After a (reasonably) refreshing holiday break, Lagniappe is back. Thanks to everyone who kept doggedly hitting this site during the last few days - I admire your persistance.
I notice from my site's counter that I get a small but steady flow of Google hits for various miracle cures. I said some nasty things about the Budwig flaxseed-oil diet a while back, for example, and I still get Googled for that one. For those visitors, here's a post that (with any luck) will show up for a long time to come.
To put it in one sentence, distrust simple cures for complex diseases. Cancer is a complex disease, so are arthritis, MS, Alzheimer's and diabetes. What's a simple disease? An infectious one: there's a proximate cause, and a path to cure it. Get rid of the bacteria, and your septicemia goes with them. Clear out the parasites, and no more malaria. (You'll note that we don't have a universal malaria cure yet, which should say something about how hard even the simpler diseases are.)
The really tough ones, though, are all things that originate from some misfiring of the body's own systems. It's true that there are single-gene diseases, which would be simple to treat if we only knew how to get gene therapy to work. Most of them are rarities, diagnostic zebras that many physicians will never see. The ones that every physician sees are multifactorial and very hard to deal with.
I've spent a lot of time on this site talking about autism recently, and there's a common factor. I believe that many diseases only look like single conditions, which turn into dozens of other diseases on closer inspection. There's no such disease as "cancer," for example. Cancer is the name we sloppily apply to the end result of dozens, hundreds of metabolic or genetic defects and breakdowns, all of which end up as vaguely similar cell-differentiation diseases. It wouldn't surprise me if Alzheimer's ends up as something that can be caused several different ways, all of which end up in the same alternate low-energy state for the brain's metabolic order. (I speculated on this back in the first month of this blog's existence.)
And autism, too, could well be the name we're giving to several different diseases, distinguished by their time course, onset, and severity, caused by all sorts of intricate interplay - the wrong chord played on the instrument at just the wrong time.
You can, at times, find single factors that lead into these diseases - a compound called benzidine leads to bladder cancer, for example, although not in every person exposed, and at unpredictable exposures over unpredictable times. But that doesn't mean that everyone who has bladder cancer has been exposed to benzidine - not many people ever are these days. And stomach cancer, for example, has nothing to do with benzidine at all. Even the simple cases aren't too simple.
Remember the power line scare? How those electromagnetic fields from high-tension lines were messing up everyone's lives? You could see stories about how power-line exposure had been linked to brain cancer, to kidney cancer, to skin cancer. The problem was, one study would show a barely-there tenuous link to brain cancer - but not to anything else. Another would show the same wispy possible connection to kidney cancer - but not to anything else. And so on - after looking over all the data, the best conclusion was that this was all statistical noise. Beware statistical noise - that's another long-running theme around here.
Epidemiology hasn't been a simple field since the days of yellow fever, if it even was then. And medicine hasn't been a simple one since the first days that ever counted. As time goes on, we're clearing out more and more of the easy stuff. The really hard stuff is what's left, and it's going to be resistant to simple fixes.