase susceptibility to Crohns? Interestingly, appendectomy has been associated with a lower incidence of ulcerative colitis. And appendectomy before age ten, in this study, seemed to have no impact at all. To me, that suggests that the Crohn's link, if real, is indeed that Crohn's disposition is causing the appendicitis in that small subset of people. In other words, as you get more toward the age when Crohn's occurs, you'll see more of the connection. If appendectomy caused Crohn's, you'd expect the effect to show in the young kids as they grew up. Or at least I would.
[Update, 8/09]: In another (and quite unrelated) thread I've been asked about this study, which argues that the appendix could function as a sort of storehouse to replenish bacteria in the gut. In fact, it's an interesting speculation, but is no more than that. Also, it states that appendicitis is due to defect of some sort in the immune system -- made with no data to confirm. The study makes plausible extrapolations from the evidence that the appendix has evolved at least twice in certain animal lines. To leap from that to the idea that there must be a function in humans, and to propose without evidence what that function might be is hardly dispositive. The fact remains that in many studies of the appendectomized among us, no real evidence has emerged of a negative impact. Not at a rate that is very suggestive. And the paragraph above this suggests if there are effects, they about cancel each other out. Given the numbers of appendectomies done around the world, it's logical to think something would have shown by now. Nor does the study in this paragraph give credence in ANY way to the out-of-the-orifice statements of Ken Ham.]